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Birth and the Big Bad Wolf: Biocultural Evolution and Human Childbirth, Part 1
Abstract
In this two-part article, we reflect on the evolution of human childbirth by combining our respective expertise in folklore and interpretive anthropology (Davis-Floyd) and physiologic birth (Cheyney). In Part 1, we follow six little folkloric pigs from the beginnings of human history through to the present, adapting the well-known tale of “The Three Little Pigs and the Big Bad Wolf.” Using this tale as a metaphorical device, we explore complex relationships between humans and nature, society, and childbirth through a description of the six basic subsistence strategies humans have developed over time—foraging, horticulture, agriculture, pastoralism, industrialism, and the technocracy, reflecting on how these ways of life connect to birthing practices. We argue that despite vast cultural differences in the treatment of birth—including those few cultures where solitary birth is valued—premodern, pre-industrial birthways had much in common, such as labor accompaniment, upright positions, and freedom of movement during labor and birth. These similarities were supplanted during the Industrial Revolution with the subsequent growth of technocratic societies and replaced by an also very similar set of birthing practices. However, these technocratic approaches do very little to support, and often even undermine, our evolved birthing biologies. Throughout, we use the Big Bad Wolf as a metaphor for the wild, untamed, and sometimes intense power of nature (and also of unmedicated birth), and ask, what does the Big Bad Wolf have to teach us about how we support and perform childbirth today?
... It will take an epic paradigm shift to ensure that the care all laboring people supports the normal physiology of birth and women's emotional and psychological needs. UHDVA and obstetric racism especially re-confirm the absolute need for RARTRW care-the right amount at the right time and in the right way (Cheyney and Davis-Floyd 2020a), where the 'right way' refers to care that explicitly respects the rights and dignity of all birthing people (Cheyney and Davis-Floyd 2020a; Cheyney and Peters 2019). Racism underlies BIPOC pregnant people's vulnerability to UHDVA and also helps to explain health systems' failures to enact necessary reforms. ...
'Medical iatrogenesis' was first defined by Illich as injuries 'done to patients by ineffective, unsafe, and erroneous treatments'. Following Lokumage's original usage of the term, this paper explores 'obstetric iatrogenesis' along a spectrum ranging from unintentional harm (UH) to overt disrespect, violence, and abuse (DVA), employing the acronym 'UHDVA' for this spectrum. This paper draws attention to the systemic maltreatment rooted in the technocratic model of birth, which includes UH normalized forms of mistreatment that childbearers and providers may not recognize as abusive. Equally, this paper assesses how obstetric iatrogenesis disproportionately impacts Black, Indigenous, and People of Color (BIPOC), contributing to worse perinatal outcomes for BIPOC childbearers. Much of the work on 'obstetric violence' that documents the most detrimental end of the UHDVA spectrum has focused on low-to-middle income countries in Latin America and the Caribbean. Based on a dataset of 62 interviews and on our personal observations, this paper shows that significant UHDVA also occurs in the high-income U.S., provide concrete examples, and suggest humanistic solutions.
Background and Objectives
Selective pressures on human childbirth have led to the evolution of cooperative birth practices, with birth attendants playing a crucial role in providing emotional support during labor.
Methodology
We leveraged COVID-19-related healthcare disruptions to investigate the impact of the evolutionary mismatch in availability of emotional support persons on perceived birth stress among a US-based convenience sample (N = 1082).
Results
Individuals who stated during pregnancy that they desired support from their partner or a doula but who did not receive this support had significantly higher perceived childbirth stress (B = 12.5, p < 0.0001; and B = 5.2, p = 0.02, respectively, measured on a scale of 0-100). The absence of any support persons (B = 6.7, p < 0.001), the number of emotional support persons present (B = -5.8 for each additional support person, p = 0.01), and feeling that the healthcare provider was busy or distracted during labor (B = 15, p < 0.001) was significantly associated with childbirth stress. Virtual support did not attenuate these effects.
Conclusions and Implications
Not being able to have desired emotional support during labor was associated with significantly higher childbirth stress, even after adjusting for clinical childbirth complications. These effect sizes were substantial, comparable to the elevated stress associated with cesarean section delivery and other childbirth complications. These findings underscore the importance of preventing an evolutionary mismatch in emotional needs during labor by ensuring access to continuous support, even during public health emergencies.
Pregnancy and childbirth are almost universally associated with culturally based ceremonies and rituals. Although the importance of giving birth in a healthcare facility is recognized among the Giriama community, many mothers continue to give birth in the village with traditional midwives. This ethnographic study explored the cultural context and practices of birthing among the indigenous Giriama of Kenya and how such practices may affect maternal and neonatal outcomes. DESIGN: We utilized qualitative interviews and focus group discussions. Study participants included 40 mothers and 5 traditional birth attendants (TBAs) also known as the traditional midwives. RESULTS: A majority of women who were interviewed shunned hospital delivery because it did not fit their cultural beliefs on what constitutes an acceptable pregnancy journey. The study revealed cultural practices that supported women's health and well-being and cultural practices that were harmful. According to Giriama culture, for a successful delivery, expectant mothers are supposed to avoid viewing dead bodies, to abstain from intercourse, and to observe certain dietary restrictions. Wives are required to continue to give birth until they reach menopause, when their eggs are “finished.” Wives are also required to properly dispose of the placenta by burying it to ensure their future fertility. DISCUSSION: Identifying and understanding local customs, beliefs, and practices, particularly those that may be harmful to pregnant women, while leaving in place those that carry no harm, are critical to developing community-based strategies for improving maternal and neonatal health. Moreover, collaboration with the community may lead to changes in lieu of cultural practices in such a way that safety in childbirth is enhanced. There is need for awareness of the potential effects of the lack of decision-making power of women, particularly in relation to needed maternity care.
Sustainable midwifery is best realized in a model of care that promotes not only optimal health for women and families but also long-term well-being for care providers. Midwifery has been with us since the dawn of our existence, but in numerous industrialized nations and despite excellent outcomes, midwives have been marginalized by political oppression based primarily on desires for the power and revenues of childbirth. As articulated by Davis-Floyd (Davis-Floyd, Int J Gynecol Obstet 75(Suppl 1):S5–S23, 2001; Davis-Floyd, American midwifery: a brief anthropological overview. In: Davis-Floyd R, Colleagues (eds) Ways of knowing about birth: mothers, midwives, medicine, and birth activism. Waveland, Long Grove, pp 165–188, 2018b), the three models of healthcare now practiced are the technocratic, humanistic, and holistic. Each of these has a role to play in the perinatal period, but in terms of sustainability, holistic care is far superior, as within it, the patient becomes a client and primary decision-maker in her healthcare experience, with the midwife an equal partner in their interaction. The hierarchy that characterizes technocratic care, with practitioner in charge and patient essentially powerless, dissolves in holism. Medical education for hospital practice is largely based on technocratic tenets of authority and control, humanistic education may add elements of communication and kindness, but holistic education is the game changer. Tenets of holism can be used in any setting, as the time-tested skills of midwifery care are increasingly articulated and refined to meet a rising demand for this type of care.
This chapter considers a model of doula care that has the radical potential to improve maternity outcomes among some of the most marginalized women in the United States while enabling reproductive justice, employment opportunities, and community empowerment. The originators of this model trained low-income and previously incarcerated women of color in the East Bay area of San Francisco to work as birth doulas within their communities. The pilot project proved hugely successful for both the doulas and their clients, who speak eloquently of their increased awareness of birth justice, reproductive justice, and self-actualization. This model illustrated that a doula’s support can extend far beyond birth into broader issues of family, self-worth, and community health, as both doulas and their clients were able to pursue goals they had considered unreachable before the project. While the project was supported by grants, the doulas are actively working to make this model more sustainable across California by having doula work subsidized by Medicaid and funded by the savings incurred from healthy mothers and newborns needing less invasive and costly care than is presently available.
The understanding and experience of conception, pregnancy and childbirth
Cesarean section (surgical removal of a neonate through the maternal abdominal and uterine walls) can be a life-saving medical intervention for both mothers and their newborns when vaginal delivery through the birth canal is impossible or dangerous. In recent years however, the rates of cesarean sections have increased in many countries far beyond the level of 10-15% recommended as optimal by the World Health Organization. These 'excess' cesarean sections carry a number of risks to both mothers and infants including complication from surgery for the mother and respiratory and immunological problems later in life for the infants. We argue that an evolutionary perspective on human childbirth suggests that many of these 'unnecessary' cesarean sections could be avoided if we considered the emotionally supportive social context in which childbirth has taken place for hundreds of thousands or perhaps even millions of years of human evolution. The insight that human childbirth is usually a cooperative, even social event in which women are attended by familiar, supportive family and friends suggests that the harsh clinical environment in which women often give birth in the developed world is not the best setting for dealing with the strong emotional forces that usually accompany labor and delivery. We argue that providing a secure, supportive environment for laboring mothers can reduce the rate of 'unnecessary' surgical deliveries.
Objectives
The narrow human birth canal evolved in response to multiple opposing selective forces on the pelvis. These factors cannot be sufficiently disentangled in humans because of the limited range of relevant variation. Here, we outline a comparative strategy to study the evolution of human childbirth and to test existing hypotheses in primates and other mammals.
Methods
We combined a literature review with comparative analyses of neonatal and female body and brain mass, using three existing datasets. We also present images of bony pelves of a diverse sample of taxa.
Results
Bats, certain non‐human primates, seals, and most ungulates, including whales, have much larger relative neonatal masses than humans, and they all differ in their anatomical adaptations for childbirth. Bats, as a group, are particularly interesting in this context as they give birth to the relatively largest neonates, and their pelvis is highly dimorphic: Whereas males have a fused symphysis, a ligament bridges a large pubic gap in females. The resulting strong demands on the widened and vulnerable pelvic floor likely are relaxed by roosting head‐down.
Conclusions
Parturition has constituted a strong selective force in many non‐human placentals. We illustrated how the demands on pelvic morphology resulting from locomotion, pelvic floor stability, childbirth, and perhaps also erectile function in males have been traded off differently in mammals, depending on their locomotion and environment. Exploiting the power of a comparative approach, we present new hypotheses and research directions for resolving the obstetric conundrum in humans.
The human birth canal shows a tight fit with the size of the neonate, which can lead to obstetric complications. This is not the case in other apes, and has been explained as the outcome of conflicting evolutionary pressures for bipedal locomotion and parturition of a highly encephalized fetus. Despite the suggested evolutionary constraints on the female pelvis, we show that women are, in fact, extremely variable in the shape of the bony birth canal, with human populations having differently shaped pelvic canals. Neutral evolution through genetic drift and differential migration are largely responsible for the observed pattern of morphological diversity, which correlates well with neutral genetic diversity. Climatic adaptation might have played a role, albeit a minor one, with populations from colder regions showing a more transversally oval shape of the canal inlet. The significant extent of canal shape variation among women from different regions of the world has important implications for modern obstetric practice in multi-ethnic societies, as modern medical understanding has been largely developed on studies of European women.
Background:
Caesarean section prevalence is increasing in Asia and Latin America while remaining low in most African regions. Caesarean section delivery is effective for saving maternal and infant lives when they are provided for medically-indicated reasons. On the basis of ecological studies, caesarean delivery prevalence between 9% and 19% has been associated with better maternal and perinatal outcomes, such as reduced maternal land fetal mortality. However, the specific prevalence of obstetric and medical complications that require caesarean section have not been established, especially in low-income and middle-income countries (LMICs). We sought to provide information to inform the approach to the provision of caesarean section in low-resource settings.
Methods:
We did a literature review to establish the prevalence of obstetric and medical conditions for six potentially life-saving indications for which caesarean section could reduce mortality in LMICs. We then analysed a large, prospective population-based dataset from six LMICs (Argentina, Guatemala, Kenya, India, Pakistan, and Zambia) to determine the prevalence of caesarean section by indication for each site. We considered that an acceptable number of events would be between the 25th and 75th percentile of those found in the literature.
Findings:
Between Jan 1, 2010, and Dec 31, 2013, we enrolled a total of 271 855 deliveries in six LMICs (seven research sites). Caesarean section prevalence ranged from 35% (3467 of 9813 deliveries in Argentina) to 1% (303 of 16 764 deliveries in Zambia). Argentina's and Guatemala's sites all met the minimum 25th percentile for five of six indications, whereas sites in Zambia and Kenya did not reach the minimum prevalence for caesarean section for any of the indications. Across all sites, a minimum overall caesarean section of 9% was needed to meet the prevalence of the six indications in the population studied.
Interpretation:
In the site with high caesarean section prevalence, more than half of the procedures were not done for life-saving conditions, whereas the sites with low proportions of caesarean section (below 9%) had an insufficient number of caesarean procedures to cover those life-threatening causes. Attempts to establish a minimum caesarean prevalence should go together with focusing on the life-threatening causes for the mother and child. Simple methods should be developed to allow timely detection of life-threatening conditions, to explore actions that can remedy those conditions, and the timely transfer of women with those conditions to health centres that could provide adequate care for those conditions.
Funding:
Eunice Kennedy Shriver National Institute of Child Health and Human Development.
Despite decades of considerable economic investment in improving the health of families and newborns world‐wide, aspirations for maternal and newborn health have yet to be attained in many regions. The global turn toward recognizing the importance of positive experiences of pregnancy, intrapartum and postnatal care, and care in the first weeks of life, while continuing to work to minimize adverse outcomes, signals a critical change in the maternal and newborn health care conversation and research prioritization. This paper presents “different research questions” drawing on evidence presented in the 2014 Lancet Series on Midwifery and a research prioritization study conducted with the World Health Organization. The results indicated that future research investment in maternal and newborn health should be on “right care,” which is quality care that is tailored to individuals, weighs benefits and harms, is person‐centered, works across the whole continuum of care, advances equity, and is informed by evidence, including cost‐effectiveness. Three inter‐related research themes were identified: examination and implementation of models of care that enhance both well‐being and safety; investigating and optimizing physiological, psychological, and social processes in pregnancy, childbirth, and the postnatal period; and development and validation of outcome measures that capture short and longer term well‐being. New, transformative research approaches should account for the underlying social and political‐economic mechanisms that enhance or constrain the well‐being of women, newborns, families, and societies. Investment in research capacity and capability building across all settings is critical, but especially in those countries that bear the greatest burden of poor outcomes. We believe this call to action for investment in the three research priorities identified in this paper has the potential to achieve these benefits and to realize the ambitions of Sustainable Development Goal Three of good health and well‐being for all.
Background:
Cesarean sections (CS) are among the most commonly performed surgical procedures in the world. Epidemiologic data has associated delivery by CS with an increased risk of certain adverse health outcomes in children, such as asthma and obesity.
Objective:
To explore what is known about the effect of mode of delivery on the development of the infant microbiome and discuss the potentially mediating role of CS-related microbial dysbiosis in the development of adverse pediatric health outcomes. Recommendations for future inquiry are also provided.
Methods:
This study provides a narrative overview of the literature synthesizing the findings of literature retrieved from searches of PubMed and other computerized databases and authoritative texts.
Results:
Emerging evidence suggests that mode of delivery is involved in the development of the neonatal microbiome and may partially explain pediatric health outcomes associated with birth by CS. Specifically, the gut microbiome of vaginally delivered infants more closely resembles their mothers' vaginal microbiome and thus more commonly consists of potentially beneficial microbiota such as Lactobacillus, Bifidobacterium, and Bacteroides. Conversely, the microbiome of infants born via CS shows an increased prevalence of either skin flora or potentially pathogenic microbial communities such as Klebsiella, Enterococcus, and Clostridium.
Conclusions:
Mode of delivery plays an important role in the development of the postnatal microbiome but likely tells only part of the story. More comprehensive investigations into all the pre- and perinatal factors that have the potential to contribute to the neonatal microbiome are warranted.
Birth mechanics in early hominins are often reconstructed based on cephalopelvic proportions, with little attention paid to neonatal shoulders. Here, we find that neonatal biacromial breadth can be estimated from adult clavicular length (R2 = 0.80) in primates. Using this relationship and clavicular length from adult Australopithecus afarensis, we estimate biacromial breadth in neonatal australopiths. Combined with neonatal head dimensions, we reconstruct birth in A. afarensis (A.L. 288-1 or Lucy) and find that the most likely mechanism of birth in this early hominin was a semi-rotational oblique birth in which the head engaged and passed through the inlet transversely, but then rotated so that the head and shoulders remained perpendicular and progressed through the midplane and outlet oblique to the main axis of the female pelvis. Any other mechanism of birth, including asynclitic birth, would have resulted in either the head or the shoulders orthogonal to the short anteroposterior dimension of the A.L. 288-1 pelvis, making birth untenable. There is a tight fit between the infant and all planes of the birth canal, perhaps suggesting a difficult labor in australopiths. However, the rotational birth mechanism of large-brained humans today was likely not characteristic of A. afarensis. Thus, the evolution of rotational birth, usually associated with encephalization, may have occurred in two stages: the first appeared with the origin of the australopiths with their platypelloid pelves adapted for bipedalism and their broad-shouldered neonates; the second which resulted in the modern mechanism of rotational birth may be associated with increasing brain size in the genus Homo. Anat Rec, 300:890–899, 2017.
If we restrict the use of Homo sapiens in the fossil record to specimens which share a significant number of derived features in the skeleton with extant H. sapiens , the origin of our species would be placed in the African late middle Pleistocene, based on fossils such as Omo Kibish 1, Herto 1 and 2, and the Levantine material from Skhul and Qafzeh. However, genetic data suggest that we and our sister species Homo neanderthalensis shared a last common ancestor in the middle Pleistocene approximately 400–700 ka, which is at least 200 000 years earlier than the species origin indicated from the fossils already mentioned. Thus, it is likely that the African fossil record will document early members of the sapiens lineage showing only some of the derived features of late members of the lineage. On that basis, I argue that human fossils such as those from Jebel Irhoud, Florisbad, Eliye Springs and Omo Kibish 2 do represent early members of the species, but variation across the African later middle Pleistocene/early Middle Stone Age fossils shows that there was not a simple linear progression towards later sapiens morphology, and there was chronological overlap between different ‘archaic’ and ‘modern’ morphs. Even in the late Pleistocene within and outside Africa, we find H. sapiens specimens which are clearly outside the range of Holocene members of the species, showing the complexity of recent human evolution. The impact on species recognition of late Pleistocene gene flow between the lineages of modern humans, Neanderthals and Denisovans is also discussed, and finally, I reconsider the nature of the middle Pleistocene ancestor of these lineages, based on recent morphological and genetic data.
This article is part of the themed issue ‘Major transitions in human evolution’.
Nosocomial infections are also known as hospital-acquired/associated infections. National
Healthcare Safety Network along with Centers for Disease Control for surveillance has
classified nosocomial infection sites into 13 types with 50 infection sites, which are specific
on the basis of biological and clinical criteria. The agents that are usually involved in hospitalacquired
infections include Streptococcus spp., Acinetobacter spp., enterococci, Pseudomonas
aeruginosa, coagulase-negative staphylococci, Staphylococcus aureus, Bacillus cereus,
Legionella and Enterobacteriaceae family members, namely, Proteus mirablis, Klebsiella
pneumonia, Escherichia coli, Serratia marcescens. Nosocomial pathogens can be transmitted
through person to person, environment or contaminated water and food, infected individuals,
contaminated healthcare personnel’s skin or contact via shared items and surfaces. Mainly,
multi-drug-resistant nosocomial organisms include methicillin-resistant Staphylococcus aureus,
vancomycin-resistant enterococci, Pseudomonas aeruginosa and Klebsiella pneumonia,
whereas Clostridium difficile shows natural resistance. Excessive and improper use of broadspectrum
antibiotics, especially in healthcare settings, is elevating nosocomial infections, which
not only becomes a big health care problem but also causes great economic and production loss
in the community. Nosocomial infections can be controlled by measuring and comparing the
infection rates within healthcare settings and sticking to the best healthcare practices. Centers
for Disease Control and Prevention provides the methodology for surveillance of nosocomial
infections along with investigation of major outbreaks. By means of this surveillance, hospitals
can devise a strategy comprising of infection control practices.
The fossil record of the human pelvis reveals the selective priorities acting on hominin anatomy at different points in our evolutionary history, during which mechanical requirements for locomotion, childbirth and thermoregulation often conflicted. In our earliest upright ancestors, fundamental alterations of the pelvis compared with non-human primates facilitated bipedal walking. Further changes early in hominin evolution produced a platypelloid birth canal in a pelvis that was wide overall, with flaring ilia. This pelvic form was maintained over 3-4 Myr with only moderate changes in response to greater habitat diversity, changes in locomotor behaviour and increases in brain size. It was not until Homo sapiens evolved in Africa and the Middle East 200 000 years ago that the narrow anatomically modern pelvis with a more circular birth canal emerged. This major change appears to reflect selective pressures for further increases in neonatal brain size and for a narrow body shape associated with heat dissipation in warm environments. The advent of the modern birth canal, the shape and alignment of which require fetal rotation during birth, allowed the earliest members of our species to deal obstetrically with increases in encephalization while maintaining a narrow body to meet thermoregulatory demands and enhance locomotor performance.
© 2015 The Author(s) Published by the Royal Society. All rights reserved.
The pelvis performs two major functions for terrestrial mammals. It provides somewhat rigid support for muscles engaged in locomotion and, for females, it serves as the birth canal. The result for many species, and especially for encephalized primates, is an 'obstetric dilemma' whereby the neonate often has to negotiate a tight squeeze in order to be born. On top of what was probably a baseline of challenging birth, locomotor changes in the evolution of bipedalism in the human lineage resulted in an even more complex birth process. Negotiation of the bipedal pelvis requires a series of rotations, the end of which has the infant emerging from the birth canal facing the opposite direction from the mother. This pattern, strikingly different from what is typically seen in monkeys and apes, places a premium on having assistance at delivery. Recently reported observations of births in monkeys and apes are used to compare the process in human and non-human primates, highlighting similarities and differences. These include presentation (face, occiput anterior or posterior), internal and external rotation, use of the hands by mothers and infants, reliance on assistance, and the developmental state of the neonate.
© 2015 The Author(s) Published by the Royal Society. All rights reserved.
Between 2004 and 2010, the number of home births in the United States rose by 41%, increasing the need for accurate assessment of the safety of planned home birth. This study examines outcomes of planned home births in the United States between 2004 and 2009.
We calculated descriptive statistics for maternal demographics, antenatal risk profiles, procedures, and outcomes of planned home births in the Midwives Alliance of North American Statistics Project (MANA Stats) 2.0 data registry. Data were analyzed according to intended and actual place of birth.
Among 16,924 women who planned home births at the onset of labor, 89.1% gave birth at home. The majority of intrapartum transfers were for failure to progress, and only 4.5% of the total sample required oxytocin augmentation and/or epidural analgesia. The rates of spontaneous vaginal birth, assisted vaginal birth, and cesarean were 93.6%, 1.2%, and 5.2%, respectively. Of the 1054 women who attempted a vaginal birth after cesarean, 87% were successful. Low Apgar scores (< 7) occurred in 1.5% of newborns. Postpartum maternal (1.5%) and neonatal (0.9%) transfers were infrequent. The majority (86%) of newborns were exclusively breastfeeding at 6 weeks of age. Excluding lethal anomalies, the intrapartum, early neonatal, and late neonatal mortality rates were 1.30, 0.41, and 0.35 per 1000, respectively.
For this large cohort of women who planned midwife-led home births in the United States, outcomes are congruent with the best available data from population-based, observational studies that evaluated outcomes by intended place of birth and perinatal risk factors. Low-risk women in this cohort experienced high rates of physiologic birth and low rates of intervention without an increase in adverse outcomes.
Human birth follows a pattern which is unique among mammals. Distinctions include the orientation of the fetus as it passes through the birth canal, the way the fetus emerges from the birth canal, difficulty during labor, and behavior by the mother and/or other individuals around the time of birth. Birth has important implications for the morphology of the pelvis, for sex differences in the pelvis, for such aspects of human biology as size (and maturity) at birth, and for behavior (including cooperative behavior). This paper reviews the fossil and comparative evidence for when and how the modern pattern of birth evolved.
The modern human pattern of birth evolved in a mosaic manner with some unique features appearing early in human evolution and others quite late. A human-like entry of the fetal head into the birth canal was already present among australopithecines as a result of their wide pelvic apertures. Other aspects of modern human birth such as the rotation of the head and body within the birth canal and the emergence of the fetal head in an occiput anterior position probably evolved later, when encephalization had placed increasing selection on both the form of the pelvis and the timing of birth. Cooperative behavior during and after birth accompanied the origin of the fully modern human mechanism of birth.
The unique phenomenon of modern human birth did not evolve in response to a single “obstetrical dilemma” but as part of a complex interplay between changes in a number of aspects of human biology.
Paleoanthropological reconstructions of childbirth in the genus Homo typically rely upon a model incorporating the evolution of a monotypic human birth mechanism. Two features characterize this proposed mechanism or pathway taken by the fetus through the birth canal: fetal rotation and neonate emergence in a posi-tion facing away from the mother. The evolution of these two features is said to facilitate birth through the bipedal pelvis but is also taken as evidence of the difficulty of human birth relative to that in other primates and our smaller-brained ancestors. In contrast, the present work takes the position that birth mecha-nisms vary now and probably did so in the past. The notion of a monotypic birth mechanism has been imported into paleoanthro-pological discourse from typological thinking in Euro-American biomedical practice and text. The history of anatomical descrip-tions of pelvic types and associated birth mechanisms shows a trend toward the concept of a singular "normal" birth mecha-nism in biomedical practice. This paper suggests that biomedi-cally defined pelvic typologies constitute a static definition of human variation in pelvic morphology and that pelvic typology, in turn, has contributed to a static definition of the normal hu-man birth process that has been incorporated into paleoanthropo-logical models.. She has done research in computed tomographic osteometry (1993–96) and archaeologi-cal fieldwork in France (1995 and 1996). Her research interests are the biological and social implications of reproductive tech-nology, gender, and human evolution. Her publications include "Decoding the Discourses: Feminism and Science" (American Anthropologist 104:327–30) and (with M. M. Glantz) "Sexual Di-morphism in the Pelvic Midplane and Its Relationship to Nean-derthal Reproductive Patterns" (American Journal of Physical Anthropology 100:89–100). The present paper was submitted 4 ii 00 and accepted 29 iii 02.
While evolution by natural selection has long been a foundation for biomedical science, it has recently gained new power to explain many aspects of disease. This progress results largely from the disciplined application of what has been called the adaptations program. We show that this increasingly significant research paradigm can predict otherwise unsuspected facets of human biology, and that it provides new insights into the causes of medical disorders, such as those discussed below: 1. Infection. Signs and symptoms of the host-parasite contest can be categorized according to whether they represent adaptations or costs for host or parasite. Some host adaptations may have contributed to fitness in the Stone Age but are obsolete today. Others, such as fever and iron sequestration, have been incorrectly considered harmful. Pathogens, with their large populations and many generations in a single host, can evolve very rapidly. Acquisition of resistance to antibiotics is one example. Another is the recently demonstrated tendency to change virulence levels in predictable ways in response to changed conditions imposed incidentally by human activities. 2. Injuries and toxins. Mechanical injuries or stressful wear and tear are conceptually simpler than infectious diseases because they are not contests between conflicting interests. Plant-herbivore contests may often underlie chemical injury from the defensive secondary compounds of plant tissues. Nausea in pregnancy, and allergy, may be adaptations against such toxins. 3. Genetic factors. Common genetic diseases often result from genes maintained by other beneficial effects in historically normal environments. The diseases of aging are especially likely to be associated with early benefits. 4. Abnormal environments. Human biology is designed for Stone Age conditions. Modern environments may cause many diseases-for example, deficiency syndromes such as scurvy and rickets, the effects of excess consumption of normally scarce nutrients such as fat and salt, developmental diseases such as myopia, and psychological reactions to novel environments. The substantial benefits of evolutionary studies of disease will be realized only if they become central to medical curricula, an advance that may at first require the establishment of one or more research centers dedicated to the further development of Darwinian medicine.
Une etude morphologique comparative chez les singes et les humains de tete et d'epaules de nouveaux nes, compares a la taille de pelvis maternel a ete realisee. La seule etude des dimensions de la tete, pourrait laisser penser que seul les enfants humains avaient besoin de rotation prenatale pour pouvoir naitre. Cependant, la prise en compte de la taille des epaules plus larges et moins flexibles suggere que des rotations neonatales ont pu avoir ete necessaires pour les hominides les plus precoces. Ceci met en evidence que l'importance des contraintes neonatales apportees par les epaules ont peut etre ete sous-estimees.
The risk of nosocomial infection due to Staphylococcus aureus in fullterm newborns is higher under hospital conditions where there are overcrowded nurseries and inadequate infection control techniques. We report on an outbreak of skin infection in a Maternity Nursery (May 21, 2000) and the measures undertaken to bring the epidemic under control. These measures included: separating neonates already present in the nursery on August 23, 2000 from ones newly arriving by creating two different cohorts, one of neonates born before this date and one of neonates born later; restricting healthcare workers caring for S. aureus- infected infants from working with non-infected infants; disallowing carrier healthcare workers from caring for patients; introducing contact and droplet precautions (including the routine use of gowns, gloves, and mask); ensuring appropriate disinfection of potential sources of contamination. A representative number of isolates were typed by genomic DNA restriction length polymorphism analysis by means of pulsed-field gel electrophoresis (PFGE). Among the 227 cases of skin lesions, microbiological laboratory analyses confirmed that 175 were staphylococcal infections. The outbreak showed a gradual reduction in magnitude when the overcrowding of the Nursery was reduced by separating the newborns into the two different Nurseries (two cohorts). The genotyping of the strains by PFGE confirmed the nurse-to-newborn transmission of S. aureus. The measures adopted for controlling the S. aureus outbreak can, in retrospect, be assessed to have been very effective.
This book reveals how giving birth is an inherently safe, relatively painless process that is best performed without the assistance of doctors or midwives, and how confidence and a positive attitude reduces fear—and therefore the pain—of labor.
According to Laura Kaplan Shanley, a renowned leader in the natural-birth movement, human birth is inherently safe and relatively painless—provided we refrain from physical or psychological interference. The problems often associated with birth can be traced to three main factors: poverty, unnecessary medical intervention, and fear. When these causes are eliminated, most women can give birth either alone or with the help of a partner, friends, or family.
This second edition of Unassisted Childbirth leads with a history of childbirth and then describes how most deliveries occur today, detailing why these processes don't serve mothers or babies. The information in this unique book gives women yet another legitimate choice in childbirth that doesn't rely on doctors and technology, and allows parents, birth professionals, and general readers to reexamine their most basic ideas about birth and learn to think in new ways.
Evolution is the single most important idea in modern biology, shedding light on virtually every biological question, from the shape of orchid blossoms to the distribution of species across the planet. Until recently, however, the theory has had little impact on medical research or practice. Evolutionary Medicine shows how this is beginning to change. Collecting work from leaders in the field, this volume describes an array of new and innovative approaches to human health that are based on an appreciation of our long evolutionary history. For example, it shows how evolution helps to explain the complex relationship between our immune systems and the virulence and transmission of human viruses. It also shows how comparisons between how we live today and how our hunter-gatherer ancestors lived thousands of years ago illuminate a variety of contemporary ills, including obesity, lower-back pain, and insomnia. Evolutionary Medicine covers issues at every stage of life, from infancy (colic, jaundice, SIDS, parent-infant sleep struggles, ear infections, breast-feeding, asthma) to adulthood (sexually transmitted diseases, depression, overeating, addictions, child abuse, cardiovascular disease, breast and ovarian cancer) to old age (osteoporosis, geriatric sleep problems). Written for a wide range of students and researchers in medicine, anthropology, and psychology , it is an invaluable guide to this rapidly developing field.
Evolution is the single most important idea in modern biology, shedding light on virtually every biological question, from the shape of orchid blossoms to the distribution of species across the planet. Until recently, however, the theory has had little impact on medical research or practice. Evolutionary Medicine shows how this is beginning to change. Collecting work from leaders in the field, this volume describes an array of new and innovative approaches to human health that are based on an appreciation of our long evolutionary history. For example, it shows how evolution helps to explain the complex relationship between our immune systems and the virulence and transmission of human viruses. It also shows how comparisons between how we live today and how our hunter-gatherer ancestors lived thousands of years ago illuminate a variety of contemporary ills, including obesity, lower-back pain, and insomnia. Evolutionary Medicine covers issues at every stage of life, from infancy (colic, jaundice, SIDS, parent-infant sleep struggles, ear infections, breast-feeding, asthma) to adulthood (sexually transmitted diseases, depression, overeating, addictions, child abuse, cardiovascular disease, breast and ovarian cancer) to old age (osteoporosis, geriatric sleep problems). Written for a wide range of students and researchers in medicine, anthropology, and psychology , it is an invaluable guide to this rapidly developing field.
Without cesarean delivery, obstructed labor due to a disproportion of the fetus and the maternal birth canal can result in maternal and fetal injuries or even death. The precise frequency of obstructed labor is difficult to estimate because of the widespread use of cesarean delivery for indications other than proven cephalopelvic disproportion, but it has been estimated that at least one million mothers per year are affected by this disorder worldwide. Why is the fit between the fetus and the maternal pelvis so tight? Why did evolution not lead to a greater safety margin, as in other primates? Here, we review current research and suggest new hypotheses on the evolution of human childbirth and pelvic morphology. In 1960, Washburn suggested that this "obstetrical dilemma" arose because the human pelvis is an evolutionary compromise between two functions, bipedal gait and childbirth. However, recent biomechanical and kinematic studies indicate that pelvic width does not considerably affect the efficiency of bipedal gait and thus is unlikely to have constrained the evolution of a wider birth canal. Instead, bipedalism may have primarily constrained the flexibility of the pubic symphysis during pregnancy, which opens much wider in most mammals with larger fetuses than in humans. We argue that the birth canal is mainly constrained by the trade-off between two pregnancy-related functions: while a narrow pelvis is disadvantageous for childbirth, it offers better support for the weight exerted by the viscera and the large human fetus during the long gestation period. We discuss the implications of this hypothesis for understanding pelvic floor dysfunction. Furthermore, we propose that selection for a narrow pelvis has also acted in males due to the role of pelvic floor musculature in erectile function. Finally, we review the cliff-edge model of obstetric selection to explain why evolution cannot completely eliminate cephalopelvic disproportion. This model also predicts that the regular application of life-saving cesarean has evolutionary increased rates of cephalopelvic disproportion already. We address how evolutionary models contribute to understanding and decision-making in obstetrics and gynecology as well as in devising health care policies.
In the 1900s Black midwives, referred to as granny midwives, dominated the midwifery field in the United States. Over the last century their numbers drastically declined. In 2014, less than ten percent of new midwifery students entering the field were Black women. Factors attributing to the rapid reduction of Black midwives were national regulatory policies such as required licensure to practice and mandated supervision from physicians. These were promoted through public health campaigns in media and literature. The focus of this paper is to utilize critical discourse analysis (CDA) to highlight the role public discourse had in perpetuating racial biases toward Black midwives in the early 1900s, contributing to the lack of Black midwives seen today. This paper is an analysis of an internationally acclaimed public health training film, All My Babies: A Midwife’s Own Story. The objectives of this research are to: 1.) explore how the political climate and national policies shaped the discourse of the film, 2.) identify reoccurring concepts, 3.) analyze how the discourse of the film maintained or challenged the existing social structure, and 4.) provide recommendations for future public health discourse. The process for selecting the film was based on its international influence, distribution nationally, and the opportunity to analyze verbal and non-verbal discourse. The process for identifying concepts within the film was modeled from Norman Fairclough and Thomas Huckin’s framework for CDA. Public health significance of this research: It is critical to communicate public health information equitably – accurately and fairly - to prevent furthering health inequities by gender and ethnicity. The benefit to using a CDA approach is that it explores the distribution of power and how it is maintained or challenged through public health discourse. This paper will use CDA to identify power with respect to racism in discourse that is easily overlooked. Once we recognize underpinnings of racial ideologies in our work, we can create media that promotes social justice through equitable representation.
Birth attendance has been proposed as a distinguishing feature of humans (Homo sapiens) and it has been linked to the difficulty of the delivery process in our species. Here, we provide the first quantitative study based on video-recordings of the social dynamics around three births in captive bonobos (Pan paniscus), human closest living relative along with the chimpanzee. We show that the general features defining traditional birth attendance in humans can also be identified in bonobos. As in humans, birth in bonobos was a social event, where female attendants provided protection and support to the parturient until the infant was born. Moreover, bystander females helped the parturient during the expulsive phase by performing manual gestures aimed at holding the infant. Our results on bonobos question the traditional view that the “obligatory” need for assistance was the main driving force leading to sociality around birth in our species. Indeed, birth in bonobos is not hindered by physical constraints and the mother is self-sufficient in accomplishing the delivery. Although further studies are needed both in captivity and in the wild, we suggest that the similarities observed between birth attendance in bonobos and humans might be related to the high level of female gregariousness in these species. In our view, the capacity of unrelated females to form strong social bonds and cooperate could have represented the evolutionary pre-requisite for the emergence of human midwifery.
The postnatal period represents a crucial time for the developing mucosal immune system that coincides with early life colonization of the host by microbial pioneers and initial exposure to an infant's surrounding environment. Immediately after birth, opportunistic commensal communities disseminate throughout the gastrointestinal tract and fundamentally influence the maturation, instruction, and function of immune regulatory and effector subsets in order to facilitate tolerance to environmental antigens and guide the symbiotic relationship between the host and its emerging microbiome. In certain contexts, deviation from optimal host-commensal interactions during infancy can have durable and potentially deleterious consequences on the microbial training of specific immune subsets that can manifest as chronic inflammation and/or autoimmune disease in later life. Here we discuss the role of early life microbial education of the immune system during this 'window of opportunity' when the ecological succession of commensal populations has a potentially critical impact on human health and disease.
Childbirth Across Cultures explores the childbirth process through globally diverse perspectives to offer a broader context with which to think about birth. It addresses multiple rituals and management models surrounding the labor and birth process from communities across the globe.
Labor and birth are biocultural events that are managed in countless ways. We are particularly interested in the notion of power. Who controls the pregnancy and the birth? Is it the hospital, the doctor, or the in-laws, and in which cultures does the mother have the control? These decisions, regarding place of birth, position, who receives the baby and even how the mother may or may not behave during the actual delivery are all part of the different ways that birth is handled.
The cultures included range from the Solomon Islands to Africa, Asia and the Americas. Other chapters cover Midwives and other Birth Attendants, Evolution of Birth, Women’s Birth Narratives, and Child Spacing and Breastfeeding.
This book will bring together global research conducted by professional anthropologists, midwives and doctors who work closely with the individuals from the cultures they are writing about, offering a unique perspective direct from the cultural group.
Evolutionary science is critical to an understanding of integrated human biology and is increasingly recognized as a core underpinning discipline by medical and public health professionals. Advances in the fields of genomics, epigenetics, developmental biology and epidemiology have led to the growing realization that incorporating evolutionary thinking is essential for medicine to achieve its full potential. This is the first integrated and comprehensive textbook to explain the principles of evolutionary biology from a medical perspective and to focus on how medicine and public health might utilize evolutionary biology. It is written in a style which is accessible to a broad range of readers, whether or not they have had formal exposure to evolutionary science. Principles of Evolutionary Medicine is divided into three sections: the first provides a systematic approach to the principles of evolutionary biology as they apply to human health and disease, using examples specifically relevant to medicine. It incorporates chapters on evolutionary processes, molecular evolution, the evolution of humans, life history theory, and evolutionary-developmental biology. The second part illustrates the application of these principles to our understanding of nutrition and metabolism, reproduction, combatting infectious disease and stress, and human behaviour. The final section provides a general framework to show in practical terms how the principles of evolutionary medicine can be applied in medical practice and public health.
This book places childbirth in early-modern England within a wider network of social institutions and relationships. Starting with illegitimacy - the violation of the marital norm - it proceeds through marriage to the wider gender-order and so to the 'ceremony of childbirth', the popular ritual through which women collectively controlled this, the pivotal event in their lives. Focussing on the seventeenth century, but ranging from the sixteenth to the eighteenth century, this study offers a new viewpoint on such themes as the patriarchal family, the significance of illegitimacy, and the structuring of gender-relations in the period.
Because of the implications for behavioral, social, and cultural evolution, reconstructions of the evolutionary history of human parturition are driven by two main questions: First, when did childbirth become difficult? And second, does difficult childbirth have something to do with infant helplessness? Here we review the available evidence and consider answers to these questions. Although the definitive timeframe remains unclear, childbirth may not have reached our present state of difficulty until fairly recently (<500,000 years ago) when body and brain sizes approximated what we have now, or perhaps not until even more recently because of agriculture's direct and indirect effects on the growth and development of both mother and fetus. At present, there is little evidence to indicate that difficult childbirth has affected the evolution of gestation length or fetal growth, selecting for infants that are born in a supposed underdeveloped state, although these phenomena likely share causes.
Is as sensitive as conventional cytology, and has other advantages
Cervical screening has been shown to reduce the incidence of cervical cancer, but only in the setting of well organised, high quality programmes. In the United Kingdom the NHS cervical screening programme has been estimated to prevent around 80% of deaths from cervical cancer.1
Liquid based cytology represents the first major change in preparation method for cervical screening samples for over 50 years. Instead of cells being smeared onto a glass slide, they are washed into a vial of liquid and filtered, and a random sample is presented in a thin layer on a glass slide. These slides can then either be screened by skilled staff or subjected to partially automated imaging. The process is being widely used in the United States, many European countries, and elsewhere.
In this week's BMJ two studies compare the accuracy of liquid based cytology with conventional cytology.2 3 The randomised trial by Ronco and colleagues found no significant difference in sensitivity for cervical intraepithelial neoplasia of grade 2 or more with liquid based cytology using ThinPrep (Cytyc, Boxborough, MA, USA) compared with conventional cytology.2 However, more positive …
▪ Abstract This chapter reviews what is presently known about the sudden infant death syndrome (SIDS) and examines the role that infant sleeping arrangements may play in reducing SIDS risks. Alongside sleep laboratory-based experimental evidence comparing bedsharing and solitary sleeping mother-infant pairs, an evolutionary and cross-cultural framework is used to argue that infant-parent cosleeping is biologically, psychologically, and socially the most appropriate context for the development of healthy infant sleep physiology. It is also the context within which potentially more optimal breastfeeding activities for both the mother and infant are most likely to emerge. A survey of cross-cultural data and laboratory findings suggest that where infant-parent cosleeping and breastfeeding are practiced in tandem in nonsmoking households, and are practiced by parents specifically to promote infant health, the chances of an infant dying from SIDS should be reduced.
Why do so many American women allow themselves to become enmeshed in the standardized routines of technocratic childbirth—routines that can be insensitive, unnecessary, and even unhealthy? This book is a second edition of the text. The new preface in this edition makes it clear that the issues surrounding childbirth remain as controversial as ever. The book analyzes the technocratic method of birth, its cultural variations and alternatives, and obstetric training and women's experiences in Western culture. It covers ritual and how it is used in obstetrics, and compares the technocratic and holistic paradigms of childbirth. The book demonstrates the linkages between American core values concerning technology and expertise, and prevailing obstetrical practices.
In 1967 the Kibish Formation in southern Ethiopia yielded hominid cranial remains identified as early anatomically modern humans, assigned to Homo sapiens
1, 2, 3, 4. However, the provenance and age of the fossils have been much debated5, 6. Here we confirm that the Omo I and Omo II hominid fossils are from similar stratigraphic levels in Member I of the Kibish Formation, despite the view that Omo I is more modern in appearance than Omo II1, 2, 3. 40Ar/39Ar ages on feldspar crystals from pumice clasts within a tuff in Member I below the hominid levels place an older limit of 198 14 kyr (weighted mean age 196 2 kyr) on the hominids. A younger age limit of 104 7 kyr is provided by feldspars from pumice clasts in a Member III tuff. Geological evidence indicates rapid deposition of each member of the Kibish Formation. Isotopic ages on the Kibish Formation correspond to ages of Mediterranean sapropels, which reflect increased flow of the Nile River, and necessarily increased flow of the Omo River. Thus the 40Ar/39Ar age measurements, together with the sapropel correlations, indicate that the hominid fossils have an age close to the older limit. Our preferred estimate of the age of the Kibish hominids is 195 5 kyr, making them the earliest well-dated anatomically modern humans yet described.
The origin and rise of social inequalities that are a feature of the post-Neolithic society play a major role in the pattern of disease in prehistoric and contemporary populations. We use the concept of epidemiological transition to understand changing ecological relationships between humans, pathogens and other disease insults. With the Paleolithic period as a baseline, we begin with ecological and social relationships that minimized the impact of infectious disease. Paleolithic populations would have retained many of the pathogens that they shared with their primate ancestors and would have been exposed to zoonoses that they picked up as they adapted to a foraging existence. The sparse mobile populations would have precluded the existence of endemic infectious disease. About 10,000 years ago, the shift to an agricultural subsistence economy created the first epidemiological transition, marked by the emergence of infections, a pattern that has continued to the present. Beginning about a century ago, some populations have undergone a second epidemiological transition in which public health measures, improved nutrition and medicine resulted in declines in infectious disease and a rise in non-infectious, chronic and degenerative diseases. Human populations are entering the third epidemiological transition in which there is a reemergence of infectious diseases previously thought to be under control, and the emergence of novel diseases. Many of the emerging and reemerging pathogens are antibiotic resistant and some are multi-antibiotic resistant. Inequality continues to widen within and between societies, accelerating the spread of emerging and reemerging diseases.