Seminars in Perinatology

Published by WB Saunders
Online ISSN: 0146-0005
Publications
Article
Apnea of prematurity is common and none of the treatments being used are fully effective and free of significant adverse side effects. We hypothesized that low concentrations of CO2 (< or = 1.5%) may reduce apnea without causing discomfort from an increase in ventilation. We studied 10 preterm infants at a gestational age of 32+/-1 wk (mean +/- SEM) and birthweight 1.8+/-0.2 kg. After a control period of 1 hour, concentrations of CO2 were given (0.5%, 1%, and 1.5%) for 1 hour each, followed by a recovery period of 1 hour. Apnea number significantly decreased from 2.0+/-0.3 apneas/min during control to 1.0+/-0.1 apneas/min (0.5% CO2; P < .05), 1.1+/-0.2 (1% CO2; P < .05), and to 0.7+/-0.2 (1.5% CO2; P < .01). The apnea time significantly decreased from 14.2+/-2.5 s/min during control to 5.2+/-0.8 (0.5% CO2; P < .01), 5.8+/-0.7 (1% CO2; P < .01), and to 3.7+/-0.9 (1.5% CO2; P < .01). Minute ventilation significantly increased with CO2 without evidence of respiratory discomfort. TcPCO2 did not change and TcPO2 increased slightly. These findings suggest that inhalation of low concentrations of CO2 in preterm infants with apnea 1) decreases the number and time of apneas, 2) improves oxygenation, 3) increases ventilation, and 4) is effective even in such low concentrations as 0.5%. We speculate that inhalation of CO2 (< 1%) is more effective and safer than methylxanthines for the treatment of apnea of prematurity.
 
Article
This article reviews the role of ductus venosus (DV) Doppler evaluation in the screening for aneuploidies at 11 to 14 weeks of gestation. Ductus venosus flow velocity waveforms were obtained immediately before fetal karyotyping in 515 consecutive singleton pregnancies at 11 to 14 weeks. We found 446 normal and 69 abnormal karyotypes. Abnormal flow in the DV was the only significant difference between both groups. Sensitivity of the test was 80% and false positive rate < 1%. Normal karyotype but abnormal flow in the DV was recorded in 17 of 446 cases, 7 presenting a cardiac defect. Increased nuchal translucency seems to be related, in most cases, to early cardiac dysfunction. Chromosomal abnormalities and/or cardiac defects were often found in cases with increased nuchal translucency and abnormal flow in the DV. We suggest that the evaluation of ductal flow between 11 to 14 weeks of gestation should be adopted as a second level screening test to reduce invasive test rate derived from the exclusive measurement of nuchal translucency.
 
Article
The effects of nicotine are seen in every trimester of pregnancy, from increased spontaneous abortions in the first trimester, to increased premature delivery rates and decreased birth weights in the final trimester. The birth weight of a baby is dependent on two factors: the gestational age of the fetus at the time of delivery and the rate of fetal growth. Nicotine has been shown to affect both of these factors. Carbon monoxide, also found in tobacco, forms carboxyhemoglobin, which inhibits the release of oxygen into fetal tissues. Nicotine readily gains access to the fetal compartment via the placenta, with fetal concentrations generally 15% higher than maternal levels. The primary metabolite of nicotine, cotinine, has a half-life of 15 to 20 hours and serum concentrations that are 10-fold higher than nicotine; thus, cotinine provides a better index of nicotine exposure because of its longer half-life. Nicotine concentrates in fetal blood, amniotic fluid, and breastmilk. The fetus and neonate may also have environmental tobacco exposure that may be significant. In animal models and humans, nicotine increases maternal blood pressure and heart rate, with a concomitant reduction in uterine blood flow. An increase in fetal heart rate is also seen, which is thought to be caused by catecholamine release. The impact of nicotine on the respiratory and central nervous system is also reviewed. In conclusion, the physiological effect of tobacco on fetal growth seems to be a culmination of both the vasoconstrictive effects of nicotine on the uterine and potentially the umbilical artery and the effects on oxygenation by carboxyhemoglobin.
 
Article
The survival prospects for infants of birthweight less than or equal to 1500 g born in recent years have improved. Evidence for a corresponding decrease in long-term morbidity of survivors is conflicting but recent reports from some centers indicate that high morbidity rates are occurring. Until additional satisfactory reports are available on the outcome of very low birthweight (VLBW) infants born after 1975, preferably from a community or region, uncertainty will continue. The outcome of three cohorts of VLBW infants, born in the Royal Women's Hospital, Melbourne between 1966 and 1978 is reported; more than 90% of each cohort were fully assessed, aged 2-8 years. There were 169 long-term survivors from the first cohort (1966-1970 births) and 72 from the second cohort (1973-74 births); survival rates were 37.1% and 37.3% respectively; however, for the 1977-78 births, there were 161 survivors, a significant increase to 68.3%. In the first cohort, 32.7% had one or more visual defects and 3.9% were blind but visual morbidity decreased progressively in cohorts 2 and 3; 3% of the second cohort and 1.2% of the third cohort were blind. There was a trend for a decrease in severe sensorineural deafness. Cerebral palsy increased progressively, respectively 2.6%, 4.5% and 11.9% in the first, second and third cohorts. There was a significant increase in the mean Mental Developmental Index of the Bayley Scales at the age of 2 years from 75.38 for the 64 children born in 1966-70 compared with 90.96 for 150 children in the 1977-78 cohort. Although there had been an increase in upper social class families in the more recent cohort, improvement in test scores was still highly significant when higher social classes (1-3 Congalton Scale) were excluded. However, there was no significant improvement in the 6 year psychological test scores of the first and second cohorts. There was a steady increase in occurrence of cerebral palsy. Significance associations in the 1977-78 cohort were found with only 2 perinatal variables (use of theophylline and necrotizing entercolitis). Furthermore, 17 (89.5%) of children had a five-minute Apgar score greater than 5 and 14 (73.7%) did not require ventilatory support: Prevention of cerebral palsy by selective treatment in the delivery room or nursery was not feasible for prediction of this condition was not possible from perinatal risk factors.
 
Article
Each year over 75,000 pregnant women in the United States undergo nonobstetric surgery. The operations include those directly related to pregnancy, such as cerclage, those indirectly related to pregnancy, such as ovarian cystectomy, and those unrelated to gestation, such as appendectomy. When a pregnant woman presents for surgery, it is a stressful event for everyone involved. Issues about the surgical problem itself often seem secondary to maternal (and physician) concerns about the effect of surgery and anesthesia on the developing fetus, or the potential to trigger preterm labor. This article reviews the physiologic and anatomic changes that affect anesthetic care during pregnancy. The author also reviews the effects of anesthetic drugs and perioperative events on the fetus and on the pregnancy outcome. The relatively small number of published series are reviewed as well as the controversial recommendations regarding fetal and maternal monitoring during surgery.
 
Article
A risk index based on a variety of reproductive, perinatal and environmental variables was used to attempt to predict the developmental outcome of very low birthweight infants (birthweights under 1501 grams). Forty-one preterm infants and a demographically matched group of 42 fullterm infants were studied. The McCarthy Scales of Children's Abilities was administered to the children at 5 years of age. In general, the preterm children were delayed in the perceptual, memory, and motor abilities in comparison with the fullterm children. There were no significant differences between the AGA (appropriate for gestational age) and SGA (small for gestational age) preterm groups. Multiple regression and discriminant function measures were used to examine the overall relationship between the earlier measures and later development and to assess the risk for an individual child. The risk index was able to account for typically 30-40% of the variance associated with the 5 year scores and the prediction of an individual child's development was accurate for approximately 85% of the time. Severity of illness during the perinatal period, independently of social class and infant tests scores were the best predictors of outcome. This study demonstrates that developmental outcome can be predicted with a high degree of accuracy and a relatively simple system.
 
Article
There are contraceptive methods available to the adolescent, and a knowledgeable clinician can help the patient choose the best method available for the individual. In this discussion of alternatives to adolescent pregnancy, attention is directed to the following: a historical overview of pregnancy prevention and management of sexually transmitted diseases; oral contraceptives; contraindications of oral contraceptive (OC) use (cardiovascular/cardiopulmonary conditions, migraine headaches, epilepsy, oligomenorrhea, sickle cell disease, the liver, cancer, and miscellaneous side-effects); the low-estrogen OC, the mini-pill; IUDs; barrier methods; postcoital contraceptives; injectable contraceptives; abstinence; periodic abstinence; and miscellaneous methods. Although the OC continues to be the most popular method among teenagers who use an effective method, the clinican needs to emphasize the safety and efficacy of barrier methods for the motivated teenager. The clinical also needs to remember that understanding of these issues of adolescent contraception and pregnancy is rooted in the very process of adolescence itself. The health care professional should remember that he/she is providing information for the teenage patient for only part of her reproductive years. A method selected by the patient at a particular time in her life may be replaced later by other methods as she matures. The health care professional provides the information and counsel; the patient chooses for herself.
 
Article
We examined trends in fetal growth among singleton live births in the United States and Canada. The data files (n = 48,637,680; 16.6% blacks) for US births, and the Canadian Birth Database of Statistics Canada (n = 3,167,702) for Canadian births were used. Trends were assessed between 1985-86 and 1997-98 with reference to mean birthweight, birthweight-for-gestational-age z-score, and proportions delivered low birthweight (< 2,500 g), small for gestational age (SGA: birthweight < 10th centile for gestational age) and large for gestational age (LGA: birthweight > 90th centile). The term "mean birth weight" increased in the US and Canada between 1985 and 1998, as have the mean z-score. Rates of term SGA births declined among US (11% among whites and 12% among blacks) and Canadian births (27%). Preterm SGA births increased by 3% and 17%, respectively, among US whites and blacks, but declined by 11% among Canadian births. Further, term LGA births increased in the US (5% among whites and 9% among blacks) and Canada (24%). Preterm LGA births declined by 13%, 25%, and 14% among US whites and blacks, and Canadian births, respectively. These findings suggest that US and Canadian babies are getting bigger. The role of preterm obstetrical induction and preterm cesarean delivery are likely to have influenced these trends.
 
Article
There is mounting evidence that infants born late preterm (34-36 weeks) are at greater risk for morbidity than term infants. This article examines the changing epidemiology of gestational length among singleton births in the United States, from 1992 to 2002. Analyzing gestational age by mode of delivery, the distribution of spontaneous births shifted to the left, with 39 weeks becoming the most common length of gestation in 2002, compared with 40 weeks in 1992 (P < 0.001). Deliveries at > or =40 weeks gestation markedly decreased, accompanied by an increase in those at 34 to 39 weeks (P < 0.001). Singleton births with PROM or medical interventions had similar trends. Changes in the distribution of all singleton births differed by race/ethnicity, with non-Hispanic white infants having the largest increase in late preterm births. These observations, in addition to emerging evidence of increased morbidity, suggest the need for investigation of optimal obstetric and neonatal management of these late preterm infants.
 
Article
We analyzed US fetal death and linked infant birth-death certificate data for 1995-1998 to evaluate perinatal deaths (late fetal deaths [> or = 28 weeks' gestation] and early neonatal deaths [< or = 7 days of life]) by race, Hispanic ethnicity, state of residence, and selected demographic characteristics. We also compared components of perinatal mortality, late fetal deaths, and early neonatal deaths, by birthweight, gestational age, and selected maternal medical conditions during pregnancy. From 1995 through 1998, there were 221,767 fetal deaths at > or = 20 weeks' gestation and infant deaths at less than 1 year. Of these, 113,421 (51%) were perinatal deaths; late fetal deaths accounted for 47% of perinatal deaths. The total perinatal mortality rate declined 5.3%, from 7.5 to 7.1 per 1,000 live births plus late fetal deaths. Blacks experienced higher perinatal mortality rates than whites (rate ratio = 2.1). Among perinatal deaths > or = 28 weeks' gestation, the ratio of fetal to neonatal deaths was 3.4 among blacks and 2.4 among whites. State-specific rates ranged from 5.2 to 13.1 per 1,000 live births plus late fetal deaths. Although late fetal deaths are not included in routine statistics of pregnancy outcomes, these deaths represent a large proportion of adverse pregnancy outcomes. Surveillance of perinatal mortality provides a more complete picture of the health of women, fetuses, and newborns. Improving the quality of surveillance data regarding fetal deaths is essential for more effective use of these data. This information can be used to prevent excess perinatal deaths and reduce disparities in pregnancy outcomes among high-risk subgroups identified by individual and population characteristics.
 
Article
Kernicterus in sick and preterm infants is a rarity. Universal availability of phototherapy and concerted clinical efforts to identify, effectively manage and establish clinical guidelines have been instrumental in preventing kernicterus in US intensive care nurseries. However, in sick and preterm infants the absence of precise data on prevalence of bilirubin induced neurologic injury, the lack of proven predictive indices and the absence of evidence-based studies that clearly demonstrate the actual risk of kernicterus. These leave questions regarding the basis for clinical strategies and recommendations for the management of neonatal jaundice in this select population. This article reviews 6 preterm infants selected from the Pilot Kernicterus Registry who had recovered from life-threatening neonatal illnesses, briefly discusses current indices used to ascertain risk, and offers an initial bilirubin level based identification of infants while future directions and studies are conducted to supplement our presently incomplete knowledge for safer clinical practice.
 
Article
Pulmonary inflammation, increased production of the inflammatory cytokine interleukin-1beta (IL-1beta), and vitamin A deficiency are risk factors for the development of bronchopulmonary dysplasia (BPD) in premature infants. To determine the mechanisms by which IL-1beta influences lung development, we have generated transgenic mice in which human IL-1beta is expressed in the lung epithelium with a doxycycline-inducible system controlled by the Clara cell secretory protein promoter. Perinatal IL-1beta production in these mice causes a phenotype that is strikingly similar to BPD. Pulmonary pathology in the mice shows inflammation, lack of alveolar septation, and impaired vascular development of the lung, similar to the histological characteristics of BPD. Retinoic acid (RA), one of the most biologically active derivatives of vitamin A, increases septation. Proteins involved in mediating the cellular responses to RA include the cellular retinoic acid binding proteins CRABP-I and CRABP-II and the nuclear retinoic acid receptors RAR-alpha, RAR-beta, and RAR-gamma. To test the hypothesis that IL-1beta inhibits the expression of proteins involved in mediating the cellular response to RA. The mRNA expression of CRABP-I, CRABP-II, RAR-alpha1, RAR-beta2, RAR-beta4, and RAR-gamma2 was studied with real-time RT-PCR on gestational day 18, and postnatal days 0, 1, 5, and 7 in IL-1beta-expressing mice and their control littermates. In addition, immunohistochemistry for CRABP-I was performed. IL-1beta decreased the mRNA expression and protein production of CRABP-I as well as the mRNA expression of RAR-gamma2. In contrast, no differences between IL-1beta-expressing and control mice were detected in the expression of CRABP-II, RAR-alpha1, RAR-beta2, or RAR-beta4. The present study demonstrates for the first time a link between inflammation and the retinoic acid pathway. Inhibition of CRABP-I and RAR-gamma2 expression may be one mechanism by which inflammation prevents alveolar septation. The therapeutic potential of RA in promoting septation in the setting of perinatal lung inflammation deserves further investigation.
 
Article
Since its beginnings in 1989, the Extracorporeal Life Support Organization (ELSO) Registry has collated and reported data on over 30,000 patients. The majority of patients entered into the Registry have been neonates with respiratory failure from meconium aspiration, persistent pulmonary hypertension, or congenital diaphragmatic hernia. These patients suffer from refractory hypoxemia; thus, this supportive technique came to be called "Extracorporeal Membrane Oxygenation (ECMO)" for its ability to provide excellent gas exchange. With advances in prevention, diagnosis, and treatment measures for neonatal respiratory failure, need for ECMO support has fallen from the peak of 1500 cases in the early 1990s to 800 cases annually. Sixty-six percent (over 19,000) of patients in the Registry are under the category of neonatal respiratory failure, with a 77% overall survival reported to discharge. The success of neonatal ECMO has led to expansion of the field to pediatric, cardiac, and adult patients. An average of 200 pediatric patients receive ECMO for respiratory failure per year with an overall survival of 55%. Adult respiratory failure patients form a smaller group, with less than 100 cases reported to the ELSO registry per year. Survival mirrors that noted in the pediatric ECMO population. The application of ECMO or related techniques continues to increase for cardiac failure across all age groups. Overall survival in cardiac patients ranges from 33% to 43%. A novel form of extracorporeal support is "ECPR" or ECMO during cardiac arrest. Bypass circuits and equipment can be set up and instituted within a very short period of time in this circumstance, thus the name "rapid deployment ECMO" has become associated with this form of support. Overall survival in the near-600 patients placed on ECMO during resuscitation is 40%.
 
Article
A 6-year (2004-2009) review of maternal deaths is presented to establish particular trends at the eastern regional hospital (1 of 10 regional hospitals in Ghana). There were a total of 191 maternal deaths over the period, with a total of 19,965 live births, giving a maternal mortality ratio of 957 per 100,000 live births. The main causes of maternal deaths were postpartum hemorrhage (22.5%), abortion-related causes (19.3%), hypertensive disorders in pregnancy (17.8%), and puerperal sepsis (8.9%). The study revealed that the highest number of deaths was recorded in the period following termination of pregnancy (abortion or delivery). Timely referral of patients to this hospital could help reduce preventable maternal deaths.
 
Article
Amniocentesis and Chorionic Villus Sampling have been the two most common prenatal diagnostic procedures for decades. There are wide variations in utilization, operator skills, quoted procedure risks, actual observed risks, and patient choices that come from highly variable counseling as to those risks. The compilation of published data suggests procedure risks of amniocentesis to be about 1/200 and in very skilled hands to be slightly lower. The risks of CVS in very experienced hands may also be about 1/200. Most studies comparing CVS to amniocentesis in skilled hands have found equivalency of risks. No well controlled studies support claims of amniocentesis risk at 1/1000 or lower. There is no increased risks of limb reduction defects following CVS at 10 weeks or greater, but there is an increase in Talipes from "Early Amniocentesis." In the first trimester CVS is the safer procedure.
 
Article
Objective: We identify the clinical implications of the ethics of informed consent for risk assessment for trisomy 21. Finding: Based on the ethics of informed consent, we find that routinely offering first-trimester risk assessment in centers qualified to provide it is ethically obligatory, and routinely withholding the results of first-trimester risk assessment is ethically unjustified. Conclusion: The ethics of informed consent is an essential dimension of first-trimester risk assessment for trisomy 21.
 
Article
This review discusses the development of melatonin rhythmicity in humans and the factors that may alter the appearance of melatonin rhythms. The literature on the possible consequences of disordered melatonin production in relation to Sudden Infant Death Syndrome, fetal origins of adult disease, and scoliosis is critically reviewed. Finally, the emerging use of melatonin to correct sleep disorders in infants and children is reviewed.
 
Article
The objective of this study was to compare the outcomes at 5 years of age of SGA and AGA children born < 28 weeks of gestation. The method used was a longitudinal follow-up of a cohort of 37 dyads of SGA and AGA infants matched by gestational age (GA), gender, and date of delivery. Mean GA was 26+/-1.2 weeks, and BW was 638+/-77 g for SGA and 833+/-134 g for AGA (P < 0.0001). The SGA infants remained lighter at 3, 24, and 60 months. Their head circumference was statistically smaller at 3 and 60 months, and their length remained lower but no longer statistically significant. There was no difference after the second year of life between SGA and AGA children in the need for rehospitalization (16% versus 11%) and the incidence of medical problems such as Otitis (38% versus 41%) and asthma (24% versus 30%). SGA exhibited more neurodevelopmental deficits (41% versus 30%) and severe handicaps, including CP, blindness, deafness, and mental retardation (22% versus 14%). Those deficits were seen predominantly in association with microcephaly, which was more prevalent in the SGA group. We conclude that the combination of severe prematurity and intrauterine growth retardation constitutes a serious developmental handicap and predisposes to physical and developmental delays. The presence of microcephaly further aggravates the prognosis.
 
Article
Each year 3.6 million infants are estimated to die in the first 4 weeks of life (neonatal period)--but the majority continue to die at home, uncounted. This article reviews progress for newborn health globally, with a focus on the countries in which most deaths occur--what data do we have to guide accelerated efforts? All regions are advancing, but the level of decrease in neonatal mortality differs by region, country, and within countries. Progress also differs by the main causes of neonatal death. Three major causes of neonatal deaths (infections, complications of preterm birth, and intrapartum-related neonatal deaths or "birth asphyxia") account for more than 80% of all neonatal deaths globally. The most rapid reductions have been made in reducing neonatal tetanus, and there has been apparent progress towards reducing neonatal infections. Limited, if any, reduction has been made in reducing global deaths from preterm birth and for intrapartum-related neonatal deaths. High-impact, feasible interventions to address these 3 causes are summarized in this article, along with estimates of potential for lives saved. A major gap is reaching mothers and babies at birth and in the early postnatal period. There are promising community-based service delivery models that have been tested mainly in research studies in Asia that are now being adapted and evaluated at scale and also being tested through a network of African implementation research trials. To meet Millennium Development Goal 4, more can and must be done to address neonatal deaths. A critical step is improving the quantity, quality and use of data to select and implement the most effective interventions and strengthen existing programs, especially at district level.
 
Article
Late preterm infants (34-37 weeks postmenstrual age at birth) are intermediate between less mature preterm infants and infants born at 38 weeks or more in regard to autonomic brain stem maturation. Ventilatory responses to CO(2) in preterm infants born at 33 to 36 week are significantly higher than in infants born at 29 to 32 weeks both at 3 to 4 and 10 to 14 days postnatal age, but do not differ from full-term reference levels. The ventilatory response to hypoxia in preterm infants is biphasic; initial transient hyperventilation is followed by a return to baseline and then a decrease below baseline. In infants born at 32 to 37 weeks, parasympathetic maturation appears significantly less than in full-term infants based on diminished increases in high frequency heart rate variability in quiet sleep, suggesting that late preterm infants are still more susceptible to bradycardia than full-term infants. Both the presence and severity of apnea of prematurity progressively decrease the higher the postmenstrual age. Late preterm infants, however, are still at risk, with prevalence rates as high as 10% compared with about 60% in infants born at <1500 g. The incidence of apparent life-threatening events is more common in preterm infants (8-10%) than full-term infants (1% or less). In the Collaborative Home Infant Monitoring Evaluation studies, the frequency of conventional and extreme events in near term infants is intermediate between preterm infants <34 weeks at birth and full-term infants. The relative risk for at least one extreme event in late preterm infants is increased (5.6 and 7.6, respectively, P < 0.008) compared with full-term infants and remains higher until 43 weeks postmenstrual age. The rate for Sudden Infant Death Syndrome in preterm infants born at 33 to 36 weeks is 1.37/1000 live births compared with 0.69 in infants born full term. Affected late preterm infants die at a older mean postmenstrual age compared with less mature infants (48 and 46 weeks, respectively), but die at a younger postmenstrual age than full-term infants (53 weeks, P < 0.05).
 
Article
Newborns who are 35 to 36 weeks gestation comprise 7.0% of all live births and 58.3% of all premature infants in the United States. They have been studied much less than very low birth weight infants. To examine available data permitting quantification of short-term hospital outcomes among infants born at 35 and 36 weeks gestation. Review of existing published data and, where possible, re-analysis of existing databases or retrospective cohort analyses. Multiple hospitals and neonatal intensive care units in the United States and England. Premature infant cohorts with infants whose dates of birth ranged from 1/1/98 through 6/30/04. 1) Death, 2) respiratory distress requiring some degree of in-hospital respiratory support during the birth hospitalization, and 3) rehospitalization following discharge home after the birth hospitalization. Newborns born at 35 and 36 weeks gestation experienced considerable mortality and morbidity. Approximately 8% required supplemental oxygen support for at least 1 hour, almost 3 times the rate found in infants born at > or =37 weeks. Among 35 to 36 week newborns who progressed to respiratory failure and who survived to 6 hours of age and did not have major congenital anomalies, the mortality rate was 0.8%. Following discharge from the birth hospitalization, 35 to 36 week infants were much more likely to be rehospitalized than term infants, and this increase was evident both within 14 days as well as within 15 to 182 days after discharge. In addition, late preterm infants experienced multiple therapies, few of which have been formally evaluated for safety or efficacy in this gestational age group. Greater attention needs to be paid to the management of late preterm infants. In addition, it is important to conduct formal evaluations of the therapies and follow-up strategies employed in caring for these infants.
 
Article
The purpose of this analysis was to determine the impact on specific forms of neonatal morbidity and mortality by allowing women to opt for delivery by elective cesarean section at 39 weeks of gestation (EGA). According to the National Vital Statistics Reports, over 70% of deliveries in the U.S. annually are at gestational ages>or=39 weeks EGA. Estimating that over 4 million deliveries occur annually in the United States, this would yield approximately 3 million pregnancies wherein the woman may exercise her choice for either primary or repeat cesarean section at 39 weeks EGA or at the point when labor is established. A search was conducted using Ovid Medline spanning the past 10 years using the following key words: fetal trauma, shoulder dystocia, brachial plexus palsy, neonatal skull fracture, obstetrical trauma, traumatic delivery, intrauterine fetal demise, stillbirth, fetal demise, and neonatal encephalopathy. Using this search technique, over 2100 articles were identified. The abstracts were reviewed and pertinent articles were chosen for further consideration. The identified articles and their applicable references were obtained for inclusion in this review. Preference was given to publications on or after the year 2000 with the exception of classical or sentinel articles, which were included without regard to year of publication. Four major categories of neonatal morbidity and mortality are discussed: Shoulder dystocia: Accepting that we do not have a successful method for the prediction or prevention of shoulder dystocia, the question becomes, "What is the chance that a baby will sustain a permanent brachial plexus injury at delivery?" Additionally, is there a significant protective effect of cesarean section in reducing the risk of such injury? Currently, the occurrence rate of brachial plexus palsy at the time of vaginal delivery ranges from 0.047% to 0.6% and for cesarean section from 0.0042% to 0.095%. Using a composite estimate of the risk of 0.15% for vaginal deliveries and applying it to the 3 million deliveries>or=39 weeks EGA, approximately 4500 cases of brachial plexus palsy would occur. If only 15% of these injuries were permanent, 675 permanent brachial plexus palsies would occur annually. If the risk of permanent injury is 1 in 10,000 as reported by Chauhan, 300 permanent brachial plexus palsies would occur annually in the United States. The range then for permanent brachial plexus injury that could be avoided with cesarean section on request would appear to vary between 1 in 5000 and 1 in 10,000 vaginal births. Fetal trauma: The incidence of significant birth trauma varies from 0.2 to 1 to 2 per 1000 births. The use of sequential instruments, for example, vacuum followed by forceps or vice versa, is specifically associated with an unacceptably high injury rate. Intrapartum-related neonatal deaths of vertex singleton fetuses with birthweights>2500 g from traumatic cranial or cervical spine injury secondary to vacuum- or forceps-assisted vaginal delivery are still occurring. Overall, the frequency of significant fetal injury is significantly greater with vaginal delivery, especially operative vaginal delivery, than with cesarean section for the nonlaboring woman at 39 weeks EGA or near term when early labor has been established. Neonatal encephalopathy: The prevalence of moderate to severe neonatal encephalopathy is 3.8/1000 term live births with a neonatal fatality rate of 9.1%. In 4% to 10% of cases, the etiology appears to be pure intrapartum hypoxia. Intrapartum hypoxia superimposed on antepartum risk factors may account for up to 25% of the moderate to severe encephalopathies, according to one cohort. A paradox in the data thus far is that infants born to nonlaboring women delivered by cesarean section had an 83% reduction in the occurrence of moderate or severe encephalopathy. Considering a prevalence of moderate or severe neonatal encephalopathy of 0.38% and applying it to the 3 million deliveries occurring at >or=39 weeks EGA in the United States annually, 11,400 cases of moderate to severe encephalopathy would occur. The rate of encephalopathy observed in infants delivered by cesarean section would yield approximately 1938 cases. This net difference in moderate to severe encephalopathy would represent 9462 cases annually in the United States that could be prevented with elective cesarean section. Although cesarean delivery may be protective for the development of neonatal encephalopathy, to date it has not proven to be protective of long-term neurologic injury in the form of cerebral palsy with or without mental retardation and/or seizure disorders. Intrauterine fetal demise: Copper reported that the rate of stillbirth is consistent from 23 to 40 weeks EGA with about 5% of all stillbirths occurring at each week of gestation. Yudkin reported a rate of 0.6 stillbirths per 1000 live births from 33 to 39 weeks EGA. After 39 weeks EGA, a significant increase in the stillbirth rate was reported (1.9 per 1000 live births). Fretts reported on fetal deaths per 1000 live births from 37 to 41 weeks of gestational age, showing that the rate progressively increased from 1.3 to 4.6 with each week of gestation. It can be estimated that delivery at 39 weeks EGA would prevent 2 fetal deaths per 1000 living fetuses. This would translate into the prevention of as many as 6000 intrauterine fetal demises in the United States annually-an impact that far exceeds any other strategy implemented for stillbirth reduction thus far. It is reasonable to inform the pregnant woman of the risk of each of the above categories, in addition to counseling her regarding the potential risks of a cesarean section for the current and any subsequent pregnancies. The clinician's role should be to provide the best evidence-based counseling possible to the pregnant woman and to respect her autonomy and decision-making capabilities when considering route of delivery.
 
Article
The experiential learning process involves participation in key experiences and analysis of those experiences. In health care, these experiences can occur through high-fidelity simulation or in the actual clinical setting. The most important component of this process is the postexperience analysis or debriefing. During the debriefing, individuals must reflect upon the experience, identify the mental models that led to behaviors or cognitive processes, and then build or enhance new mental models to be used in future experiences. On the basis of adult learning theory, the Kolb Experiential Learning Cycle, and the Learning Outcomes Model, we structured a framework for facilitators of debriefings entitled "the 3D Model of Debriefing: Defusing, Discovering, and Deepening." It incorporates common phases prevalent in the debriefing literature, including description of and reactions to the experience, analysis of behaviors, and application or synthesis of new knowledge into clinical practice. It can be used to enhance learning after real or simulated events.
 
Article
Transvaginal sonographic approach to the fetal brain, which provides detailed information about the fetal intracranial morphology, opened a new field in medicine, "neurosonography." The clinical significance of 3D ultrasound for prenatal diagnosis has been discussed since three-dimensional ultrasound was introduced in obstetrics. Three-dimensional ultrasound has several functions: surface reconstruction, multiplanar image analysis, three-dimensional sono-angiography, and volume calculation. In this article, we introduce transvaginal three-dimensional ultrasound for the assessment of fetal head and brain. Surface mode shows not only fetal head abnormality such as acrania but also normal cranial bones and sutures in the first trimester. Rotation of the brain volume image and multiplanar analysis enable tomographic visualization as magnetic resonance imaging. Sono-angiography shows the brain circulation three-dimensionally and extracted volume images of target organ provide information on detailed intracranial conditions. The technology is easy, noninvasive, and reproducible methods, and produces comprehensible and objective information.
 
Article
Forceps delivery remains an important part of the obstetric armamentarium. When applied by practitioners skilled in their use, forceps delivery can quickly and safely deliver a fetus at risk. Unfortunately, forceps can also be an instrument of harm for the women or her infant. This is particularly true of rotational forceps. The goal of this monograph is to review in detail the indications, contraindications, technique, as well as risks and complications of forceps delivery, with particular attention to rotational forceps. We conclude by asking the question: Should rotational forceps be abandoned altogether?
 
Histopathology and electron microscopy of ABCA3-deficient lung tissue. (A) A representative panel of autopsy lung tissue from an infant homozygous for a splicing mutation, demonstrating marked interstitial thickening, prominent alveolar macrophages, and areas with granular proteinaceous material. (B) An electron micrograph from the same patient, demonstrating within the alveolar type II cell the small, dense lamellar bodies with eccentrically placed electron-dense inclusions characteristic of ABCA3 deficiency (arrows). (Color version of figure is available online.) 
Article
ABCA3 is a member of the ATP Binding Cassette family of proteins, transporters that hydrolyze ATP in order to move substrates across biological membranes. Mutations in the gene encoding ABCA3 have been found in children with severe neonatal respiratory disease and older children with some forms of interstitial lung disease. This review summarizes current knowledge concerning clinical, genetic, and pathologic features of the lung disease associated with mutations in the ABCA3 gene, and also briefly reviews some other forms of childhood interstitial lung diseases that have their antecedents in the neonatal period and may also have a genetic basis.
 
Article
Prenatal ultrasound has advanced our understanding of congenital abdominal wall defects. In addition to providing insights into the divergent embryological origins and natural history of abdominal wall defects, ultrasound has had an important impact on the management of these anomalies. For fetuses with gastroschisis, the changes in appearance of the bowel may suggest expeditious delivery. In cases of omphalocele, the presence of additional anomalies is significantly associated with the ultimate prognosis for these fetuses. Giant omphalocele may preclude vaginal delivery secondary to dystocia. Exstrophies of the cloaca and bladder are rare congenital abnormalities that often present complex management issues, including gender reassignment in cases of cloacal exstrophy, for those couples wishing to continue the pregnancy. We believe that the optimal management of a fetus diagnosed with an abdominal wall defect requires a coordinated effort among specialists from maternal fetal medicine, pediatric surgery, and pediatrics.
 
Article
Mechanical vibration of the abdominal wall results in a frequency-related distribution of intra-abdominal sound pressure levels. A greater attenuation of applied signals of equal dynamic force occurs as frequency increases. A broad resonance peak exists between 6 and 18 Hz. Transducers fixed to the fetal head show clear increases in acceleration levels during stimulation of the abdominal surface with the artificial electronic larynx. Sine-wave stimulation results in a frequency-dependent increase in vibration levels of the abdominal wall of 4% to 140% of the input levels. At the fetal head, a broad peak in response was noted between 6 and 12 Hz, but the overall levels never exceeded 4% of the input level.
 
Article
Preterm birth is associated with an increased risk of visual impairment. However, not all visual deficits can be fully explained by the typical prematurity morbidity factors. In addition, children born preterm often exhibit transient hypothroxinemia of prematurity (THOP) due to premature severing of the maternal supply of thyroid hormones. Because thyroid hormone is critically needed for multiple facets of early brain development, including the structures needed for visual processing, and because the maternal thyroid supply is essential throughout pregnancy, it is possible that THOP contributes to the visual impairments seen in preterm children. To test this hypothesis, we used both clinical tests and visual-evoked potential techniques to assess visual abilities in two cohorts of preterm infants whose thyroid hormone levels were measured in the perinatal period. In the first cohort born 30 to 35 weeks gestation, we found associations between low thyroid hormone levels and reduced visual attention at 3 months corrected age (Study 1) and poor visuomotor abilities at 12 and 18 months corrected age (Study 2). In the second cohort born 23 to 35 weeks gestation, THOP severity was negatively correlated with attention at 3 months corrected age (Study 3) and contrast sensitivity and color vision at 6 months corrected age (Study 4). These findings therefore suggest that thyroid hormone is necessary for the development of early visual abilities and that THOP may partially explain the visual deficits of preterm infants.
 
Article
Bile acids (BAs) facilitate emulsification, absorption, and transport of fats and sterols in the intestine and liver and are essential for normal digestion. However, accumulation of BAs in the intestine can result in damage to the intestinal epithelium. Using the neonatal rat model of necrotizing enterocolitis (NEC), we have recently shown that BAs accumulate in both the ileal lumen and enterocytes of neonatal rats with NEC and the increased BA levels are positively correlated with disease severity. Importantly, when BAs are not allowed to accumulate, neonatal rat pups develop significantly less disease. In addition, BA transporters are altered during disease development. These data indicate that BAs play an important role in the development of experimental NEC, and suggest that the inability of neonatal rats to adequately regulate BA transporters may be a mechanism by which ileal damage occurs.
 
Article
Although the physiological function of prolactin is still unknown, the ability to measure it routinely in human blood has enabled diagnosis of hyperprolactinemic states and the early detection of tumors of the pituitary lactotrophs. The introduction of bromocriptine into medical practice revolutionized the treatment of hyperprolactineric states due to prolactinomas which are benign, very slow growing tumors that do not require active treatment unless they cause neurological and/or visual symptoms. Women with prolactinomas can be safely treated with bromocriptine. Ovulation is restored in over 80% of cases and a 70-80% pregnancy rate is achieved. In the great majority of cases (98%) pregnancy is uneventful. In 2-5% of women with prolactinomas, visual or neurological symptoms may appear during pregnancy due to pituitary enlargement. These symptoms can be treated conservatively by bromocriptine and, if needed, corticosteroids. If visual symptoms progress rapidly, surgical decompression of the pituitary fossa can be carried out safetly during pregnancy. The metabolic effects of prolactin on the fetus are still unknown. There are suggestions that prolactin may enhance fetal lung maturity and affect the growth of the fetal adrenal, however, the evidence for these actions is still far from complete.
 
Article
Abnormal placentation poses a diagnostic and treatment challenge for all providers caring for pregnant women. As one of the leading causes of postpartum hemorrhage, abnormal placentation involves the attachment of placental villi directly to the myometrium with potentially deeper invasion into the uterine wall or surrounding organs. Surgical procedures that disrupt the integrity of uterus, including cesarean section, dilatation and curettage, and myomectomy, have been implicated as key risk factors for placenta accreta. The diagnosis is typically made by gray-scale ultrasound and confirmed with magnetic resonance imaging, which may better delineate the extent of placental invasion. It is critical to make the diagnosis before delivery because preoperative planning can significantly decrease blood loss and avoid substantial morbidity associated with placenta accreta. Aggressive management of hemorrhage through the use of uterotonics, fluid resuscitation, blood products, planned hysterectomy, and surgical hemostatic agents can be life-saving for these patients. Conservative management, including the use of uterine and placental preservation and subsequent methotrexate therapy or pelvic artery embolization, may be considered when a focal accreta is suspected; however, surgical management remains the current standard of care.
 
Article
Liver disease in pregnancy may present in a subtle or dramatic fashion. An approach using the pattern of liver function abnormalities, time of gestation, and constellation of symptoms will narrow the diagnostic possibilities. Diagnostic tests, including serology, ultrasonography of the hepatobiliary tree, and liver biopsy, can make a definitive diagnosis.
 
Top-cited authors
Karthika Anand
Rebecca B. Russell
  • March of Dimes Foundation
Joann Petrini
  • Danbury Hospital
Karla Damus
  • Boston University
Siobhan M Dolan
  • Montefiore Medical Center