The Limit of Viability -- Neonatal Outcome of Infants Born at 22 to 25 Weeks' Gestation
Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland, United States New England Journal of Medicine
(Impact Factor: 55.87).
12/1993; 329(22):1597-601. DOI: 10.1056/NEJM199311253292201
With improved survival of preterm infants, questions have been raised about the limit of viability. To provide better information and counseling for parents of infants about to be delivered after 22 to 25 weeks' gestation, we evaluated the mortality and neonatal morbidity of preterm infants born at these gestational ages.
We studied retrospectively all 142 infants born at 22 to 25 weeks' gestation (as judged by best obstetrical estimate) from May 1988 through September 1991 in a single hospital. Mortality in the first six months, including stillbirths, and neonatal morbidity (i.e., the presence of intracranial pathologic conditions, chronic lung disease, and retinopathy of prematurity) were analyzed.
Fifty-six infants (39 percent) survived for six months. Survival improved with increasing gestational age; none of 29 infants born at 22 weeks' gestation survived, as compared with 6 of 40 (15 percent) born at 23 weeks, 19 of 34 (56 percent) born at 24 weeks, and 31 of 39 (79 percent) born at 25 weeks. There were seven stillbirths at 22 weeks' gestation and four stillbirths at 23 weeks. The more immature the infant, the higher the incidence of neonatal complications as determined by the number of days of mechanical ventilation, the length of the hospital stay, and the presence of retinopathy of prematurity, periventricular or intraventricular hemorrhage, or periventricular leukomalacia. Only 2 percent of infants born at 23 weeks' gestation survived without severe abnormalities on cranial ultrasonography, as compared with 21 percent of those born at 24 weeks and 69 percent of those born at 25 weeks.
We believe that aggressive resuscitation of infants born at 25 weeks' gestation is indicated, but not of those born at 22 weeks. Whether the occasional child who is born at 23 or 24 weeks' gestation and does well justifies the considerable mortality and morbidity of the majority is a question that should be discussed by parents, health care providers, and society.
Available from: Gerri Lasiuk
- "Although the causes of PTB are not fully understood, the short-term and long-term outcomes are well- documented in the medical literature. Preterm infants are at increased risk for a range of adverse outcomes, including retinopathy of prematurity , respiratory distress syndrome and bronchopulmonary dysplasia , brain injury , necrotizing enterocolitis , and, neonatal sepsis . Long-term sequelae include the risk for motor and sensory impairment, learning problems and neurocognitive impairment, and behavioural problems [9-14]. "
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ABSTRACT: Preterm birth (PTB) places a considerable emotional, psychological, and financial burden on parents, families, health care resources, and society as a whole. Efforts to estimate these costs have typically considered the direct medical costs of the initial hospital and outpatient follow-up care but have not considered non-financial costs associated with PTB such as adverse psychosocial and emotional effects, family disruption, strain on relationships, alterations in self-esteem, and deterioration in physical and mental health. The aim of this inquiry is to understand parents' experience of PTB to inform the design of subsequent studies of the direct and indirect cost of PTB. The study highlights the traumatic nature of having a child born preterm and discusses implications for clinical care and further research.
Through interviews and focus groups, this interpretive descriptive study explored parents' experiences of PTB. The interviews were audiotaped, transcribed, and analyzed for themes. Analysis was ongoing throughout the study and in subsequent interviews, parents were asked to reflect and elaborate on the emerging themes as they were identified.
PTB is a traumatic event that shattered parents' taken-for-granted expectations of parenthood. For parents in our study, the trauma they experienced was not related to infant characteristics (e.g., gestational age, birth weight, Apgar scores, or length of stay in the NICU), but rather to prolonged uncertainty, lack of agency, disruptions in meaning systems, and alterations in parental role expectations. Our findings help to explain why things like breast feeding, kangaroo care, and family centered practices are so meaningful to parents in the NICU. As well as helping to (re)construct their role as parents, these activities afford parents a sense of agency, thereby moderating their own helplessness.
These findings underscore the traumatic nature and resultant psychological distress related to PTB. Obstetrical and neonatal healthcare providers need to be educated about the symptoms of Acute Stress Disorder (ASD) and Posttraumatic Stress Disorder (PTSD) to better understand and support parents' efforts to adapt and to make appropriate referrals if problems develop. Longitudinal economic studies must consider the psychosocial implications of PTB to in order to determine the total related costs.
- "Babies weighing less than 1500 g have a mortality risk at least 100-fold higher than those with an optimal weight (the weight associated with the lowest mortality). Worldwide neonatal survival has improved significantly over the last four decades, particularly so in the developed countries which have witnessed an increasing survival of extremely low-birth-weight babies during this period. Our recent publications, as well as other international publications, have confirmed that State of Qatar's current neonatal survival rates and short-term morbidities are comparable with most developed world countries. "
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ABSTRACT: The study aimed to develop a national reference on birth weight-specific neonatal survival in the State of Qatar to facilitate parental counseling.
This was a retrospective, analytic, and comparative study.
The birth weight-specific neonatal mortality data for the years 2003 and 2010, collected from the admission and discharge registers of the neonatal intensive care unit, were stratified using the stratifications given in Vermont Oxford Network (VON) 2007 annual report. Category-wise birth weight-specific mortality and relative risk (RR) of death were compared between Qatar data (2003 and 2010) and VON 2007 report.
Qatar's neonatal mortality rate (NMR) dropped from 5 of 1000 in 2003 to 4.4 of 1000 in 2010 (P=0.443) which was significant for birth weight categories 501-750 g and 751-1000 g (P=0.026 and P=0.05, respectively). Qatar's NMR in 2010 was significantly lower than VON's NMR during 2007 (P<0.001) though VON's NMR was significantly lower among birth weight categories 751-1000 g and 1001-1500 g (P=0.001 and P=0.003, respectively). The RR of mortality decreased with increasing birth weight. The decline was very sharp for birth weight categories between 500 and 1500g. The RR was 25 times higher in babies with birth weight less than 750 g as compared to babies with birth weight ≥ 2550 g, both in Qatar and VON data. For birth weight categories 751-1000 g and 1001-1500 g, the RR was twice in Qatar as compared to the VON report (16.8 versus 7.8, and 5.5 versus 2.7, respectively).
Qatar's current overall and birth weight-specific NMRs are comparable with the VON report except in birth weight categories 751-1000 g and 1001-1500 g which were higher in Qatar. This needs further in-depth qualitative analysis.
Available from: Mary Elizabeth Hartnett
- "When inspired oxygen levels were reduced, ROP was virtually eliminated. Advances in neonatal care and technology have since led to increased survival of very low birthweight infants of young gestational age  and ROP has re-emerged . High oxygen at birth is now avoided in countries that have implemented the technology to monitor and regulate oxygen and thus may not be a cause of most cases of ROP . "
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ABSTRACT: To determine the effects of oxygen fluctuations on pigment epithelial-derived factor (PEDF) and vascular endothelial growth factor (VEGF)/PEDF ratios in a relevant rat model of retinopathy of prematurity (ROP).
The expression of retinal PEDF mRNA and of VEGF and PEDF protein were determined using real-time polymerase chain reaction or enzyme-linked immunosorbent assays at different postnatal day ages for rat pups raised in room air (RA) or in a rat model mimicking ROP. Statistical outcomes were determined with factorial analyses of variance. Mean VEGF and PEDF protein levels were determined at different ages for rats in the ROP model and for RA-raised rats, and the ratio of VEGF/PEDF protein versus age was plotted. At postnatal day (P) 14, inner retinal plexus vascularization had extended to the ora serrata in pups raised in RA. In the ROP model, avascular retina persisted at P14 and intravitreous neovascularization developed at P18. Therefore, VEGF and PEDF expression was determined in the ROP model and in RA-raised rat pups at P14 and P18.
Older age was associated with increased PEDF mRNA (p<0.001), PEDF protein (p=0.005), and VEGF protein (p=0.005), and VEGF protein (p<0.0001). Exposure to fluctuations of oxygen in the 50/10 oxygen-induced retinopathy model compared to RA was associated with increased PEDF mRNA (p=0.0185), PEDF protein (p<0.0001), or VEGF protein (p<0.0001). The VEGF/PEDF ratio favored angiogenic inhibition (<1.0) before but not on P14, when avascular retina persisted in the ROP model but not in RA. The VEGF/PEDF ratio favored angiogenesis (>1.0) at P14 and P 18 when intravitreous neovascularization occurred in the ROP model.
Increased expression levels of VEGF and PEDF are associated with older postnatal day age or with exposure to fluctuations in oxygen in the 50/10 oxygen-induced retinopathy model compared to RA. PEDF protein more closely associates with avascular retinal features and neovascularization than does VEGF protein or the VEGF/PEDF in the ROP model. Although PEDF has been proposed as a potential treatment in ROP, interventional studies using PEDF in an ROP model to potentially reduce intravitreous neovascularization are required to determine timing, efficacy, and dose of PEDF.
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