Children conceived by in vitro fertilisation after fresh embryo transfer

AIMS: To compare the outcome in in vitro fertilisation (IVF) children (after fresh embryo transfer) from multiple and singleton births with one another, and with normally conceived control children. METHODS: A cohort of 278 children (150 singletons, 100 twins, 24 triplets and four quadruplets), conceived by IVF after three fresh embryos had been transferred, born between October 1984 and December 1991, and 278 normally conceived control children (all singletons), were followed up for four years after birth. They were assessed for neonatal conditions, minor congenital anomalies, major congenital malformations, cerebral palsy and other disabilities. Control children, all born at term, were matched for age, sex and social class. RESULTS: The ratio of male:female births was 1.03. Forty six per cent of IVF children were from multiple births; 34.9% were from preterm deliveries; and 43.2% weighed less than 2500 g at birth. The IVF singletons were on average born one week earlier than the controls, weighed 400 g less, and had a threefold greater chance of being born by caesarean section. The higher percentage of preterm deliveries was largely due to multiple births and they contributed to neonatal conditions in 45.0% of all IVF children. The types of congenital abnormalities varied: 3.6% of IVF children and 2.5% of controls had minor congenital anomalies, and 2.5% of IVF children and none of the controls had major congenital malformations. The numbers of each specific type of congenital abnormality were small and were not significantly related to multiple births. IVF children (2.1%) and 0.4% of the controls had mild/moderate disabilities. They were all from multiple births, including two children with cerebral palsy who were triplets. CONCLUSIONS: The outcome of IVF treatment leading to multiple births is less satisfactory than that in singletons because of neonatal conditions associated with preterm delivery and disabilities in later childhood. A reduction of multiple pregnancies by limiting the transfer of embryos to two instead of three remains a high priority.     

Perinatal outcome of pregnancies after assisted reproduction: a case-control study

PURPOSE: A matched case-control study of all pregnancies obtained after either IVF or ICSI was conducted to investigate the perinatal outcome. METHODS: Three hundred eleven singleton and 115 twin pregnancies obtained after assisted reproduction were studied. Controls were selected from a regional register and were matched for maternal age, parity, singleton or twin pregnancy, and date of delivery. RESULTS: No significant difference was observed for gestational age at delivery, birth weight, incidence of congenital anomalies, and incidence of perinatal mortality between ART (singleton and twin) pregnancies and spontaneous controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies (52 vs 42%; P < 0.05) and needed more neonatal intensive care (47 vs 26%; P < 0.05). CONCLUSIONS: From this case-control study it is concluded that the perinatal outcome of ART singleton pregnancies is not different from that in matched controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies and needed more neonatal intensive care.     

Efficiency of computed tomography in diagnosis of silicotuberculosis

Seventy-five newborns from multiple pregnancies with very low and extremely low birth weight are studied. 94% of the infants under 1000 g and 66% of those above 1000 g are born by vaginal way. Intrapartal asphyxia develop most often the second twins with birth weight under 1000 g--64.7%. These are the infants with higher morbidity: RDS--56.5%, IVH--100%. The survival rate of the twins of this group is notably lower than that of the infants from singleton pregnancies with equal weight and gestational age: 12.1% under 1000 g and 69% above 1000 g, against 38.3% and 77.9% respectively.     

Neonatal morbidity and mortality associated with triplet pregnancy

OBJECTIVE: To compare neonatal morbidity and mortality in a large cohort of triplet pregnancies with singleton and twin neonates managed at a single tertiary center over a short time. METHODS: Records from all triplet pregnancies managed and delivered from 1992 to 1996 were reviewed for neonatal outcome data. Pregnancies delivered before 20 weeks' gestation and neonates with lethal congenital anomalies were excluded. The comparison group comprised all singleton and twin neonates managed in the same neonatal intensive care unit (NICU) during the same period. RESULTS: During the 5-year period, 55 triplet pregnancies and their resulting 165 neonates were managed and delivered at this center. Their outcomes were compared with those of 959 singleton and 357 twin neonates born at similar gestational ages. The median gestational age at delivery for triplets was 32.1 weeks, and 149 of the 165 infants were admitted. Sixteen triplet neonates were not admitted to our neonatal intensive care unit, 12 because of previable gestational age, three because of stillbirth, and one because of a lethal congenital anomaly. The crude perinatal mortality rate in triplets was 121 per 1000 births, and there was no significant difference in outcome based on triplet birth order. There were no significant differences in survival rates between singleton, twin, and triplet neonates, with an overall neonatal survival of 95%, 95%, and 97%, respectively. The only significant differences in morbidity were an increased incidence of mild intraventricular hemorrhage (relative risk [RR] 6.20; 95% confidence interval [CI] 2.64, 14.61), mild retinopathy of prematurity (RR 20.05; 95% CI 3.59, 111.79), and severe retinopathy of prematurity (RR 46.69; 95% CI 6.25, 348.85) in triplets compared with singletons, and severe retinopathy of prematurity (RR 6.83; 95% CI 1.24, 37.56) in triplets compared with twins. CONCLUSION: When stratified by gestational age, triplet neonates delivered at 24-34 weeks' gestation have similar outcomes as singleton and twin neonates, with the only clinically significant difference being an increased incidence of retinopathy of prematurity in triplets.     

The effect of maternal smoking on birth weight in twin pregnancies

Information on 869 076 singletons and 17 566 twins, born during the period 1983-1991, was obtained from the Swedish Medical Birth Registry. Data on birth weight, gestational duration, vital status, and maternal smoking habits during pregnancy were analyzed in order to investigate whether twinning potentiates the effect of maternal smoking on birth weight and perinatal mortality. The individual birth weights were expressed as percentages of mean birth weight, where mean birth weights of singletons and twins were calculated separately. The birth weight reducing effect of maternal smoking was found to be of the same magnitude among twins and singletons weighing > 90% of mean birth weight. For infants weighing < 90% of mean birth weight, maternal smoking had a significantly stronger effect on birth weight among singletons than among twins. When gestational duration was taken into consideration, this difference was less pronounced. The effect of maternal smoking on gestational duration was stronger among singletons than twins. The smoking-related risk increase of perinatal death was of about the same magnitude among twins and singletons.     

Risks of subsequent pregnancies on mother and newborn in female heart transplant recipients

BACKGROUND: Female heart transplant recipients are able to carry pregnancies successfully. This study evaluates the effect of subsequent pregnancies on newborn and maternal outcomes and graft survival. METHODS: Subjects were identified through a previously reported multicenter study, case reports from literature review, and recipients entered in the National Transplantation Pregnancy Registry. A retrospective analysis was completed of 35 heart transplant recipients with first pregnancies (FP) and 12 who had one or two additional pregnancies (P>1). Newborns were assessed for gestational age, neonatal birth weight, and complications. Maternal data included pregnancy outcome, peripartum complications, including infection and rejection, current graft function, and recipient survival. RESULTS: Forty-seven pregnancies (35 FP and 12 P>1) from 35 heart transplant recipients were studied. FP outcomes included 26 live births (one set of twins), four miscarriages, and six therapeutic abortions, whereas P>1 outcomes included 11 live births (one set of twins), and two miscarriages. There was no significant difference between mean birth weights (2353+/-986 gm vs 2588+/-521 g, P>1 vs FP; mean+/-SD; p=NS) or prematurity incidence (<37 weeks; 50% vs 40%; p=NS) for the live-born infants. Compared with the FP group, there was a trend toward increased neonatal complications in P>1 (40% vs 12%; p=NS). Complications were significantly more common in premature newborns compared with full-term newborns (33% vs 5%; p < 0.05). No structural malformations were identified in the live-born infants. Maternal complication rates were the same in both groups (40%). Of 28 recipients available for follow-up, the maternal survival rate was 75% for the FP group and 89% for the P> group. Mean rejection rate per year was slightly increased after pregnancy in the P>1 group. Surviving recipients had similar graft function by echocardiographic left ventricular ejection fraction. CONCLUSIONS: Post-heart transplantation pregnancies often have successful outcomes, but there is a high incidence of prematurity and low birth weight. Subsequent pregnancies do not seem to significantly increase the incidence of complications in either the newborn or mother or increase graft rejection or failure. Larger studies of posttransplantation pregnancies may provide more definitive information.     

Significance of idiopathic preterm birth in relation to previous and future pregnancies

This registry-based cohort study aimed to describe the relationship between pregnancy complications in the first and second pregnancy, focussing on idiopathic and indicated preterm birth of singleton infants in either pregnancy. The cohort consisted of all women living in Denmark with a first singleton birth in 1982 and a second in the period 1982-1987 (13,967 women). The risk of a second preterm birth was not significantly different between women who had an idiopathic or an indicated first preterm birth (15.2 and 12.8% respectively). Adjustment by logistic regression analysis for other risk factors for preterm birth did not influence the relative risk (6.0 before 32 weeks and 4.8 between 32 and 36 weeks) of a second preterm birth subsequent to a first one. Women with idiopathic preterm delivery in their first or second pregnancies give birth to infants with lower birth weight in previous or subsequent pregnancies. Emergency cesarean section in a first term pregnancy was a risk factor for subsequent idiopathic preterm birth.     

Prospective follow-up study of 423 children born after intracytoplasmic sperm injection

In order to evaluate the safety of the intracytoplasmic sperm injection (ICSI) procedure, a prospective follow-up study of 423 children born after ICSI was carried out. The aim of this study was to compile data on karyotypes, congenital malformations, growth parameters and developmental milestones. Before starting the infertility treatment, couples were asked to participate in a follow-up study including genetic counselling and prenatal diagnosis. The follow-up study of the child was based on a visit to the paediatrician-geneticist at birth or at 2 months of age, at 1 year and at 2 years of age when a physical examination for major and minor malformations and a psychomotoric evaluation were done. Between April 1991 and September 1994, 320 pregnancies obtained after ICSI led to the birth of 423 children (222 singletons, 186 twins and 15 triplets). Prenatal diagnosis determined a total of 293 karyotypes, one of which was abnormal (0.3%), and four were benign familial structural aberrations, all inherited from the paternal side. A total of 14 (3.3%) major malformations were observed, defined as those causing functional impairment or requiring surgical correlation. Neurological or developmental problems at the age of 2 months were found in 14 children, four of whom were multiples. Compared to most registers of children born after assisted reproduction and to registers of malformations in the general population, the figure of 3.3% major malformations is within the expected range. Before drawing any firm conclusion, further careful evaluations of the available data are necessary.     

Nitroglycerin and ventricular performance. Differential effect in the presence of reversible and irreversible asynergy

During the five-year period 1964-68 96 733 births were registered in the 28 hospitals equipped with maternity facilities in the Uppsala hospital region. Of these babies, 1 636 were born in 818 twin deliveries. Data on gestational age, sex, weight and length at birth, birth order, hospital type, congenital malformations and perinatal mortality are analysed. Altogether 17.3 per 1 000 of the children born during this period were born in multiple births. The perinatal mortality for the twin babies was 64 per 1 000 born, with the mortality higher in the less specialized hospitals than the others. Twin no. 1 suffered perinatal death in 67 cases per 1 000 and twin no. 2 in 60 cases per 1 000. For twins of primiparae the losses were 92 per 1 000 children and for twins born to multiparae 51 per 1 000. Altogether 72 per 1 000 male twins died perinatally compared to 52 per 1 000 female twins. The most heavy losses occurred among the low-weight premature twins and in these cases both twins often suffered perinatal death.     

Prognostic significance of prior preterm twin delivery on subsequent singleton pregnancy

OBJECTIVE: Our purpose was to determine whether preterm birth of twins is associated with an increased risk of preterm birth in a subsequent singleton pregnancy. STUDY DESIGN: The Medical University of South Carolina perinatal database was accessed to identify a cohort of patients who were delivered of twins followed by a singleton gestation (1981 to 1993). Maternal transports were excluded to minimize referral bias. Preterm birth was defined as < 37 weeks' gestation. Relative risks with 95% confidence intervals were calculated. RESULTS: One hundred forty-four patients were identified who were delivered of twins followed by a singleton gestation. Preterm delivery occurred in 86 (59.7%) of the twins and 21 (14.6%) of the subsequent singletons. Preterm birth of twins was associated with a significantly increased risk of preterm delivery in a subsequent singleton pregnancy (relative risk 2.87, 95% confidence interval 1.02 to 8.09). In the subset of women who were delivered of twins at < 30 weeks' gestation, 42% of the subsequent singletons were delivered preterm (relative risk 6.11, 95% confidence interval 2.07 to 18.02). The relative risk of preterm birth of a singleton after delivery of twins between 30 and 34 weeks' gestation was 3.63 (95% confidence interval 1.02 to 12.92). However, if the preceding twins delivered between 34 and 37 weeks' gestation, the relative risk of preterm birth of the subsequent singleton was not significantly increased (relative risk 1.42, 95% confidence interval 0.40 to 5.01). CONCLUSIONS: Preterm birth of twins before 34 weeks' gestation is associated with a significant risk for preterm delivery in a subsequent singleton pregnancy. The magnitude of risk increases with decreasing gestational age of the preceding twin delivery.     

Birthweight-specific trends in perinatal mortality by hospital category in South Australia, 1985-1990

OBJECTIVE: To investigate differences by birthweight in risk of perinatal death between level 3 hospitals (which provide care for high risk pregnancies and neonatal intensive care) and other hospitals in South Australia, using perinatal data for the 1985-1990 period. DESIGN: Analysis of birthweight-specific trends in risk of perinatal death by hospital category for singleton births, adjusting for risk factors. SUBJECTS: 114 725 singleton births of at least 400 g birthweight (or at least 20 weeks' gestation) born in hospitals in the 1985-1990 period and notified to the perinatal data collection. MAIN OUTCOME MEASURE: The relative odds of a perinatal death, as opposed to a live birth which survived the neonatal period. RESULTS: Births at level 3 hospitals had a higher crude risk of perinatal death than those at other hospitals, but this was due to the higher frequency of low birthweights at level 3 hospitals. For birthweights under 2000 g, and especially for the very low birth-weights, there was a higher risk at non-level-3 than level 3 hospitals. There was also the unexpected finding that births at level 3 hospitals in the 2500-2999 g range had a comparatively high risk of perinatal death. There was little difference in risk for births of higher birthweight. CONCLUSIONS: The greatly reduced risk of perinatal death in level 3 hospitals for babies with birthweights under 2000 g seems likely to be due to the specialist services in these hospitals. Further investigation is required to determine why babies in the 2500-2999 g range of birthweights had a comparatively high risk of perinatal death at these hospitals. This appears to be due, at least in part, to an excess contribution of deaths from congenital abnormalities. Also, it seems that the higher prevalence of complications in pregnancy in level 3 hospitals, and the transfers for induction of labour after intrauterine fetal death, would have made a contribution. These same factors may also have affected the risk in level 3 hospitals for higher birthweight births.     

Identification of multiprotein complexes containing DNA replication factors by native immunoblotting of HeLa cell protein preparations with T-antigen-dependent SV40 DNA replication activity

Adequate prenatal care has been linked to improved birth outcomes in general populations but has not been assessed in HIV-infected women. We examined longitudinal claims files and vital statistics records for women in the New York State Medicaid HIV/AIDS data base delivering a singleton from 1985 through 1990. Adequacy of the self-reported number of prenatal visits was assessed by the Kessner index. In logistics models, we estimated the association of prenatal care, illicit drug use, and other maternal characteristics with three outcomes; low birth weight, preterm birth, and small-for-gestational-age. Of 2,254 singletons delivered by this HIV-infected cohort, 28% were low birth weight, 23% were preterm birth, and 20% were small for gestational age. Two-thirds had inadequate prenatal care. Non-drug users had 57 and 26% lower adjusted odds of low birth weight and preterm delivery than drug users. The adjusted odds of low birth weight and preterm birth for women with an adequate number of prenatal visits were, respectively, 48 and 21% lower than for women with inadequate care. Adequate prenatal care was also associated with a 43% reduction in the odds of small-for-gestational-age. An adequate number of prenatal visits by women in this HIV cohort was associated with a significant reduction in all three adverse birth outcomes, but most had inadequate prenatal care. These data support strengthening efforts to bring pregnant, HIV-infected women into care.     

Regulatory sequences required for hst-1 expression in embryonal carcinoma cells

OBJECTIVE: To examine the relationship of subfertility with miscarriage, low birth weight, and preterm delivery. DESIGN: Comparison of time to pregnancy distributions between pregnancies that had different outcomes. Three comparisons were made: (a) miscarriages with live births; within live births, (b) low birth weight infant (up to 2,500 grams) or not low birth weight; (c) preterm birth (37 weeks or less) or not preterm. Cox regression was used to adjust for covariates. POPULATION: All first pregnancies were analyzed from the National Child Development Study, a large survey of young adults aged 33 years, which is nationally representative of the British-born population. MAIN OUTCOME MEASURES: The distribution of the time taken to conceive (time to pregnancy), miscarriage, birth weight, and preterm delivery. RESULTS: Pregnancies that ended in miscarriage tended to take 23% longer to conceive, after adjustment for the other variables. Pregnancies that resulted in preterm delivery tended to take 15% longer to conceive. There was no statistically significant association with low birth weight. CONCLUSIONS: Delay in time to conception is a risk factor for poor obstetric outcome, irrespective of medical intervention.     

Accuracy of ultrasound estimation of fetal weight in multiple pregnancies

Our objective was to assess the accuracy of ultrasonographic estimation of fetal weight in twins and triplets as compared to singleton pregnancies. Retrospective analysis was undertaken of ultrasound data of all fetuses who underwent an examination within 1 week of delivery (singletons 1832, twins 518, triplets 51). At birth weights below 2500 g, there was a significant overestimation of fetal weight in twins as compared to singletons, but the accuracy of the estimate was the same, except in twins between 1500 and 2499 g, when the weight was based on abdominal circumference and femur length alone. At birth weights of more than 2500 g, no difference was detected between twins and singletons. At all birth weights below 2500 g, the accuracy of weight estimation in triplets was equal to that in singletons and there were no triplets above this weight. We conclude that ultrasonographic estimation of fetal weight is as accurate in twins and triplets as it is in singletons.     

Does excessive adenosine 5''-triphosphate formation in cells lead to malignancy? A hypothesis on cancer

PROBLEM: Neonatal outcome of in vitro fertilization (IVF) pregnancies has been described by different authors, but several issues have yet to be resolved. The aim of the present study was to evaluate neonates conceived in vitro and to direct special attention to neonatal morbidity and prevalence of minor abnormalities. The information that has been accumulated so far is scant. METHOD: The first 100 babies conceived in vitro, and subsequently born in our institute, were investigated and compared with the general, spontaneously conceived newborn population. All infants were examined by a senior neonatologist, and the data that were recorded included gestational age at delivery, birth weight, gender, major malformations, minor congenital abnormalities, neonatal mortality, and neonatal morbidity (including asphyxia, jaundice, meconium aspiration, hypoglycemia, and hypocalcemia). RESULTS AND CONCLUSIONS: The data indicate that the IVF neonates assessed had a higher rate of low birth weight (37%), twinning (30%), and preterm birth (20%) in comparison with the general reference population (p < 0.05). However, no differences were encountered either in the rate of small for gestational age infants or the incidence of major malformations and minor abnormalities between these groups of newborns. The overall neonatal morbidity in IVF babies was found to exceed that of the general population. Nevertheless, at birth, there were no clinical pathognomonic signs typical of IVF babies, although more detailed metabolic, endocrine, and neurobehavioral studies are still required to confirm that newborns conceived in vitro do not differ from those conceived spontaneously in any of these respects.     

Does passive smoking in early pregnancy increase the risk of small-for-gestational-age infants?

OBJECTIVES: This study tested the hypothesis that women who deliver small-for-gestational-age infants are more often exposed to passive smoking at home or at work. METHODS: Among a 1-year cohort of nulliparous women in the city of Malm?, Sweden 872 (87.7%) women completed a questionnaire during their first prenatal visit. The study was carried out among women whose pregnancies resulted in a singleton live birth (n = 826), 6.7% of infants were classified as small for their gestational age. RESULTS: Passive smoking in early pregnancy was shown to double a woman's risk of delivering a small-for-gestational-age infant, independent of potential confounding factors such as age, height, weight, nationality, educational level, and the mother's own active smoking (odds ratio [OR] = 2.7). A stratified analysis indicated interactional effects of maternal smoking and passive smoking on relative small-for-gestational-age risk. CONCLUSIONS: Based on an attributable risk estimate, a considerable reduction in the incidence of small-for-gestational-age births could be reached if pregnant women were not exposed to passive smoking.     

Asphyxia of the newborn in east, central and southern Africa

Very scanty information is available in East, Central and Southern Africa on the incidence and risk factors associated with asphyxia of the newborn. A multicentre prospective study involving 4267 deliveries in eight countries was undertaken over a three month period, in maternity units of the central hospitals to determine the incidence; maternal, service and logistic risk factors for asphyxia of the newborn as determined by an abnormally low apgar score. 30% of births were by primigravida mothers, of whom 67% were teenagers. A birth by a teenager had a higher risk for low birth weight. Overall incidence of low birth weight was 13.9%. The overall incidence of asphyxia of the newborn was 22.9% while that associated with low birth weight (i.e. babies weighing less than 2500 grams) was 29.3% compared with 21.5% among the normal birth weight babies. Low birth weight contributed a large proportion of the high neonatal mortality of 15.9% compared to 1.8% for normal birth weight babies by 24 hours after birth. The mean mortality by 24 hours post delivery was 3.8%. Obstetrical complications are important risk factors for asphyxia of the newborn. Among the important risk factors are those associated with prolonged labour and intra partum accidents. The incidence of risk for asphyxia broadly was 21.3%, which is very close to the actual incidence of asphyxia of 22%. Lack of referral contributed to increased risk of asphyxia. In a significant proportion of infants, resuscitation measures taken were inappropriate. The stillbirth rate was 3.0% while the incidence of externally evident congenital malformations was 1.2%. There is urgent need to institute appropriate measures to prevent and manage asphyxia of the newborn in the region. These should include identification of the at risk mother, proper referral and management while adhering to correct established procedures. There is also need to develop appropriate and relevant technologies for perinatal and neonatal care through research undertaken in the region. It is also concluded that the co-operation and joint effort between the obstetricians, paediatricians and the nursing staff who all contributed to the collection of this data is a cost effective approach to research in perinatal health and consequently in instituting interventions.     

Preterm birth and cerebral palsy. Predictive value of pregnancy complications, mode of delivery, and Apgar scores

BACKGROUND: Preterm infants are at 8 times higher risk than term infants for pre- and perinatal brain damage, resulting in cerebral palsy. In this paper we have analysed the influence of prenatal and birth-related risk factors on cerebral palsy in preterm infants. METHODS: In a register-based study, 175 preterm singleton infants with cerebral palsy, born in 1982-86, were compared with 687 controls matched by gestational age and year of birth. RESULTS: Statistically significant higher rates in cases were found in parity > or = 3 (22% vs. 16%, p < 0.05), Cesarean section (67% vs. 56%, p < 0.01), and low Apgar scores at 1 minute (45% vs. 36%, p < 0.05). By multivariate analyses, two variables remained statistically significant: parity > or = 3 (adjusted OR = 1.53 (95% CI 1.00-2.34), p < 0.05) and Cesarean section (adjusted OR = 1.57 (95% CI 1.07-2.32), p < 0.05). CONCLUSIONS: Pregnancy complications preceding preterm birth did not imply a higher risk of cerebral palsy. Delivery by Cesarean section was a prognostic factor for developing cerebral palsy, and the predictive value of Apgar scores was highly limited.     

Changes in brain memory functions as affected by a constant magnetic field]

OBJECTIVE: The preferred route of delivery for breech presentation has been controversial. We compared the birth weight-specific neonatal mortality of vaginal births to cesarean births in singleton births with breech presentation. METHODS: A total of 371,692 singleton live births with breech presentation were selected for the study from the United States birth cohorts for the years 1989-1991. Differences in birth weight specific mortality were compared using a z-statistic for differences in proportions and by logistic regression. RESULTS: Compared to primary vaginal births, primary cesarean births had significantly lower neonatal mortality for all birth weight groups, despite increased prevalence of fetal malformations in the cesarean as compared with vaginally delivered group. This mortality difference was greatest in the first hour of life. Difference in overall neonatal (less than 28 days) mortality rate ranged from a low of 1.6-fold in the 500-749 g group (726.6 per 1000 vaginal births compared with 456.3 per 1000 cesarean births, P < .001) to as high as about three-fold in the 1250-1499 g group (232.9 per 1000 vaginal births compared to 72.5 per 1000 cesarean births, P < .001). In the group with birth weights over 2500 g, neonatal mortality in the primary vaginal births was 5.3 per 1000 and in the primary cesarean births, 3.2 per 1000 (P < .001). Similarly, repeat cesarean births had significantly lower birth weight-specific neonatal mortality, compared with vaginal births after previous cesarean. CONCLUSION: Singleton live births with breech presentation delivered by cesarean had lower birth weight-specific neonatal mortality as compared with vaginal births.