Perinatal mortality: Trends in prevalence and association with birth weight

To determine trends in the prevalence of congenital cerebral palsy (CP) over a 16-year period for 1-year survivors using a large, population-based surveillance program. We determined birth weight-specific trends in the prevalence of CP in live birth and 1-year survivor cohorts of children in a 5-county metropolitan Atlanta area for the periods from 1975-1977, 1981-1985, and 1986-1991. We ascertained children with CP in metropolitan Atlanta by record review as part of an ongoing developmental disability surveillance program conducted by the Centers for Disease Control and Prevention and the Georgia Department of Human Resources. A total of 110, 262, and 443 cases of congenital CP were identified for the birth years 1975-1977, 1981-1985, and 1986-1991, respectively. Data were analyzed by birth weight, race, subtypes of CP, and whether the CP existed as an isolated disability or was accompanied by another disability. There was a modest increase in the overall prevalence of congenital CP from 1.7 to 2.0 per 1000 1-year survivors during the period from 1975-1991. This trend was primarily attributable to a slight increase in CP in infants of normal birth weight--CP rates in moderately low and very low birth weight infants did not show consistent trends. There was an increase in the proportion of children who had CP and no other disabilities that was most apparent in infants of normal birth weight from 17% in 1975-1977 to 39% in 1986-1991. For children weighing <1500 g, the proportion of children with spastic diplegic CP increased over time (7% of cases in 1975-1977, 36% in 1985-1988, and 32% in 1986-1991). In the only ongoing population-based study of CP in the United States, there has been a modest increase in the prevalence of CP in 1-year survivors born from 1975-1991. This increase however was seen only in infant survivors of normal birth weight. No change was seen in the trends in CP prevalence in low birth weight and very low birth weight infant based on infant survivors.

Perinatal deaths (fetal or infant deaths from the 28th week of pregnancy up to the seventh day after birth) occur as a result of adverse conditions during pregnancy, labor, and delivery, or in the first few days of life. Placental malaria infection is known to increase the risk of delivery of a low birth weight infant, thus, potentially increasing the risk of perinatal and infant mortality. To better understand the relationship among the adverse events in pregnancy, including placental malaria infection, adverse conditions in labor, and birth weight to perinatal mortality, we investigated the perinatal mortality among a cohort of infants born to rural Malawian women for whom placental malaria infection status and birth weight were documented. Among the 2,063 mother-singleton infant pairs, there were 111 perinatal deaths (53.8 perinatal deaths per 1,000 births). The risk of perinatal death increased as birth weight decreased. Risk factors identified for perinatal mortality among all infants excluding birth weight included abnormal delivery (cesarean section, breech, or vacuum extraction), a history of a late fetal or neonatal death in the most recent previous birth among multiparous women, reactive maternal syphilis serology, nulliparity, and low socioeconomic status. Placental malaria infection was not associated with increased perinatal mortality, but was associated with lower perinatal mortality among normal birth weight (> or = 2,500 g) infants (odds ratio = 0.35, 95% confidence interval = 0.14, 0.92). Interventions to address these risk factors could have a substantial impact on reducing perinatal mortality in this population.

BackgroundAs multiple pregnancies show a higher incidence of complications than singletons and carry a higher perinatal risk, the calculation of birth weight – and gestational age (GA)-specific perinatal mortality rates (PMR) for multiple births is necessary in order to estimate the lowest PMR for these groups.MethodsDetails of all reported twins (192,987 live births, 5,539 stillbirths and 1,830 early neonatal deaths) in Japan between 1990 and 1999 were analyzed and compared with singletons (10,021,275 live births, 63,972 fetal deaths and 16,862 early neonatal deaths) in the annual report of vital statistics of Japan. The fetal death rate (FDR) and PMR were calculated for each category of birth weight at 500-gram intervals and GA at four-week intervals. The FDR according to birth weight and GA category was calculated as fetal deaths/(fetal deaths + live births) × 1000. The perinatal mortality rate (PMR) according to birth weight and GA category, was calculated as (fetal deaths + early neonatal deaths)/(fetal deaths + live births) × 1000. Within each category, the lowest FDR and PMR were assigned with a relative risk (RR) of 1.0 as a reference and all other rates within each category were compared to this lowest rate.ResultsThe overall PMR per 1,000 births for singletons was 6.9, and the lowest PMR was 1.1 for birth weight (3.5–4.0 kg) and GA (40- weeks). For twins, the overall PMR per 1,000 births was 36.8, and the lowest PMR was 3.9 for birth weight (2.5–3.0 kg) and GA (36–39 weeks). At optimal birth weight and GA, the PMR was reduced to 15.9 percent for singletons, and 10.6 percent for twins, compared to the overall PMR. The risk of perinatal mortality was greater in twins than in singletons at the same deviation from the ideal category of each plurality.ConclusionPMRs are potentially reduced by attaining the ideal birth weight and GA. More than 90 percent of mortality could be reduced by attaining the optimal GA and birth weight in twins by taking particular care to ensure appropriate pregnancy weight gain, as well as adequate control for obstetric complications.

Birth weight as a risk factor for perinatal lamb mortality, and the effects of stage of pregnant ewe supplementation and gestation weight gain in Ethiopian Menz sheep

Multiple gestation is associated with increased maternal, perinatal, and infant mortality. The prevalence of multiple gestation varies widely with the highest rates reported among populations in Africa. There have been few population-based studies of the impact of multiple gestation on pregnancy outcomes in sub-Saharan Africa. Data from a 1987-1990 prospective study of the effect of malaria chemoprophylaxis among pregnant women on birthweight and mortality of their infants in a rural area of Malawi were used to estimate the prevalence of multiple gestation and to quantify the risk of mortality associated with multiple gestation compared with single gestation. There were 88 (2.2%) multiple gestations among 4049 women. Mortality was high; only 38% of mothers were known to have all their infants survive to 1 year, compared with 74% in singleton gestations. The increased mortality associated with multiple gestation was due to two factors: a higher frequency of low birthweight and a fourfold increase in perinatal mortality among the infants with birthweights > or = 2500 g and among infants with unknown birthweight. We estimated that multiple gestation contributes to 5.5% of the perinatal, 1.2% of the postperinatal, and 11.5% of the maternal deaths in this population. Multiple gestation in Malawi contributed to increased perinatal and maternal mortality, but did not increase the risk of mortality after the perinatal period.

Trends in the prevalence of cerebral palsy in children born between 1988 and 2007 in Okinawa, Japan

BackgroundDespite twinning being common in Africa, few prospective twin studies have been conducted. We studied twinning rate, perinatal mortality and the clinical characteristics of newborn twins in urban Guinea-Bissau.MethodsThe study was conducted at the Bandim Health Project (BHP), a health and demographic surveillance site in Bissau, the capital of Guinea-Bissau. The cohort included all newborn twins delivered at the National Hospital Simão Mendes and in the BHP study area during the period September 2009 to August 2011 as well as singleton controls from the BHP study area. Data regarding obstetric history and pregnancy were collected at the hospital. Live children were examined clinically. For a subset of twin pairs zygosity was established by using genetic markers.ResultsOut of the 5262 births from mothers included in the BHP study area, 94 were twin births, i.e. a community twinning rate of 18/1000. The monozygotic rate was 3.4/1000. Perinatal mortality among twins vs. singletons was 218/1000 vs. 80/1000 (RR = 2.71, 95% CI: 1.93-3.80). Among the 13783 hospital births 388 were twin births (28/1000). The hospital perinatal twin mortality was 237/1000.Birth weight < 2000g (RR = 4.24, CI: 2.39-7.51) and caesarean section (RR = 1.78, CI: 1.06-2.99) were significant risk factors for perinatal twin mortality. Male sex (RR = 1.38, CI: 0.97-1.96), unawareness of twin pregnancy (RR = 1.64, CI: 0.97-2.78) and high blood pressure during pregnancy (RR = 1.77, CI: 0.88-3.57) were borderline non-significant. Sixty-five percent (245/375) of the mothers who delivered at the hospital were unaware of their twin pregnancy.ConclusionsTwins had a very high perinatal mortality, three-fold higher than singletons. A birth weight < 2000g was the strongest risk factor for perinatal death, and unrecognized twin pregnancy was common. Urgent interventions are needed to lower perinatal twin mortality in Guinea-Bissau.

BackgroundSeveral studies have shown that maternal HIV infection is associated with adverse pregnancy outcomes such as low birth weight and perinatal mortality. However, the association is conflicted with the effect of antiretroviral therapy (ART) on the pregnancy outcomes and it remains unexamined. If the association is confirmed then it would guide policy makers towards more effective prevention of mother to child HIV transmission interventions. Using methods for matching possible confounders, the objectives of the study were to assess the effect of maternal HIV infection on birth weight and perinatal mortality and to investigate the effect of ART on these two pregnancy outcomes in HIV-infected women.MethodsData on 4111 and 4759 children, born within five years of the 2010 and 2015-16 Malawi Demographic and Health Surveys (MDHS) respectively, whose mothers had an HIV test result, were analysed. A best balancing method was chosen from a set of covariate balance methods namely, the 1:1 nearest neighbour (NN) matching, matching on the propensity score (PS) and inverse weighting on the PS. HIV and ART data were only available in the MDHS 2010, permitting an assessment of the moderating effect of ART on the association between maternal HIV infection and birth weight and perinatal mortality.ResultsThe overall average birth weight was 3227.9g (95% CI: 3206.4, 3249.5) in 2010 and 3226.4g (95%: 3205.6, 3247.2) in 2015-16 and perinatal mortality was 3.8% (95%: 3.2, 4.3) in 2010 and 3.5% (95%: 2.8, 3.8) in 2015-16. The prevalence of HIV among the mothers was 11.1% (95%: 10.1, 12.0) and 9.2% (95% CI: 8.4, 10.1) in 2010 and 2015-16, respectively. In 2010, maternal HIV infection was negatively associated with birth weight (mean= -25.3g, 95% CI:(-95.5, -7.4)) and in 2015-16 it was positively associated with birth weight (mean= 116.3g, 95% CI:(27.8, 204.7)). Perinatal mortality was higher in infants of HIV-infected mothers compared to infants of HIV-uninfected mothers (OR = 1.5, 95% CI:(1.1 - 3.1)) in 2010, while there was no difference in the rate in 2015-16 (OR = 1.0, 95% CI:(0.4, 1.6)). ART was not associated with birth weight, however, it was associated with perinatal mortality (OR=3.9, 95% CI:(1.1, 14.8)).ConclusionThe study has found that maternal HIV infection had an adverse effect on birth weight and perinatal mortality in 2010. Birth weight was not dependent on ART uptake but perinatal mortality was higher among infants of HIV-infected mothers who were not on ART. The higher birth weight among HIV-infected mothers and similarity in perinatal mortality with HIV-uninfected mothers in 2015-16 may be indicative of successes of interventions within the PMTCT program in Malawi.

Birth Weight as a Predictor of Calving Ease and Perinatal Mortality in Holstein Cattle

Treating periodontal disease for preventing adverse birth outcomes in pregnant women.

Objective. —To compare perinatal mortality in the United States and Norway, using a new analytic approach based on relative birth weight. Design. —Comparison of linked birth and perinatal death records for US and Norwegian births from 1986 through 1987, the most recently available 2-year period. Setting. —Norway and the United States. Participants. —A total of 7445914 US births and 105084 Norwegian births. Interventions. —None. Main Outcome Measure. —Perinatal weight-specific mortality after adjustment for each country's own mean birth weight. Results. —The higher rate of perinatal death in the United States compared with Norway is due to an excess of preterm deliveries in the United States. Low-weight, preterm births comprise 2.9% of US births compared with 2.1% of Norwegian births. If the United States could eliminate this slight excess of preterm delivery, perinatal mortality in the United States would decrease to the level in Norway. Unexpectedly, the survival of newborns at any given birth weight is virtually the same in the United States and Norway when newborns' birth weights are considered relative to their own nation's mean weight. Conclusions. —Low rates of perinatal mortality in the Scandinavian countries have usually been attributed to the heavier weights of their newborns. Higher mortality among US infants is in fact due entirely to a small excess of preterm deliveries. The lighter weights of US newborns at term appear not to affect perinatal survival. Furthermore, the apparent survival advantage of low-weight US newborns (used by policymakers as evidence of superior US intensive neonatal care) may be at least partly an artifact. When weight-specific mortality rates are adjusted to relative birth weight, low-weight newborns have the same survival in Norway as in the United States. The prevention of excess mortality among US infants depends on the prevention of preterm births, not on changes in mean birth weight. (JAMA. 1995;273:709-711)

Objective. An improvement in perinatal mortality is reported in various countries. This is a retrospective analysis of perinatal and neonatal mortality in Northwest (NW) Greece.Methods. Analysis was made of the births and deaths register in NW Greece and records of the regional referral tertiary care center and the National Hospitals at the same area for the period 1996–2004. Perinatal mortality was analysed according to birthweight (BW) and gestational age (GA) for two separate periods, 1996–1999 (I) and 2000–2004 (II), corresponding to an increase in antenatal steroid use from 20% to 63%.Results. Neonatal mortality improved between the two periods in infants with very low BW [very low birth weight (VLBW), <1500 g] and the very preterm infants (<28 weeks GA). Severe respiratory distress syndrome (RDS) decreased (p < 0.001) for infants with GA ≤ 34 weeks and those with BW 751–1500 g (p < 0.02), and perinatal asphyxia is no longer a leading cause of death. Intrauterine transfer increased (p < 0.001) for infants with BW ≤ 1500 g. The main cause of death as derived from birth records and neonatal intensive care unit records is prematurity, alone or with complications.Conclusions. With the introduction of antenatal steroids and increase in intrauterine transfer there has been a decrease in neonatal mortality of VLBW infants in NW Greece.

Complicaciones neonatales del síndrome HELLP

The importance of low blood urea nitrogen levels in pregnant patients undergoing hemodialysis to optimize birth weight and gestational age

The rate of maternal and perinatal complications increases after 39 weeks' gestation in both unselected and complicated pregnancies. The aim of this study was to synthesize quantitatively the available evidence on the effect of elective induction of labor at 39 weeks on the risk of Cesarean section, and on maternal and perinatal outcomes. PubMed, US Registry of Clinical Trials, SCOPUS and CENTRAL databases were searched from inception to August 2018. Additionally, the references of retrieved articles were searched. Eligible studies were randomized controlled trials of singleton uncomplicated pregnancies in which participants were randomized between 39 + 0 and 39 + 6 gestational weeks to either induction of labor or expectant management. The risk of bias of individual studies was assessed using the Cochrane Risk of Bias Tool. The overall quality of evidence was assessed according to the GRADE guideline. Primary outcomes included Cesarean section, maternal death and admission to the neonatal intensive care unit (NICU). Secondary outcomes included operative delivery, Grade-3/4 perineal laceration, postpartum hemorrhage, maternal infection, hypertensive disease of pregnancy, maternal thrombotic events, length of maternal hospital stay, neonatal death, need for neonatal respiratory support, cerebral palsy, length of stay in NICU and length of neonatal hospital stay. Pooled risk ratios (RRs) were calculated using random-effects models. The meta-analysis included five studies (7261 cases). Induction of labor was associated with a decreased risk for Cesarean section (moderate quality of evidence; RR 0.86 (95% CI, 0.78-0.94); I2 = 0.1%), maternal hypertension (moderate quality of evidence; RR 0.65 (95% CI, 0.57-0.75); I2 = 0%) and neonatal respiratory support (moderate quality of evidence; RR 0.73 (95% CI, 0.58-0.95); I2 = 0%). Neonates born after induction weighed, on average, 81 g (95% CI, 63-100 g) less than those born after expectant management. No significant effects were found for the other outcomes with the available data. The main limitation of our analysis was that the majority of data were derived from a single large study. A second limitation arose from the open-label design of the studies, which may theoretically have affected the readiness of the attending clinician to resort to Cesarean section. Elective induction of labor in uncomplicated singleton pregnancy at 39 weeks' gestation is not associated with maternal or perinatal complications and may reduce the need for Cesarean section, risk of hypertensive disease of pregnancy and need for neonatal respiratory support. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.