Disparities In Pregnancy Outcomes Research Articles

Contribution of late fetal deaths to US perinatal mortality rates, 1995–1998

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.

Prematurity at birth: trends, racial disparities, and epidemiology.

While infant mortality rates have continued to decline in the U.S., low birth weight and preterm rates have dramatically increased. Although the combination of factors that underlies these trends has not been fully described, there is growing concern that an appreciable part of the rise in prematurity rates stems from efforts taken to improve the survival of these high-risk infants. While advancements in medical technology and practice, augmented by improvements in prenatal care use, may have adversely effected prematurity rates and played a role in broadening racial disparities in pregnancy outcomes, they have positively impacted infant survival. Although many risk factors for prematurity have been identified, there are presently few areas for effective prevention. Accordingly, there is little encouragement for a downturn in prematurity rates in the near future. The prospect of continuing growth in the annual number of surviving preterm infants in the U.S. highlights the need for early detection and treatment of developmental problems for these high-risk survivors, and emphasizes the importance of assuring that needed support services are available to these children and their families.

Socio-economic disparities in pregnancy outcome: why do the poor fare so poorly?

In this paper, we review the evidence bearing on socio-economic disparities in pregnancy outcome, focusing on aetiological factors mediating the disparities in intrauterine growth restriction (IUGR) and preterm birth. We first summarise what is known about the attributable determinants of IUGR and preterm birth, emphasising their quantitative contributions (aetiological fractions) from a public health perspective. We then review studies relating these determinants to socio-economic status and, combined with the evidence about their aetiological fractions, reach some tentative conclusions about their roles as mediators of the socio-economic disparities. Cigarette smoking during pregnancy appears to be the most important mediating factor for IUGR, with low gestational weight gain and short stature also playing substantial roles. For preterm birth, socio-economic gradients in bacterial vaginosis and cigarette smoking appear to explain some of the socio-economic disparities; psychosocial factors may prove even more important, but their aetiological links with preterm birth require further clarification. Research that identifies and quantifies the causal pathways and mechanisms whereby social disadvantage leads to higher risks of IUGR and preterm birth may eventually help to reduce current disparities and improve pregnancy outcome across the entire socio-economic spectrum.

Gaps in Nutrition and Health Status Between Black and White Low-Income Infants, Children and Women

Racial disparity in pregnancy outcomes has been reported in many studies. It is important in program development to determine how wide the gaps are between racial groups in nutrition and health status among low-income infants, children, and women. Method: The Pediatric and Pregnancy Nutrition Surveillance Systems (PedNSS, PNSS) were developed by the Centers for Disease Control and Prevention to monitor nutritional risk factors among children aged 0-4 years old and women who enrolled in public health programs such as WIC. In Missouri, the WIC program contributes almost 100% of records in PedNSS and PNSS. The Missouri PedNSS and PNSS records from 1993 through 1997 were reviewed to compare the prevalence rates of nutritional health indicators such as anemia, underweight, and low birth weight between Black and White WIC program participants. Findings: 1) The gap in prevalence rate of anemia between Black and White children increased from 11.5% in 1993 to 14.2% in 1997; 2) The prevalence of anemia among Black mothers during the first and second trimesters has consistently been twice as high as those of White mothers, and three times during third trimester and postpartum; and 3) Low birth weight rate among Black babies is about 1.7 times as high as that of White babies. Conclusions/Recommendations: In Missouri, there are large gaps in children's growth status, low birth weight rate, and anemia prevalence rate between Black and White WIC program participants. In order to promote success of nutrition and behavior interventions aimed at low-income Blacks, culturally sensitive messages need to be developed and delivered to this population.

Racial Differences in Pregnancy Outcomes

Black mothers in the United States are twice as likely as their white counterparts to experience a wide variety of adverse pregnancy outcomes, including prematurity, low birth weight, and infant and fetal death. Although blacks have higher proportions of births with maternal risk factors such as young age, high birth order, low education, and unmarried mothers, these differences do not account for their higher rates of adverse outcomes; the reasons for the excess remain largely unknown. To develop effective interventions to reduce the racial disparities in pregnancy outcome, we must further our understanding of the mechanisms underlying premature onset of labor and intrauterine growth.

Racial Disparities in Pregnancy Outcomes: The Role of Prenatal Care Utilization and Maternal Risk Status

Distinct black-white differences in pregnancy outcome and prenatal care utilization have been a persistent feature of U.S. natality-related statistics. Using South Carolina and North Carolina live birth-infant death cohort files for 1978-1982, this study examines the extent to which variations in prenatal care utilization may be associated with racial disparities in pregnancy outcome within maternal sociomedical risk groups. After taking indicators of maternal risk into account (age-parity, education, marital status, complications of pregnancy and previous pregnancy terminations), birth weight and gestational age distributions and birth weight- and gestational age-specific neonatal mortality rates of blacks and whites were compared by level of prenatal care utilization. Distinct racial differences in birth weight and gestational age distributions were observed within equivalent maternal risk and prenatal care categories, with whites having an approximately 200-gram mean birth weight and five-day mean gestational age advantage compared to blacks. In this analysis of more than 650,000 cases, low-risk blacks adequately utilizing prenatal care had a lower mean birth weight (3,266 grams) and a higher neonatal mortality rate (6.6) than low-risk, inadequate-care whites (3,302 grams; 6.1).