Racial/Ethnic Inequities in Low Birth Weight and Preterm Birth: The Role of Multiple Forms of Stress.

Introduction Racial/ethnic inequities in low birth weight (LBW) and preterm birth (PTB) persist in the United States. Research has identified numerous risk factors for adverse birth outcomes; however, they do not fully explain the occurrence of, or inequalities in PTB/LBW. Stress has been proposed as one explanation for differences in LBW and PTB by race/ethnicity. Methods Using the Pregnancy Risk Assessment Monitoring System (PRAMS) data from 2012 to 2013 for 21 states and one city (n = 15,915) we used Poisson regression to estimate the association between acute, financial and relationship stressors and LBW and PTB, and to examine the contribution of these stressors individually and simultaneously to racial/ethnic differences in LBW and PTB. Results Adjusting for age and race/ethnicity, acute (p < 0.001), financial (p < 0.001) and relationship (p < 0.05) stressors were associated with increased risk of LBW, but only acute (p < 0.05) and financial (p < 0.01) stress increased risk of PTB. Across all models, non-Hispanic blacks had higher risk of LBW and PTB relative to non-Hispanic whites (IRR 1.87, 95% CI 1.55, 2.27 and IRR 1.46, 95% CI 1.18, 1.79). Accounting for the effects of stressors attenuated the risk of LBW and PTB by 17 and 22% respectively, but did not fully explain the increased likelihood of LBW and PTB among non-Hispanic blacks. Discussion Results of this study demonstrate that stress may increase the risk of LBW and PTB. While stressors may contribute to racial/ethnic differences in LBW and PTB, they do not fully explain them. Mitigating stress during pregnancy may help promote healthier birth outcomes and reduce racial/ethnic inequities in LBW and PTB.

Racial/Ethnic and nativity differences in birth outcomes among mothers in New York City: the role of social ties and social support.

Immigrants have lower rates of low birth weight (LBW) and to some extent preterm birth (PTB), than their US-born counterparts. This pattern has been termed the 'immigrant health paradox'. Social ties and support are one proposed explanation for this phenomenon. We examined the contribution of social ties and social support to LBW and PTB by race/ethnicity and nativity among women in New York City (NYC). The NYC Pregnancy Risk Assessment Monitoring System survey (2004-2007) data, linked with the selected items from birth certificates, were used to examine LBW and PTB by race/ethnicity and nativity status and the role of social ties and social support to adverse birth outcomes using bivariate and multivariable analyses. SUDAAN software was used to adjust for complex survey design and sampling weights. US- and foreign-born Blacks had significantly increased odds of PTB [adjusted odds ratio (AOR) = 2.43, 95 % CI 1.56, 3.77 and AOR = 2.6, 95 % CI 1.66, 4.24, respectively] compared to US-born Whites. Odds of PTB among foreign-born Other Latinas, Island-born Puerto Ricans' and foreign-born Asians' were not significantly different from US-born Whites, while odds of PTB for foreign-born Whites were significantly lower (AOR = 0.47, 95 % CI 0.26, 0.84). US and foreign-born Blacks' odds of LBW were 2.5 fold that of US-born Whites. Fewer social ties were associated with 32-39 % lower odds of PTB. Lower social support was associated with decreased odds of LBW (AOR 0.69, 95 % CI 0.50, 0.96). We found stronger evidence of the immigrant health paradox across racial/ethnic groups for PTB than for LBW. Results also point to the importance of accurately assessing social ties and social support during pregnancy and to considering the potential downside of social ties.

Maternal and hospital characteristics of non-medically indicated deliveries prior to 39 weeks.

Non-medically indicated (NMI) deliveries prior to 39 weeks increase the risk of neonatal mortality, excess morbidity, and health care costs. The study's purpose was to identify maternal and hospital characteristics associated with NMI deliveries prior to 39 weeks. The study included 207,775 births to women without a previous cesarean and 38,316 births to women with a previous cesarean, using data from Florida's 2006-2007 linked birth certificate and inpatient record file. Adjusted risk ratios (ARR) and 95 % confidence intervals (CI) for characteristics were calculated using generalized estimating equation for multinomial logistic regression. Among women without a previous cesarean, NMI deliveries occurred in 18,368 births (8.8 %). Non-medically indicated inductions were more likely in women who were non-Hispanic white (ARR: 1.41, 95 % CI 1.31-1.52), privately-insured (ARR: 1.42, 95 % CI 1.26-1.59), and delivered in hospitals with <500 births per year. Non-medically indicated primary cesareans were more likely in women who were older than 35 years (ARR: 2.96, 95 % CI 2.51-3.50), non-Hispanic white (ARR: 1.44, 95 % CI 1.30-1.59), and privately-insured (ARR: 1.43, 95 % CI 1.17-1.73). Non-medically indicated primary cesareans were also more likely to occur in hospitals with <30 % nurse-midwife births, <500 births per year, and in large metro areas. Among women with previous cesarean, NMI repeat cesareans occurred in 16,746 births (43.7 %). Only weak risk factors were identified for NMI repeat cesareans. The risk factors identified varied by NMI outcome. This information can be used to inform educational campaigns and identify hospitals that may benefit from quality improvement efforts.

The relationship between cesarean delivery and gestational age among US singleton births.

The increasing trend of delivering at earlier gestational ages has raised concerns of the impact on maternal and infant health. The delicate balance of the risks and benefits associated with continuing a pregnancy versus delivering early remains challenging. Among singleton live births in the United States, the proportion of preterm births increased from 9.7% to 10.7% between 1996 and 2004. The increase in singleton preterm births occurred primarily among those delivered by cesarean section, with the largest percentage increase in late preterm births. For all maternal racial/ethnic groups, singleton cesarean section rates increased for each gestational age group. Singleton cesarean section rates for non-Hispanic black women increased at a faster pace among all preterm gestational age groups compared with non-Hispanic white and Hispanic women. Further research is needed to understand the underlying reasons for the increase in cesarean section deliveries resulting in preterm birth.

Changes in the gestational age distribution among U.S. singleton births: impact on rates of late preterm birth, 1992 to 2002.

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.

A multistate quality improvement program to decrease elective deliveries before 39 weeks of gestation.

OBJECTIVE: Nonmedically indicated (elective) deliveries before 39 weeks of gestation result in unnecessary neonatal morbidity. We sought to determine whether implementation of a process improvement program will decrease the rate of elective scheduled singleton early-term deliveries (37 0/7-38 6/7 weeks of gestation) in a group of diverse community and academic hospitals. METHODS: Policies and procedures for scheduling inductions and cesarean deliveries were implemented and patient and health care provider education was provided. Outcomes for scheduled singleton deliveries at 34 weeks of gestation or higher were submitted through a web-based data entry system. The rate of scheduled singleton elective early-term deliveries as well as the rates of early-term medically indicated and unscheduled deliveries, neonatal intensive care unit admissions, and singleton term fetal mortality rate were evaluated. RESULTS: A total of 29,030 scheduled singletons at 34 weeks of gestation or higher were delivered in 26 participating hospitals between January 2011 and December 2011. Elective scheduled early-term deliveries decreased from 27.8% in the first month to 4.8% in the 12th month (P<.001); rates of elective scheduled singleton early-term inductions (72%, P=.029) and cesarean deliveries (84%; P<.001) decreased significantly. There was no change in medically indicated or unscheduled early-term deliveries. Neonatal intensive care unit admissions among scheduled early-term singletons decreased nonsignificantly from 1.5% to 1.2% (P=.24). There was no increase in the term fetal mortality rate. CONCLUSION: A rapid-cycle process improvement program substantially decreased elective scheduled early-term deliveries to less than 5% in a group of diverse hospitals across multiple states. LEVEL OF EVIDENCE: III.

Term pregnancy: a period of heterogeneous risk for infant mortality.

OBJECTIVE: To estimate the trend of maternal racial and ethnic differences in mortality for early-term (37 0/7 to 38 6/7 weeks of gestation) compared with full-term births (39 0/7 to 41 6/7 weeks of gestation). METHODS: We analyzed 46,329,018 singleton live births using the National Center for Health Statistics U.S. period-linked birth and infant death data from 1995 to 2006. Infant mortality rates, neonatal mortality rates, and postneonatal mortality rates were calculated according to gestational age, race and ethnicity, and cause of death. RESULTS: Overall, infant mortality rates have decreased for early-term and full-term births between 1995 and 2006. At 37 weeks of gestation, Hispanics had the greatest decline in infant mortality rates (35.4%; 4.8 per 1,000 to 3.1 per 1,000) followed by 22.4% for whites (4.9 per 1,000 to 3.8 per 1,000); blacks had the smallest decline (6.8%; 5.9 per 1,000 to 5.5 per 1,000) as a result of a stagnant neonatal mortality rate. At 37 weeks compared with 40 weeks of gestation, neonatal mortality rates increase. For Hispanics, the relative risk is 2.6 (95% confidence interval [CI] 2.0-3.3); for whites, the relative risk is 2.6 (95% CI 2.2-3.1); and for blacks, the relative risk is 2.9 (95% CI 2.2-3.8). Neonatal mortality rates are still increased at 38 weeks of gestation. At both early- and full-term gestations, neonatal mortality rates for blacks are 40% higher than for whites and postneonatal mortality rates 80% higher, whereas Hispanics have a reduced postneonatal mortality rate when compared with whites. CONCLUSION: Early-term births are associated with higher neonatal, postneonatal, and infant mortality rates compared with full-term births with concerning racial and ethnic disparity in rates and trends.

Trends and racial/ethnic disparities in gestational diabetes among pregnant women in New York City, 1990-2001.

We analyzed gestational diabetes mellitus trends in New York City between 1990 and 2001 by using information obtained from birth certificates. Gestational diabetes diagnoses among women who delivered babies increased 46%, from 2.6% (95% confidence interval [CI]=2.5, 2.7) to 3.8% (95% CI=3.7, 3.9) of births. Prevalence was highest among South and Central Asian women (11%). Given risks for adverse fetal outcomes and maternal chronic diabetes, prompt screening is critical. Metabolic control should be maintained during pregnancy and assessed postpartum for women with gestational diabetes.