181: Risk factors for stillbirth in a prospective, nulliparous cohort

Abstract

Data regarding stillbirth are derived from administrative databases and case-control studies. Our objective was to identify risk factors for stillbirth in a large, prospective study of nulliparous women with prenatal care initiated in the first trimester. Secondary analysis of the Nulliparous Pregnancy Outcomes Study (nuMoM2b), a prospective, multi-center observational cohort with data collection at three time points during pregnancy, visit 1 (V1) at 6w0d-13w6d, visit 2 (V2) at 16w0d-21w6d, and visit 3 (V3) at 22w0d-29w6d, and at delivery. Pre-pregnancy and early pregnancy characteristics of stillbirths and live births were compared using chi-square for categorical or t-test for continuous measures. Stillbirth was defined as fetal death > 20 weeks gestation with exclusion of pregnancy terminations. Standardized questionnaires measured maternal perceived stress (V1 and V3), depression (V1 and V3) and anxiety (V1). Fetal biometry and uterine artery Doppler measurements were performed at V2 and V3. Stillbirth occurred in 51 (0.53%) of 9551 deliveries included in this analysis. Sociodemographic factors associated with stillbirth included non-Hispanic black race (p=0.016), less than college education (p< 0.001), unmarried status (p< 0.001), government insurance (p=0.027), 100-200% of poverty level (p=0.004) and household income < $40,000/year (p=0.041) (Table). Pre-pregnancy medical characteristics associated with stillbirth included pregestational diabetes (p< 0.001) and seizure disorder (p=0.002). Perceived stress, depression and anxiety scores were similar among women with stillbirths and live births. Similarly, women who had stillbirths had similar fetal biometry and uterine artery Doppler at V2 and V3 as those who had live births. Risk factors for stillbirth in nulliparous women were largely similar to those found in case-control studies. It is noteworthy that non-Hispanic black race, low education and low socioeconomic status were associated with stillbirth despite receiving prenatal care.