Prenatal Care Content, Utilization, Risk Resolution, and Birth Outcomes among Overweight and Obese Women

Obesity is an epidemic in the United States. However, past research has rarely examined the role of prenatal care in preventing excessive fetal growth, a precursor for childhood obesity. In addition, most prenatal care research has not accounted for resolution of risks within pregnancy. Using South Carolina’s birth certificate-linked Medicaid Claims data, this dissertation research examined the rate of early diabetes screening (<20 weeks gestation, defined using claims codes from the Medicaid file), the predictors of early diabetes screening among eligible women, and the relationships between early diabetes screening, prenatal care utilization (Adequacy of Prenatal Care Utilization Index), and excessive fetal growth among overweight and obese women who enter prenatal care early, by ultimate gestational diabetes (GDM) status of the woman. Excessive fetal growth was defined as high birthweight [HBW], ≥4000g or ≥4500g, and large for gestational age [LGA], >90th or >95th percentile for gestational age. The study also examined if risk resolution (gestational weight gain or control of GDM in late pregnancy) mediated these relationships. Overall, only 29% of South Carolinian obese women on Medicaid received early diabetes screening. Adjusting for covariates, older women, non-Hispanic black women, women of higher education, women in small rural and isolated areas, women who received the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), and women with greater body mass index were more likely to receive early diabetes screening. After adjusting for covariates, receipt of early diabetes screening was associated with lower odds of HBW/LGA among primiparous GDM overweight/obese women, but this was not shown among multiparous GDM overweight/obese women or among non-GDM overweight/obese women. Adequate/intermediate prenatal care utilization was associated with reduced risk of LGA outcomes among GDM overweight/obese women, but this relationship was not mediated through gestational weight gain or control of GDM in late pregnancy. Instead, non-excessive gestational weigh gain, control of GDM in late pregnancy, and adequate/intermediate prenatal care utilization were associated with reduced risk of LGA after controlling for each other and covariates. This study revealed that early diabetes screening, adequacy of prenatal care utilization, non-excessive gestational weight gain, and control of GDM in late pregnancy were distinct pathways that result in reduced risk of LGA in distinct populations. Measures developed in this study, including early diabetes screening and risk resolution variables can be used to monitor and improve the quality of prenatal care.