198: Inadequate prenatal care increases the risk for stillbirth

Abstract

To determine whether inadequate prenatal care (PNC) utilization is associated with stillbirth (SB). The Stillbirth Collaborative Research Network (SCRN) was a population-based case control study that enrolled all SB (cases) and a representative sample of live births (LB; controls) in 5 geographic areas. The Adequacy of Prenatal Care Utilization Index (APCNU) was used to divide PNC into 4 classes based on gestational age (GA) at initiation to PNC and percentage of recommended visits (RV) received. Number of RV depends on both GA of the newborn and GA at entry to PNC, based on American College of Obstetrics and Gynecology guidelines. Quality of PNC was defined as: Inadequate (care begun after month 4 or <50% of RV), Intermediate (care begun by month 4 and 50-79% of RV), Adequate (care begun by month 4 and 80-109% of RV), and AdequatePlus (care begun by month 4 and ≥110% of RV). Analysis used Univariate chi-squared tests, student t-tests, and multivariable logistic regression. Of 2393 participants with data in SCRN, 594 SB and 1799 LB were identified. Of these, 21.8% (522) had Inadequate PNC, 6.1%(146) had Intermediate PNC, 27% (646) had Adequate PNC, and 45% (1079) had AdequatePlus PNC. The median number of PNC visits was 6 (4/9 for 25-75%) for SB and 10 (7/12, 25-75%) for LB (p<0.001). The mean (± SD) GA at initiation to PNC was 11.3±5.76 weeks for SB and 12±6.57 weeks for LB (p=0.01). Inadequate PNC was associated with SB in univariate analysis (p<0.001). Placental abruption, pre-delivery antibiotics, induction of labor, fetal sex, history of pregnancy loss or SB, pre-gestational diabetes mellitus, chronic hypertension, maternal BMI, cigarette use within 3 months of pregnancy, marital status, and fetal anomaly were also associated with SB in univariate analysis (p<0.05). Inadequate PNC remained associated with SB in multivariable analysis after adjusting for risk factors (OR=1.66, 95%CI: 1.05-2.66. p<0.001, see Table 1 for covariates, R2=0.19). In this model, Intermediate PNC (OR=2.59, 95%CI: 1.04-2.66) or AdequatePlus PNC (OR=4.01, 95%CI: 2.72-5.92) also increased the risk of SB compared to women with Adequate PNC. Inadequate and Intermediate PNC is associated with an increased risk for SB. Although having AdequatePlus PNC was associated with an increased risk for SB, this may be due to high-risk conditions requiring more visits. PNC quality may be a modifiable risk factor for SB.