Number of Prenatal Visits and Risk for Maternal Morbidity, 2016-2019

Abstract

There is little national data on whether number of prenatal visits is associated with maternal outcomes during delivery. This study analyzed the association between number of prenatal visits and maternal morbidity in the US. This cross-sectional study of live birth data from the National Vital Statistics System analyzed number of prenatal visits and risk for a maternal morbidity composite that included transfusion, 3rd/4th degree lacerations, uterine rupture, unplanned hysterectomy, and ICU admission. Births for all US residents who attended ≤20 prenatal visits from 2016-2019 were included. Quadratic regression was used to evaluate the association between number of prenatal visits and maternal morbidity. Separate analyses were performed for high vs. low risk patients. Patients with pre-gestational hypertension (HTN) or pre-gestational diabetes (DM) were classified as high risk; those without these diagnoses were classified as low risk. Sensitivity analyses of deliveries ≥37 weeks gestation was performed. Data from 14.9 million birth certificates were included. The mean number of prenatal visits was 11.3 for all patients, 13.1 for those with DM, and 12.3 for those with HTN. Number of prenatal visits varied significantly by maternal race, ethnicity, and payer (Table). Among low-risk patients, risk for morbidity was 1.3% and ranged from 1.2% to 1.5% based on number of prenatal visits. For high-risk patients, risk for morbidity decreased in the setting of ≥10 visits; risk increased significantly with fewer visits (Figure). Number of prenatal visits accounted for more variance in risk among high-risk (R2=0.93) than low risk patients (R2=0.45). In sensitivity analyses of deliveries ≥37 weeks gestation, the association between increased morbidity risk and fewer visits was similar. Number of prenatal visits varies by race, ethnicity, and payer. Fewer prenatal visits was associated with large differentials in risk among high risk patients. Optimizing prenatal care may be an important determinant of risk among high risk patients.View Large Image Figure ViewerDownload Hi-res image Download (PPT)