Antepartum hospital use and delivery outcomes in California

There are few population-based studies of antepartum emergency department visits and inpatient hospitalizations and their implications for delivery outcomes.

The study aimed to analyze the likelihood of pregnant patients's antepartum hospital use using population-based hospital discharge data for births in California. The study analyzed associations between antepartum hospital use and the likelihood of maternal delivery complications and postpartum hospital use.

This was a population-based retrospective cohort study of individuals with live births in state-licensed hospitals in California in 2017. Delivery admissions data were linked to antepartum hospital visits within 280 days of a delivery admission and 90 days after a delivery discharge. The most common principal or primary International Classification of Diseases, Tenth Revision-coded diagnoses for antepartum emergency department visits and inpatient hospitalizations were identified and Poisson regression estimates were used to determine the likelihood of antepartum hospital use by maternal demographic and clinical characteristics. Complicated deliveries were defined by International Classification of Diseases, Tenth Revision-coded severe maternal morbidity, vaginal or cesarean delivery complications, or long length of stay after delivery (>4 days for a vaginal delivery and >5 days for a cesarean delivery). Associations between specific types of antepartum visits, complicated deliveries, and postpartum hospital use were analyzed by chi-square tests. Logistic regression estimates were used to determine the significance of associations between antepartum hospital use and likelihood of a complicated delivery.

Of 348,848 deliveries at 246 hospitals in California, in 2017, with linkable data, almost one-third of the patients (30.4% with emergency department visits and 1.2% with inpatient hospital stays) experienced antepartum hospital use. Those who were younger, identified as a racial or ethnic minority, and with a low income, were the most likely to have antepartum hospital use. The most common primary diagnoses for antepartum emergency department visits were threatened abortions (19.6%), urinary tract infections (11.2%), and hemorrhage (9.3%). The most common principal diagnoses for antepartum hospitalizations were preterm labor (14.3%), pyelonephritis (10.2%), and hyperemesis gravidarum (6.3%). Patients with any antepartum hospital use were significantly more likely to experience a delivery complication, even after controlling for conditions coded during the delivery admission. Although having an antepartum emergency department visit was associated with only modestly increased adjusted odds (odds ratio, 1.04; 95% confidence interval, 1.01-1.08) of a complicated delivery, patients with any antepartum hospitalizations, especially those with preterm prelabor rupture of membranes, hypertension, diabetes, or hemorrhage, were at higher risk (odds ratio, 1.38; 95% confidence interval, 1.28-1.47).

Antepartum hospital use is frequent and is associated with patient clinical and demographic factors. Addressing the high prevalence of antepartum hospital use should be a part of future quality improvement and health equity efforts focused on improving care for patients with the greatest medical and social needs.