Analysis of Factors Contributing to Antenatal Corticosteroid Administration in Patients Presenting with Threatened Preterm Labor

Abstract

Objective This study aimed to analyze characteristics of those seen for threatened preterm labor (tPTL) who receive antenatal corticosteroids (ACS) to better understand clinical decision-making. Study Design This retrospective cohort study consisted of patients seen in triage at an urban county hospital in 2021 for tPTL during pregnancy. Demographic variables (maternal age, race/ethnicity, and prior preterm delivery) and obstetrical variables (cervical dilation, effacement, membrane rupture, and tocolytic administration) were evaluated against the primary outcome of ACS administration. Results After exclusions, a cohort of 290 pregnant people with 372 unique encounters for tPTL remained. The mean maternal age was 26.7, and 15.6% of patients had a history of prior preterm birth. A total of 107 patients in 111 encounters received ACS, which were associated with lower body mass index (BMI), greater cervical dilation, greater effacement, membrane rupture, and more frequent contractions (all ps < 0.01). The mean presentation was at 33.5 weeks. Only 44% of those receiving ACS delivered within 7 days, compared with 11% of those who did not receive ACS (p < 0.001). Half (50%) of the patients receiving ACS delivered at >37 weeks. Adjusting for significant factors in the univariable analysis and limited to first encounter in triage, BMI (odds ratio: 0.91, 95% confidence interval: 0.87–0.95), cervical dilation ≥ 2 cm (2.49, 1.12–5.35), and cervical effacement ≥ 50% (4.80, 2.25–10.24) were significantly associated with patients receiving ACS. Conclusion Greater cervical dilation and effacement and a lower BMI were associated with ACS administration, although most patients receiving ACS still did not deliver within 7 days. Key Points