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

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 s < 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 ( < 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: · In a cohort of 290 patients with 373 encounters for threatened preterm labor, 37% received ACS.. · We found that only 40% of those who received ACS delivered within 7 days and half went on to deliver at term.. · Cervical dilation ≥2 cm (odds ratio, 95% confidence interval: 2.49, 1.12-5.35) and effacement ≥50% (4.80, 2.25-10.24) were independently associated with receiving ACS..