470: Betamethasone for threatened preterm labor: a clinical review at a single academic medical center

Abstract

To review timing of administration of betamethasone for pregnancies with threatened preterm labor or advanced cervical dilation A retrospective cohort study of patients who received betamethasone (BMZ) for the reduction of preterm morbidity was performed between July 1, 2004 and June 30, 2009. Rescue or repeat courses of BMZ were not administered. The Northwestern University Electronic Database Warehouse was used to identify all patients who received BMZ. Each identified patient was assigned a diagnosis of preterm labor (PL) if they received tocolysis or delivered imminently. Advanced cervical dilation (ACD) was defined as those patients who did not require tocolysis or deliver imminently. PL and ACD groups were stratified by the cervical dilation and cervical effacement at the time BMZ was administered. The primary outcome was the interval between the gestational age (GA) at BMZ administration and the GA at delivery. NICU length of stay and the percentage of patients who delivered within 7 days of BMZ administration were secondary outcomes. All data was analyzed with the Kruskal-Wallis test. Three hundred and fifty six patients received BMZ for PL and 247 patients for ACD. The median interval between administration of BMZ and delivery was 35 days for preterm labor and 47 days for advanced 28 days (p<0.0001). Compared to ACD patients, PL patients were more dilated (2 vs. 1 cm, p<0.0001) and more effaced (1.5 vs. 2 cm, p<0.0001) at the time of BMZ administration. There was no significant difference in the median NICU length of stay between PL and ACD patients. Only patients who presented with PL and were 3.5+ cm dilated or completely effaced delivered within 7 days of BMZ administration (p<0.005). For ACD patients, only those who were 0.5 cm effaced or less delivered within 7 days of BMZ administration (p<0.005). The interval between BMZ administration and delivery at our institution is greater than 7 days for patients who present with PL or ACD. Improvements need to be made in order to better triage patients who present with threatened PL or ACD. Tabled 1