777: Resolution of antenatal corticosteriod induced leukocytosis

Preterm premature rupture of membranes (PPROM) complicates 3% of all pregnancies. Infection may be either a cause or consequence of PPROM. Description of transient physiologic leukocytosis (WBC) following antenatal corticosteroid administration is not well described. Our objective was to identify average time for resolution of leukocytosis following antenatal corticosteroids. In a retrospective case-control study, singleton pregnancies admitted for antenatal corticosteroids after diagnosis of PPROM (n=24) or other indications (n=23) were enrolled for study. Maternal socio-demographic and clinical data were collected to include: maternal age, ethnicity, parity, indication for admission and delivery, baseline WBC, serial WBC counts obtained in the following 7 days, and placental pathology. Statistical analysis included Student′s T test and Fisher′s exact with p < 0.05 considered significant. Maternal age 33.1 vs. 35.1 yrs (p=0.36), Black ethnicity 60% vs. 26% (p=0.53), and nulliparity 50% vs. 43% (p=0.77) were not significantly different between PPROM and non-PPROM groups, respectively. Average time for resolution of the leukocytosis following antenatal corticosteroids did not differ between the PPROM and non-PPROM groups, 80.8 vs. 66.5 h (p=0.26). The time to WBC peak did differ between the PPROM and non-PPROM groups, 47 vs. 24.7 h (p=0.002). PPROM is a difficult clinical scenario to manage while balancing fetal maturation and timing of delivery. Our findings suggest a peak of leukocytosis within 1 to 2 days of antenatal corticosteroids with normalization of the WBC in 3 to 4 days. Elevation of the WBC after normalization should raise concern for infection.