(1021) Preterm delivery risk in women with a prior pregnancy complicated by previable PPROM (pPPROM)

Preterm delivery (PTD), defined by ACOG as delivery from 20w0d to 36w6d, can be a devastating finding often associated with severe fetal morbidity and mortality. In addition, these pregnancies have a heightened risk for preterm delivery in a subsequent pregnancy. A method to reduce this elevated risk is to offer cervical length screening and possible cerclage in a subsequent pregnancy.  However, in women who rupture prior to 20w, data and guidance are sorely lacking. 


Study Design:

This was a multi-center, retrospective cohort study of women with previable PPROM divided into < 20w (16w0d -19w6d) and ≥20w (20w0d -22w6d) collected from 1/1/2010-12/31/2020. Exclusion criteria included fetal demise prior to PPROM, multiples, and PPROM at < 16w or ≥23w. Primary outcome was gestational age (GA) at delivery ( >37w vs ≤37w) in a subsequent pregnancy. Secondary outcomes included the rate of chorioamnionitis, placental abruption in the index pregnancy, rate of PPROM and PTB in the immediately ensuing pregnancy, progesterone use (intramuscular or vaginal), and neonatal outcomes. 


Results:

133 patients with pPPROM met criteria, 67 patients < 20w vs 66 patients  ≥20w. 63 of these women had a recorded subsequent pregnancy. The rate of PTD was similar between < 20w and ≥20w group, 33% vs 41.7% (p = 0.50) respectively. Within these two gestational cohorts, both groups suffered comparable rates of PPROM, 19.4% (< 20w) vs 18.2% (≥20w) (p = 0.99), at subsequent pregnancy. Diagnosis of chorioamnionitis and placental abruption in the index pregnancy was similar between the two cohorts (p = 0.61 and 0.11, respectively). Progesterone use (IM vs vaginal vs none) was similar between cohorts in both the index and subsequent pregnancy (p = 0.10 and 0.98, respectively). Neonatal demise at index pregnancy was markedly different with 91.0% suffering mortality < 20w compared to 69.7% ≥20w (p = 0.002).  


Conclusion:

The rate of recurrent preterm birth in < 20w parallels those who deliver ≥20w. This finding would suggest that women who suffer pPPROM prior to 20 weeks should also be offered similar treatment.