(848) Association of interpregnancy interval and perinatal outcomes among individuals with history of PPROM

To examine the association of interpregnancy interval with adverse perinatal outcomes among individuals with a history of preterm prelabor rupture of membranes (PPROM).

Study Design:

This was a retrospective cohort study of two consecutive births in California between 2008-2020 among patients with a history of PPROM in the index pregnancy. Interpregnancy interval (IPI) was categorized as < 12 months, 12-23 months, 24-35 months, 36-59 months, and ≥60 months. Outcomes included gestational hypertension, preeclampsia, preterm birth ( < 37 weeks), severe maternal morbidity (SMM), and primary cesarean delivery. Chi squared and multivariable logistic regression were used for statistical analysis.

Results:

In our cohort of 15,271 individuals with a history of PPROM in an index pregnancy, 3,299 (21.6%) had a short IPI ( < 12 months) and 1,537 had a long IPI (≥60 months). As compared to IPI of 12-23 months, pregnancies with IPI < 12 months had greater odds of preterm birth (24.10% vs 19.54%; aOR 1.22, 95% CI 1.09-1.37), SMM (1.52% vs 0.86%; aOR 1.58, 95% CI 1.03-2.43), and primary cesarean delivery (11.3% vs 9.26%; aOR 1.28, 95% CI 1.08-1.53). Pregnancies with IPI≥60 months also had increased odds of adverse outcomes including preeclampsia (6.57% vs 3.63%; aOR 1.66, 95% CI 1.28-2.15), preterm birth (24.20% vs 19.54%; aOR 1.22, 95% CI 1.06-1.41), SMM (1.95% vs 0.86%; aOR 1.85, 95% CI 1.12-3.03), and primary cesarean (13.63% vs 9.26%; aOR 1.45, 95% CI 1.17-1.80).

Conclusion:

Both short ( < 12 months) and long (≥60 months) IPIs were associated with adverse perinatal outcomes among patients with a history of PPROM. These findings highlight the importance of counseling those with PPROM in a prior pregnancy on optimal pregnancy timing to mitigate risks in subsequent pregnancies.