Does low dose aspirin prescribed for risk of early onset preeclampsia reduce the prevalence of preterm prelabor rupture of membranes?

Background: Placental dysfunction, inflammation and degradation of fetal membranes has been hypothesized as a cause of preterm prelabor of rupture of membranes.Objective: To examine the effect of aspirin, an anti-inflammatory agent, on the prevalence of preterm prelabor rupture of membranes (PPRoMs).Methods: A retrospective analysis was conducted to examine the effect of aspirin on the prevalence of PPRoM. Aspirin (150 mg, nocte) was prescribed to women who were identified through a screening program at 11-13+6 weeks' gestation as being at high risk for developing early-onset preeclampsia. Women who were at low risk for developing preeclampsia did not receive aspirin. The prevalence of PPRoM was compared with an observational cohort.Results: In the observational cohort, there were 3027 women, including 32 (1.1%) cases of PPRoM. The prevalence of PPRoM in the high risk group was 3.1% (4/128) and was statistically significantly higher compared to the low risk group (1.0%) (28/2899). The relative risk was 3.02 (95% CI 1.2-7.7; p= .04). In the interventional cohort, there were 7280 women, with 114 (1.6%) cases of PPRoM. The prevalence of PPRoM in the high risk group who were treated with aspirin was 1.8% (14/766) compared to 1.5% (100/6516) in the low risk group (p= .54). The prevalence of PPRoM in high risk patients in the observational group (who did not receive aspirin) compared with the high risk patients in the interventional group (who were treated with aspirin) was not statistically significant (p= .31).Conclusions: PPRoM is significantly associated with a description of high risk for ePET; although, this algorithm is not a good screening tool for predicting PPRoM. Aspirin treatment of women deemed high risk for ePET is safe in the context of PPRoM and there may be some reduction in prevalence of PPRoM in treated high risk women; although, this study was not powered to demonstrate a small reduction in the prevalence of PPRoM. The findings merit further investigation through a larger prospective study with adequate sample size.