Risk factors and maternal outcomes following preterm premature rupture of membrane in the second trimester of gestation.

Purpose: To characterize the population of women who underwent mid-trimester preterm premature rupture of membrane (PPROM) in a country where mid-trimester abortions are legal and available.
Methods: A retrospective cross-sectional cohort study was conducted at a tertiary referral hospital, during 2013-2016. Mid-trimester defined as gestational age 13 + 0 to 23 + 6 weeks. Rupture of membrane was defined by documentation of fluid passing through the cervix on sterile speculum examination, and a positive Nitrazine (Bristol-Myers Squibb, Princeton, NJ) or erning test. All records were evaluated for medical history, laboratory data, postnatal examination, and autopsy findings, and a database was constructed.
Results: A total of 61 women were hospitalized for mid-trimester PPROM during the study period. Mean maternal age was 32 ± 5.98, range 20-45 years old. The majority (50, 82%) of patients decided to terminate their pregnancy before reaching the limit of viability at 24 weeks gestation. The overall prognosis of pregnancies reaching term was better than expected, with six (9.8%) patients delivering live babies and four of them born at term (36 ± 5 to 40 ± 6 weeks gestation), all after PPROM following amniocentesis or selective fetal reduction. A total of 60% of women with hypothyroidism had unbalanced TSH levels above 4.0 mIU/L prior to their pregnancy. A notable number of women (15, 24.6%) had PPROM following a pregnancy achieved by assisted reproductive technology (ART).
Conclusions: Most women with diagnosed mid-trimester PPROM opted for pregnancy termination before the limit of viability when granted the choice. Possible risk factors for early PPROM are unbalanced hypothyroidism and ART. PPROM following amniocentesis can in some cases reseal and reach term, suggesting conservative treatment is a reasonable management for those cases.