Oligohydramnios in Women with Preterm Prelabor Rupture of Membranes and Adverse Pregnancy and Neonatal Outcomes

OBJECTIVE: To determine the association between the presence of oligohydramnios, determined as an amniotic fluid index ≤ 5 cm and the intra-amniotic inflammatory response, fetal inflammatory response and neonatal outcomes in actively managed preterm prelabor rupture of membranes (PPROM). METHODS: Women with singleton pregnancies complicated by PPROM at a gestational age of between 24+0 and 36+6 weeks were included in the study. Ultrasound assessments of the amniotic fluid index and evaluation of the amniotic fluid interleukin (IL)-6 levels were performed at admission. The umbilical cord blood IL-6 levels were evaluated after delivery. RESULTS: In total, 74 women were included. The women with oligohydramnios did not have different amniotic fluid IL-6 levels [with oligohydramnios: median 342 pg/mL, interquartile range (IQR) 110-1809 vs. without oligohydramnios: median 256 pg/mL, IQR 122–748; p = 0.71] or umbilical cord blood IL-6 levels (with oligohydramnios: median 8.2 pg/mL, IQR 3.8–146.9 vs. without oligohydramnios: median 5.9 pg/mL, IQR 2.1–27.9; p = 0.14) than those without oligohydramnios. No association between oligohydramnios and neonatal morbidity was found. A correlation between the amniotic fluid index and the interval from rupture of membranes to amniocentesis was observed (rho = −0.34; p = 0.003). CONCLUSION: The presence of oligohydramnios is not associated with an adverse outcome in actively managed PPROM in singleton pregnancies in the absence of other complications.