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.