Clinical Outcome and Safety of Amnioreduction in Singleton Pregnancies with Severe Polyhydramnios
Laia Grau1, Míriam Pérez-Cruz2,3,4, Mar Bennassar1,5
1BCNatal - Fetal Medicine Research Center (Hospital Clínic and Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain.
Introduction:
Severe polyhydramnios is associated with fetal anomalies and adverse perinatal outcomes. The safety of amnioreduction in singleton pregnancies remains unclear. We aimed to evaluate pregnancy outcomes and procedure-related complications of amnioreduction in singleton pregnancies with severe polyhydramnios, excluding other invasive procedures apart from diagnostic amniocentesis.
Methods:
Retrospective analysis of amnioreduction procedures performed in 40 singleton pregnancies at a fetal therapy referral center (2013-2024). Inclusion criteria were severe polyhydramnios (defined by an Amniotic Fluid Index ≥35 cm) associated with maternal intolerance and/or short cervix evaluated by ultrasound (with a cut-off <15 mm). Procedure-related complications occurring within 48 h, including premature rupture of membranes, placental abruption, chorioamnionitis, preterm delivery below 37 weeks, and fetal demise were recorded. Maternal and pregnancy data, technical procedural characteristics, and perinatal outcomes were compared between complicated and uncomplicated procedures.
Results:
In 90% of the cases, a recognizable etiology for polyhydramnios was identified, with fetal structural anomalies being the most frequent cause, accounting for 62.5% of cases. Overall complication rate was 8.8%, including 3 placental abruptions and 2 cases of premature rupture of membranes. Complicated procedures were associated with earlier delivery (31.9 ± 3.7 vs. 36.8 ± 1.9 weeks, p = 0.016) and shorter procedure-to-delivery interval (8.6 ± 14.7 vs. 33.4 ± 16.4 days, p = 0.003). Repeated amnioreductions did not increase complication rates. No significant association was observed between pregnancy- or amniodrainage-related variables - including the number of amnioreduction sessions - and the occurrence of complications.
Conclusion:
These findings support that amnioreduction performed by highly trained personnel following a standardized protocol is a safe intervention in singleton pregnancies complicated by severe polyhydramnios. These data may provide valuable guidance in prenatal counseling for cases in which prolonging gestation is crucial due to fetal structural anomalies.
