P21.06: Polyhydramnios in isolated oral cleft pregnancies: incidence and outcome in a retrospective study

Objectives Oral clefts (OC's) are amongst the most prevalent congenital malformations. Although polyhydramnios theoretically can be observed with OC's due to swallowing difficulties, yet information on the incidence is lacking. In general pregnancies the incidence of polyhydramnios is 1‐2%, of which 50‐60% are idiopathic. This study describes the incidence and consequences of polyhydramnios in isolated OC pregnancies. Methods Prenatally diagnosed OC's from 2007 until 2014 were reviewed. They were classified isolated if no associated structural, chromosomal or syndromal anomalies were diagnosed. Polyhydramnios was defined as AFI >P95 or SDP ≥8 and considered idiopathic if no other anomalies, diabetes, macrosomia or TORCH were seen. Pediatric follow up was obtained until a median of 3.5 years. Incidence of polyhydramnios was determined in isolated OC's, and the outcome of these cases was compared to normal amniotic fluid cases. Subgroup analysis was performed to assess whether a polyhydramnios in cases that were prenatally classified as isolated, increased the risk for finding any associated syndromes after birth. Results A total of 354 OC cases were identified, of which 241 (68%) were isolated. An idiopathic polyhydramnios was observed in 15/230 (6.5%) ongoing pregnancies with an isolated OC. Palate involvement was significantly (p = 0.03) more present in cases with polyhydramnios (13/15; 87%) than in those without (125/215; 58%). Pregnancy outcome, neonatal and pediatric follow up were not significantly different for cases with polyhydramnios. Subgroup analysis of cases prenatally classified as isolated, but diagnosed with other anomalies postpartum (n = 27), showed 1/27 (3.7%) idiopathic polyhydramnios; not significantly different from the incidence in cases that remained isolated (6.5%). Conclusions Incidence of idiopathic polyhydramnios in isolated OC pregnancies is 6.5%. Polyhydramnios is a marker for palate involvement in fetuses with an OC. If isolated at prenatal assessment, a polyhydramnios does not increase the risk of associated anomalies postpartum.