[Differential diagnosis of a polyhydramnion in hyperprostaglandin E syndrome: a case report]

A polyhydramnion is diagnosed in 0.4 to 3.3 % of all pregnancies. The most common causes of increased amniotic fluid include maternal diabetes mellitus, fetal malformations and chromosomal aberrations, twin-to-twin transfusion syndrome, rhesus incompatibility syndrome, and congenital infections. After exclusion of other etiologies for polyhydramnion, the very rare, autosomal-recessive transferred hyperprostaglandin E syndrome (HPS) has to be considered.

We report on a 31-year-old women who visited our obstetrical outpatient clinics at 22 + 4 weeks of gestation for prenatal ultrasound scanning and amniocentesis. This, the patient's third pregnancy had been without complications so far. She had delivered two children before, one of them bearing the HPS. The women herself suffered from epilepsy. At 26 + 0 weeks of gestation the pregnancy was complicated by a polyhydramnion requiring serial amniocentesis for reducing amniotic fluid load. Among others, her amniotic fluid was analyzed for chloride concentration and for genetic aberrations regarding HPS. Serological investigations and an oral glucose tolerance test (oGTT) were performed.

Amniocentesis revealed a normal chromosomal pattern. The oGTT demonstrated values in the normal range. Serological investigations regarding TORCH infections were without pathological findings. The chloride concentration was highly increased in the amniotic fluid, which is suspicious for HPS. Finally, molecular analysis proved an NKCC2-mutation responsible for HPS. A cesarean section was performed at 33 + 3 weeks of gestation.

If HPS is suspected to be the cause of polyhydramnions, the chloride concentrations in the amniotic fluid and molecular analysis for HPS should be performed. Interdisciplinary care, diagnostics and therapy in an experienced perinatal center are essential for an optimal outcome of the pregnancy and the newborn infant.