Two Patients with fetal ascites and different types of cystic fibrosis

Aim: Cystic fibrosis (CF) is an autosomal recessive disorder, leading to organ dysfunction and decreased life expectancy. Prenatal diagnosis is based on either the family history or suspicious ultrasound findings such as echogenic bowl indicating genetic investigation of the parents. Within one year we were confronted with two patients with fetal ascites partly due to associated anomalies or to unexpected cystic fibrosis.

Results: Case 1) A 28-year-old primigravida was referred at 21 weeks due to pyelectasis. At 26 weeks polyhydramnios and fetal ascites were present. Torch serology was negative, amniocentesis revealed a normal karyotype, but multiplex amplification of fetal cells showed a CFTR-Mutation F508del and R1162X. Subsequent testing of the parents revealed a maternal CFTR-Mutation R1162X and a paternal F508del Mutation and a 5T-allel (compound constellation). Cesarean delivery was performed at 29 weeks of a girl of 1820 g. Additional findings were anal atresia, common vagina and urethra and hypoplasia of the gall bladder. After surgical intervention and a long stay within our intensive care unit the girl developed fine.

Case 2) A 18-year-old primigravida was referred at 30 weeks due to a dilated bowl and ascites. Amniocentesis revealed a normal female karyotype and a homozygous DeltaF508-Mutation which was also confirmed in both heterozygous parents. Cesarean delivery was performed at 38 weeks. Due to meconium ileus the girl received an intestinal resection. Up to now, the child developed uneventfully.

Conclusion: Although rarely described in the literature, fetal ascites may accompany fetuses with prenatal CF. In the differential diagnosis independent malformations (case 1) and bowl obstruction (case 2) may play a pathogenic role, but even if malformations are present this should not rule out additional CF.

Fetal ascites should thus indicate prenatal testing for CF.