Prenatal diagnosis of meconium ileus and meconium peritonitis: Indications for cystic fibrosis testing

Introduction. More recently, the regions of increased abdominal echogenicity such as echogenic bowel, meconium ileus and meconium peritonitis have been associated with an increased prevalence of a variety of unfavourable outcomes including chromosomal abnormalities, cytomegalovirus infection, intestinal obstruction, anorectal malformations and cystic fibrosis. Earlier prenatal examinations of these severe autosomal recessive diseases had been suggested only to families with history of cystic fibrosis. Recently, systemic examination has been introduced by ultrasound with bowel hyperechogenicity where the fetus is the index case for genetic disease. Risk for cystic fibrosis with this ultrasonography findings ranges from 0-33%. Outline of Cases. Two patients are presented, aged 24 and 29 years, both primigravide. The first one had ultrasonography finding of meconium peritonitis revealed at the 37th week of gestation and the other meconium ileus revealed on ultrasonography at the 29th week of gestation. Both patients had prenatal testing of foetal blood obtained by cordocenthesis, both had normal kariotype and were negative for cytomegalovirus infection. Parental DNA testing for the 2nd patient showed that parents were not carriers for the 29 most frequent mutations. Both neonates had intestinal obstruction, underwent surgery and early postoperative course was normal. Hystopathological finding suggested a possibility of cystic fibrosis for the 1st patient, but parents did not want to be tested and for the 2nd one congenital bowel stenosis as a cause of intestinal obstruction. Conclusion. Ultrasonographic echogenic bowel is an indication for invasive procedures for foetal blood testing for chromosomal abnormalities, congenital infections and parental testing for cystic fibrosis. Only if parental heterozygosity is proven foetus should be tested.