Megacystis-microcolon-intestinal hypoperistalsis syndrome: the difficulties with antenatal diagnosis. Case report and review of the literature.

Megacystis on antenatal scan in female fetuses is rare and has serious diagnostic implications. We report two cases of megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) in female infants in whom antenatal scan abnormalities were identified, but the diagnosis not made until after delivery. MMIHS is a rare autosomal recessive condition which is usually lethal in the first year of life. Prenatal diagnosis is hampered by the lack of specific diagnostic findings on ultrasound and the absence of an identified genetic locus. The prenatal findings in MMIHS are reviewed and contrasted with those of other causes of lower abdominal masses on antenatal ultrasound.