Congenital chloride diarrhoea: a prenatal differential diagnosis of small bowel atresia.

We compared ultrasound findings and pre- and postnatal clinical signs in 8 patients with congenital chloride diarrhoea and 14 with small bowel atresia diagnosed in 1977-1991 in order to evaluate the possibility of a prenatal distinguishing diagnostic sign. In the patients with congenital chloride diarrhoea the pregnancy was complicated by marked polyhydramnios, the symphysis-fundus distance exceeded + 2 SD before gestational week 31 and the fetus displayed normal peristalsis in extensively dilated intestines and the "frog position". In the patients with small bowel atresia the symphysis-fundus distance was normal before gestational week 31 and the fetus displayed increased peristalsis in a few dilated intestinal loops.