Raised alpha-fetoprotein levels in amniotic fluid and maternal serum associated with distension of the fetal bladder caused by absence of urethra.

Raised alpha-fetoprotein concentrations were found at 29 and 30 weeks' gestation in the amniotic fluid and maternal serum of a woman who presented in her seventh pregnancy with apparent polyhydramnios. The fetus had multiple abnormalities including gross distension of the bladder resulting from absence of the urethra, intestinal artresia, and a congenital heart defect.