Fetal pepsinogens in human amniotic fluid.

The presence of group I (Pg I) and group II (Pg II) pepsinogens was determined in 59 samples of human amniotic fluid between 11 and 40 weeks of gestation. Pg I was present in all of the samples, while Pg II was present only in samples of gestational age 32 weeks or older. No differential pattern of the fractions was present, although the first fraction of Pg I was not present in any of the samples. The sequential appearance of Pg I and Pg II suggests their fetal origin and that the synthesis of Pg I by fetal gastric mucosa may precede that of Pg II, thus serving as a potential marker of fetal maturity.