Serum group I pepsinogens during pregnancy.

Serum group I pepsinogens (PG I) values were determined by a radioimmunoassay method in blood drawn from women at different times during pregnancy, at delivery, and 4 days after delivery. They were divided into five groups according to sampling time: group I, 0-14 weeks of pregnancy; group II, 15-27 weeks; group III, 28-40 weeks; group IV, at delivery; and group V, 4 days after delivery. No significant difference between the mean serum PG I in the various groups was found, and the mean PG I value in each group was of the same magnitude as previously found in non-pregnant controls. Since serum PG I has been reported to be positively correlated with gastric acid and pepsin secretion, this study suggests that other factors are involved in the apparently reduced occurrence of peptic ulcer during pregnancy.