Pancreatic phospholipase A2 in human serum during pregnancy is within the normal range. In the amniotic fluid, the amount of immunoreactive pancreatic phospholipase A2 increases from 1.3 microgram/l at 16 weeks to 2.9 micrograms/l near term, but does not correlate with PLA2-activity. Meconium-stained amniotic fluid had highly elevated pancreatic, but not kinetic, PLA2. The fetal pancreas and its high PLA2-content may contribute to the progressive increase in uterine activity during human pregnancy.