Serum group II phospholipase A(2) levels during menstrual cycle and pregnancy.

The purpose of this study was to evaluate the circulating group II phospholipase A(2) (PLA(2)-II) levels during normal menstrual cycle and to assess alterations in maternal circulating PLA(2)-II concentrations during pregnancy and at puerperium. Circulating serum PLA(2)-II concentrations were compared between 38 nonpregnant women with normal menstrual cycle (15 at menstrual phase, 11 at follicular phase, and 12 at luteal phase), 61 normal pregnant women (13 in the first trimester, 12 in the second trimester, and 36 in the third trimester), and 14 normal postpartum women at 5th puerperal day. Serum PLA(2)-II concentrations were also measured in 11 patients with threatened premature labor. Maternal and fetal serum PLA(2)-II levels before and after delivery were made to determine differences in 11 neonates delivered vaginally and 11 neonates delivered by elective cesarean section. Serum PLA(2)-II level was measured with an immunoradiometric assay. Serum PLA(2)-II concentrations at luteal phase were significantly lower than those at menstrual or follicular phase (p< 0.05). There was no significant difference for PLA(2)-II levels between first trimester and menstrual phase or follicular phase. There were no significant differences among three trimesters during pregnancy. There was no significant difference in serum PLA(2)-II levels between normal pregnant women and patients with threatened premature labor. Labor stress did not affect both maternal and fetal serum PLA(2)-II concentrations. There was also no significant difference for circulating PLA(2)-II levels between maternal and fetal serum. Interestingly, serum PLA(2)-II concentrations in postpartum women were significantly higher than those in normal pregnant women (p<0.05). These results suggest that a regulatory mechanism of PLA(2)-II may exist during the normal menstrual cycle and at puerperium.