Reduced platelet-activating factor-acetylhydrolase activity in maternal plasma obtained from normotensive pregnant women destined develop pregnancy-induced hypertension

Objective: To elucidate whether plasma platelet-activating factor-acetylhydrolase (PAF-AH) activities in pregnant women who are destined to develop pregnancy-induced hypertension (PIH) are different from those in normotensive pregnant women. Study Design: We evaluated plasma PAF-AH activity in 18 nonpregnant normotensive women. We also evaluated longitudinally plasma PAF-AH activity, platelet counts, and mean platelet volume (MPV) in normotensive pregnant women at 8 weeks', 20 weeks', and 30 weeks' gestation. Plasma samples were obtained from 15 patients who ultimately developed PM after 35 weeks' gestation (PM, subgroup), and 11 patients who remained normotensive during pregnancy (non-PIH subgroup). Results: PAF-AH activity in nonpregnant women was significantly higher (p < 0.05) than that in the non-PIH pregnant subgroup at 8 and 20 weeks' gestation. PAF-AH activity at 8, 20, and 30 weeks' gestation in the PIH subgroup was significantly lower (p < 0.03) than that in the non-PIH group at each gestational week. PAF-AH activity in the PIH subgroup was positively correlated with platelet counts (p < 0.001) and negatively correlated with MPV (p < 0.02). Conclusions: Plasma PAF-AH activity is low by the first trimester in normotensive pregnant women who are destined to develop PIH, and this decreased enzyme activity may be related to platelet activation and consumption.