PLATELET SENSITIVITY TO PROSTAGLANDIN E(1) INHIBITION IS REDUCED IN PREECLAMPSIA BUT NOT IN NONPROTEINURIC GESTATIONAL HYPERTENSION

Objective Platelet aggregometry was used to discriminate platelet sens itivity to prostaglandin E(1) (PGE(1)) inhibition, to evaluate whether platelet behaviour in pre-eclamptic women was different in this respe ct than from that in nonproteinuric hypertensive women. Methods The am ount of PGE(1) required to inhibit in vitro platelet aggregation induc ed by arachidonic acid was determined in samples from 60 women: 20 non pregnant controls, 20 women with normal pregnancies, 10 women with ges tational hypertension and 10 with pre-eclampsia. Results The response to arachidonic acid was similar among the four groups. Amounts of PGE, necessary to inhibit platelet aggregation were significantly higher i n normal pregnant women compared with nonpregnant controls (P < 0.001) . Platelets from pre-eclamptic women required significantly higher con centrations of PGE(1) to inhibit aggregation than the other groups stu died (P < 0.001). However, there was no significant difference between normal and nonproteinuric hypertensive pregnant women. Conclusions Ou r findings support the notion that increased platelet reactivity durin g late pregnancy is exacerbated in pre-eclamptic women but not in nonp roteinuric hypertensive women. This is in agreement with the hypothesi s that pre-eclampsia and gestational hypertension are different condit ions. Prospective studies are required to confirm if this simple test may be useful in the early identification of pregnant women at risk fo r pre-eclampsia.