Low-dose aspirin prevents pregnancy-induced hypertension and pre-eclampsia in angiotensin-sensitive primigravidae.

The possibility of preventing pregnancy-induced hypertension (PIH) and pre-eclampsia in primigravidae by suppressing production of thromboxane A2 with low-dose aspirin was investigated in a randomised, placebo-controlled, double-blind trial. 46 normotensive women at 28 weeks' gestation, judged to be at risk of PIH or pre-eclampsia because of an increased blood-pressure response to intravenously infused angiotensin II, were studied. 23 women received 60 mg aspirin daily, and the same number received matching placebo until delivery. In the placebo group PIH, pre-eclampsia, and eclampsia developed in 4, 7, and 1 cases, respectively, whereas only 2 women in the aspirin group had mild PIH. There were no adverse effects of treatment in mothers or infants. Low-dose aspirin may restore prostacyclin/thromboxane imbalance, previously suggested as an important aetiological factor in PIH and pre-eclampsia.