Lower incidence of hypertensive complications during pregnancy in patients treated with low-dose aspirin during in vitro fertilization and early pregnancy

Abstract

BACKGROUND: The use of aspirin during in vitro fertilization (IVF) has been investigated for its effect on pregnancy rates after IVF. In most of these studies, aspirin administration was then prolonged throughout the first trimester of pregnancy. By inhibiting vasoconstriction, the use of low-dose aspirin in the first trimester could influence placentation and therefore prevent or delay development of hypertensive pregnancy complications, such as pregnancy-induced hypertension (PIH) and pre-eclampsia (PE). METHODS: This study involved the follow-up by questionnaires and hospital records of patients with an ongoing pregnancy in a prospective, randomized, double-blind, placebo-controlled trial on the effect of low-dose aspirin during IVF. Aspirin treatment was continued throughout the first trimester of pregnancy. The primary end-point of this follow-up study was the incidence of pregnancy complications. The original trial is registered with the Dutch Trial Register and as an International Standard Randomized Clinical Trial, No. ISRNCTM97507474. RESULTS: There were 54 patients who had ongoing pregnancies in the original trial; 90.7% returned the questionnaire and all Dutch hospital records were retrieved. A significant difference was found in the incidence of hypertensive pregnancy complications: 3.6% in the aspirin group and 26.9% in the placebo group (P < 0.05), resulting in numbers-needed-to-treat (NNT) of 10.3 to prevent hypertensive complications in one pregnancy after IVF treatment. CONCLUSIONS: The incidence of hypertensive complications was significantly lower in the group of women treated with low-dose aspirin throughout IVF treatment and first trimester of pregnancy. These results suggest a potential benefit of low-dose aspirin during IVF and first trimester to prevent hypertensive pregnancy complications. The findings justify further investigation in placebo-controlled randomized trials.