Background: Recent studies suggest that low-dose acetylsalicylic acid (ASA) can lower pregnancy-associated morbidity.
Methods: This review is based on pertinent publications that were retrieved by a selective search in PubMed, with special attention to systematic reviews, metaanalyses, and randomized controlled trials.
Results: Current meta-analyses document a reduction of the risk of the occurrence of pre-eclampsia (RR 0.85, NNT 50), as well as beneficial effects on the rates of preterm birth (RR 0.80, NNT 37), fetal growth restriction (RR 0.82, NNT 77), and perinatal death (RR 0.79, NNT 167). Moreover, there is evidence that ASA raises the rate of live births after a prior spontaneous abortion, while also lowering the rate of spontaneous preterm births (RR 0.89, NNT 67). The prerequisites for therapeutic success are an adequate ASA dose, early initiation of ASA, and the identification of women at risk of pregnancy-associated morbidity. Side effects of treatment with ASA in this patient group are rare and mainly involve bleeding in connection with the pregnancy (RR 0.87, NNH 200).
Conclusion: ASA use during pregnancy has benefits beyond reducing the risk of pre-eclampsia. The indications for taking ASA during pregnancy may be extended at some point in the future; at present, in view of the available evidence, it is still restricted to high-risk pregnancies.