Contributed by: Anuolu Bank-Oni, PharmD, CDE, BCGP
Babies delivered before the 37th week of pregnancy have higher rates of infant mortality. This is especially true for infants born in low- and middle-income countries (LMICs). Prior studies have found that pregnant women who receive low-dose aspirin daily are less likely to deliver their babies prematurely, particularly when the medication is started before the fourth month of pregnancy.
An article recently published in The Lancet reviewed the results of a randomised, double-masked, placebo-controlled trial. The goal of the study was to determine whether 81 mg of aspirin reduces the risk of premature delivery in women with no previous births (i.e. nulliparous). Between March 23, 2016 and April 11, 2019, approximately 12,000 nulliparous pregnant women in six LMICs received daily doses of either 81 mg of aspirin or placebo. Enrolled participants were early in their pregnancy (at least 6 weeks) and received the study medication until either delivery or the ninth month (37th week) of pregnancy.
Low-dose Aspirin Reduced the Risk of Preterm Birth
The results of the study showed that when compared to placebo, low-dose aspirin reduced the rates of preterm delivery (13.1% vs 11.6%; p=0.012), perinatal mortality (53.6% vs 45.7%; p=0.048), and foetal death (between the fourth month of pregnancy and 7 days postpartum: 60.8% vs 52.1%; p=0.039). Both treatment groups had similar rates of low birth-weight and other adverse effects. Some of these adverse effects include bleeding (gastrointestinal and vaginal), haemorrhage (antepartum and postpartum), anaemia, congenital anomaly, and maternal death.
The authors noted that an optimal dose of aspirin for this patient population needs to be determined, as higher doses may provide additional benefits. Also noted is the fact that this is the first large randomised-controlled trial to investigate this theory and the results confirm the findings from previous studies.
In summary, these results suggest that aspirin should be considered as a treatment option to prevent preterm birth in pregnant women.
References:
- Hoffman MK, et al. Low-dose aspirin for the prevention of preterm delivery in nulliparous women with a singleton pregnancy (ASPIRIN): a randomised, double-blind, placebo-controlled trial. The Lancet, 395(10220), pp.285-293. doi: 10.1016/S0140-6736(19)32973-3