This is amazing and somewhat surprising, at least to me. When I saw the title of this article, Low-dose aspirin for the prevention of preterm delivery in nulliparous women with a singleton pregnancy (ASPIRIN): a randomised, double-blind, placebo-controlled trial. I scanned over the methods and read the results, expecting to see yet another article with a null result. Maybe I am getting cynical but the idea that you could find a way to improve perinatal outcomes in the developing world at an affordable price seemed just inherently unlikely.
How wrong I was! After seeing the results I rushed back to the methods and read in much more detail. In seven sites in 6 countries (two in India and one each in the Democratic
Republic of the Congo, Guatemala, Kenya, Pakistan, and Zambia) 12,000 nulliparous women with singleton pregnancies were enrolled between 6 and 14 weeks of gestation and received 81 mg of aspirin or a placebo every day until they reached 37 weeks.
Preterm birth decreased from 13.1% with placebo to 11·6% with aspirin (RR 0·89 [95% CI 0·81 to 0·98]). There were also reductions in perinatal mortality (0·86 [0·73–1·00]), fetal loss (0·86 [0·74–1·00]), early preterm delivery (<34 weeks; 0·75 [0·61–0·93]), and delivery before 34 weeks with hypertensive disorders of pregnancy (0·38 [0·17–0·85]). Other adverse maternal and neonatal events were similar between the two groups.
I can’t see any real downside to introducing this intervention everywhere in low- and middle-income countries, other studies in multiple pregnancies are needed, and among singletons, a comparison with higher doses is required. I also don’t understand why this should work in nulliparous women, but not in multipara, so either trials in multiparous women should be performed, or there is some reason which I don’t understand to not do so.
On the maternal side, there was a small reduction in maternal hypertensive disorders, and no clear adverse impact.
A relative reduction of 14% in perinatal mortality, from 54/1000 to 46/1000 is an enormous change in mortality, with a potential to save hundreds of thousands of lives every year.
Even writing that makes me feel a bit humble; perinatal mortality of 54 per 1000, that is more than 5%! A small reduction in that mortality is a huge potential impact around the world.
I must, at this point, feel grateful to the sponsors of this study which was funded by the NIH. A study which might well have no real impact in the USA, but which was funded by the NICHD, and includes as one of its authors, almost hidden among the others the amazing Wally Carlo. This study is one reason to continue to hold in high esteem the principles on which the USA was founded, and its profile around the world. Even if these days it is hard to believe that those principles are being pursued, this study is proof that even in the heart of darkness there continues to beat a great light.
As you say, it does seem too good to be true. Every woman, globally, needs a pill? I think that for many independent statisticians, and maybe also HTA, an odds ratio that does not cross 1.00 (but lands on it) strictly is not significant….. It needs replication & amalgamating with total literature.