Low-dose aspirin can reduce the number of premature births due to preeclampsia by more than 60%, a multicentre, double-blinded and placebo-controlled trial reported. The study was published in the New England Journal of Medicine in June 2017.

Aspirin achieves a significantly lower incidence of preterm preeclampsia

The trial was conducted at 13 maternity hospitals in Belgium, Italy, Israel, Greece, Spain and the United Kingdom. A total of 1,620 pregnant women at high risk of preeclampsia participated in the study. Participants were either provided with aspirin at a dose of 150mg per day or placebo. In the aspirin group, participants were prescribed the medication and they need to follow the instructions to take the drug every night from 11 – 14 weeks gestation to 36 weeks of gestation, or until the onset of labour.

Results revealed that the rates of premature birth in those taking aspirin were 1.6%, lower than the 4.3% in the placebo group. This indicates that low-dose aspirin can be considered as a prophylactic of preterm delivery for women at high risk of preeclampsia.

This paper is the latest in a series of clinical trials attesting to the benefits of low-dose aspirin in women with high risk of preeclampsia. Aspirin has a solid evidence base dating back to the mid-1980s in the prevention of preeclampsia. It has been proven to be safe when taken in mothers with no increased risk of major bleeding. Additionally, studies following up infants up to 18 months after birth revealed there are no developmental differences between mothers who took aspirin and mothers who did not.

“It is still unclear why aspirin could help prevent preeclampsia... We believe it might help the implantation of placenta and improve blood circulation,” said Dr Liona Chiu-yee Poon, associate professor in Chinese University’s (CUHK) department of obstetrics and gynaecology, also the principal investigator in this study.

However, one should note that low-dose aspirin is most effective only before 20 weeks of pregnancy as preeclampsia may set in after this time.

Study formulates new screening algorithm to detect women at high risk of preeclampsia

Preeclampsia is a condition that lies at the severe end of the hypertensive disorder spectrum in pregnancy. It obstructs adequate blood flow to the placenta which may restrict foetal growth. The disorder is a serious medical complication that may culminate in eclampsia (seizures) and multiorgan failure, resulting in maternal and foetal morbidity.

The study not just offered a definite proof that aspirin is prophylactic against preeclampsia, but also introduced an innovative screening algorithm to detect women at high risk of preeclampsia. This may further reduce the number of maternal deaths. The screening algorithm encompasses the woman’s medical history, laboratory biomarkers and demographic characteristics.

Statistics revealed that 14% of maternal deaths per year could be attributed to preeclampsia and eclampsia. A 2011 survey in China found that 5.22% of 5,869 pregnant mothers had a hypertensive disorder. Of these, severe preeclampsia made up of nearly 40%.

"Over the last ten years, we have developed new methods for assessing the risk of preeclampsia. We have applied these to identify women for inclusion in the ASPRE trial. The results show that aspirin can prevent preeclampsia in high risk pregnancies. I hope that they will alter clinical practice and improve pregnancy outcomes for mothers and their babies," expressed Professor David Wright of University of Exeter Medical School, co-author of the study. MIMS

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