Heparin use may prevent pre-eclampsia onset

Thromboprophylaxis with low molecular weight heparin (LMWH) appears to protect against the onset of superimposed pre-eclampsia, independently from aspirin use, reports a recent study. 

A team of investigators retrospectively selected women diagnosed with chronic hypertension from an electronic database from January 2019 to January 2024. The occurrence of adverse pregnancy outcomes described as the onset of pre-eclampsia and/or foetal growth restriction was the primary endpoint. 

In total, 219 pregnant women with chronic hypertension (mean age 36.1 years) were included in the analysis. Before pregnancy, the BMI of participants was 27.8 kg/m2. Of these, 22.9 percent had pre-eclampsia and 9.6 percent had foetal growth restriction. 

In the first trimester, 80.1 percent of women received low-dose aspirin 100 mg, and 16.7 percent received LMWH (at prophylactic doses according to BMI). 

The rate of pre-eclampsia did not differ significantly between patients taking aspirin or not (21.3 percent vs 25 percent). However, pre-eclampsia rates were significantly lower among patients who were taking vs not taking LMWH as thromboprophylaxis (8.8 percent vs 25 percent; p=0.04). Of note, foetal growth restriction occurrence did not differ according to prophylaxis use. 

In addition, high resistance at uterine arteries Doppler velocimetry at 24–25 weeks of gestation showed an association with pre-eclampsia onset (51 percent vs 11.9 percent; p<0.001) and foetal growth restriction (18.2 percent vs 6.9 percent; p=0.04).