News items Anticoagulant drug cannot prevent miscarriage

1 June 2023

The use of an anticoagulant by pregnant women with an inherited increased clotting tendency does not lead to fewer miscarriages. That's according to a study by researchers from Radboudumc, Amsterdam UMC and Warwick University. Daily administration of injections of the anticoagulant heparin does not improve pregnancy outcomes. Partly because of the side effects of heparin, the researchers recommend immediate discontinuation of prescribing these drugs to prevent miscarriages. The study was published today in The Lancet.

The AlIFE2 study is an international study set up by researcher and gynecologist Mariëtte Goddijn (Amsterdam UMC) and internist Saskia Middeldorp (then Amsterdam UMC, now Radboudumc). The study was conducted in collaboration with hospitals in the Netherlands, the United Kingdom, Belgium, the United States and Slovenia.

Women who had suffered two or more miscarriages and had an inherited clotting tendency (called thrombophilia) could participate. A draw determined whether or not they would use an anticoagulant (LMWH, a form of heparin). Mariëtte Goddijn: 'Women with an increased clotting tendency are slightly more likely to miscarry. Now it turns out that prescribing heparin does not help with this. Treatment guidelines should be adjusted.'


The researchers show that use of heparin does not affect the course of pregnancy. The percentage of live births was almost the same in both study groups: 71.6% in the group that used the anticoagulant medication and 70.9% in the group with standard care. Anticoagulants are still prescribed in these women worldwide today. Saskia Middeldorp: 'Now that we know the outcome of this study, this can be discouraged. This prevents unnecessary treatment: women no longer need to inject themselves daily for long periods of time.'

Big savings

Also, women who have had multiple miscarriages no longer need to be tested for hereditary thrombophilia. This not only leads to big savings in the cost of diagnosis and treatment of women with repeated miscarriages. Also because of the known side effects of heparin such as bruising and allergic skin reactions, the researchers recommend immediate discontinuation of prescribing these drugs to prevent miscarriages.


The study's findings may be reassuring for women with hereditary thrombophilia who have experienced multiple miscarriages. Middeldorp: "Our study shows that with standard antenatal care, just over 70% of these women will have a live-born child. That percentage was the same after heparin use in this group of women. Expensive tests and burdensome drug use are thus a thing of the past.

About the publication

This study was published in The Lancet: Heparin for women with recurrent miscarriage and inherited thrombophilia: an international multicentre randomised controlled trial (ALIFE2) – Siobhan Quenby, Katie Booth, Louise Hiller, Arri Coomarasamy, Paulien G. de Jong, Eva N. Hamulyák, Luuk J. Scheres, Thijs F. van Haaps, Lauren Ewington, Shreeya Tewary, Mariëtte Goddijn, Saskia Middeldorp, on behalf of ALIFE2 block writing committee and ALIFE2 Investigators.

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Pauline Dekhuijzen

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