Heparin Not Always Advisable for Recurrent Miscarriage
By Kathryn Doyle
Women with multiple unexplained miscarriages are sometimes advised to take daily injections of heparin, but a new study finds the drug doesn't appear to increase live-birth rates.
For women with clotting disorders, low-molecular-weight heparin does help protect pregnancies.
"Research published about 15 years ago showed that such women benefit substantially from heparin," Dr. Ekkehard Schleussner of Friedrich Schiller University Hospital and Dr. David Petroff of the University of Leipzig told Reuters Health in a statement.
"That's when the hope emerged that it could benefit other women with pregnancy loss," they wrote.
Later, doctors began prescribing heparin for women with recurrent pregnancy loss even without a clotting disorder.
The new study included 449 pregnant women with at least two consecutive miscarriages or one late-term miscarriage at 14 clinics in Germany or Austria.
Between the first and second months of pregnancy, the women were randomly assigned to take either folic acid multivitamins or folic acid multivitamins plus daily heparin injections for up to six months of pregnancy.
At the six-month point, 191 pregnancies in the heparin group and 188 pregnancies in the vitamin-only group were still intact, which is not a meaningful difference, Schleussner and Petroff and colleagues reported in the Annals of Internal Medicine.
About 86% of women in both groups had a live birth.
"When 'recurrent' is defined as two or more (pregnancy) losses, up to 3% of fertile couples fall into this category, whereas 1% of women experience three or more pregnancy losses," said Dr. Saskia Middeldorp of the University of Amsterdam who was not part of the new study.
"Heparin has an important role in embryonic implantation and placentation," said Dr. Offer Erez of Soroka University Medical Center in Beer Sheba, Israel, who was also not part of the study.
But at least four previous trials also found that low-molecular-weight heparin didn't seem to help maintain pregnancy for women with recurrent loss, according to Dr. Jean-Christophe Gris of University Hospital in Nîmes, France, who wrote an editorial accompanying the new results.
Due to the bleeding risk, heparin is discontinued before birth, Petroff noted.
"This is a long and expensive treatment, which is usually not covered by insurances in most countries," Gris said. "Each injection costs around $30, the treatment lasting around 220 days, thus 6,600 US dollars."
Women with recurrent early miscarriages who do not test positive for clotting problems - that is, most women with recurrent pregnancy loss - should not be prescribed heparin, but if the tests are positive, they should be treated with a combination of heparin and aspirin, he said.
"Pregnant women who have experienced recurrent miscarriage are very motivated to do whatever it takes to increase the chance of having a baby," Middeldorp said.
But heparin is only appropriate for certain women with antiphospholipid syndrome, which can be confirmed by two blood tests 12 weeks apart, she said.
"Heparin for women with unexplained recurrent miscarriage is proven to not be effective, it is expensive, and it causes harm," she said.
SOURCE: https://bit.ly/1DPQvUk
Ann Intern Med 2015.
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