Skip to content

    Health & Pregnancy

    Font Size
    A
    A
    A

    Blood Thinner Doesn’t Prevent Miscarriages: Study

    By
    WebMD Health News

    July 25, 2014 -- Injected blood thinners don’t prevent pregnancy complications in women who may be prone to blood clots, a new study shows.

    Women who have had miscarriages are often given blood tests to check for genetic problems that may lead to blood clots.

    These inherited clotting problems affect about 1 in 10 people in North America, according to study researcher Marc Rodger, MD. He is a senior scientist at the Ottawa Hospital Research Institute in Canada.

    The fear is that having one of these clotting problems may cause clots to form in the placenta, choking the delivery of oxygen and nutrients to a growing baby.

    Research in the past suggested that having a clotting disorder might be tied to miscarriage, so about 15 years ago doctors began to prescribe the blood thinner heparin, which is sold under the brand names Fragmin, Innohep, and Lovenox, to help prevent them and other serious problems like preeclampsia.

    “And that led to a lot of docs prescribing this medication and a lot of patients demanding this medication, because there’s really very little that can be offered to [these] patients,” Rodger says.

    But these blood thinners may not work as well as doctors had hoped.

    Blood Thinners Not Needed?

    In the new study, which is published in The Lancet, doctors recruited 292 pregnant women who had clotting disorders confirmed by blood tests. They were also considered to be at high risk for pregnancy complications because they had a history of preeclampsia, pregnancy loss, blood clots in a leg or lung, a low-birth-weight baby, or a placental abruption, where the placenta separates from the wall of the uterus before delivery.

    Researchers randomly assigned about half the women to get daily injections of the blood thinner Fragmin. The other half didn’t get the injections. Most started the injections around the 12th week of pregnancy and continued until week 37.

    About 1 in 6 women in the study had a serious pregnancy complication during the study. Those included blood clots, high blood pressure and mild kidney failure, birth of a baby that was small for its age, or a miscarriage.

    Pregnancy Week-By-Week Newsletter

    Delivered right to your inbox, get pictures and facts on
    what to expect each week of your pregnancy.

    Today on WebMD

    hand circling date on calendar
    Track your most fertile days.
    woman looking at ultrasound
    Week-by-week pregnancy guide.
     
    Pretty pregnant woman timing contaction pains
    The signs to watch out for.
    pregnant woman in hospital
    Are there ways to do it naturally?
     
    slideshow fetal development
    Slideshow
    pregnancy first trimester warning signs
    Article
     
    What Causes Bipolar
    Video
    Woman trying on dress in store
    Slideshow
     
    pregnant woman
    Article
    Woman looking at pregnancy test
    Quiz
     
    calendar and baby buggy
    Tool
    dark chocolate squares
    Slideshow