Low-molecular weight heparin in patients with recurrent early miscarriages of unknown aetiology

J Obstet Gynaecol. 2008 Apr;28(3):280-4. doi: 10.1080/01443610802042688.


The aim of this randomised prospective study was to assess the efficacy of early thromboprophylaxis with low-molecular weight heparin (LMWH) in women with a history of recurrent first trimester spontaneous abortion or miscarriages without identifiable causes vs no treatment. The study comprised of 340 women with unexplained spontaneous recurrent miscarriages. Patients in group A were prescribed LMWH (Enoxaparin sodium 0.2 ml, 20 mg, once daily subcutaneously) from the time of confirmation of fetal viability by ultrasonography until 34 weeks' gestation, and folic acid tablets 0.5 mg daily until 13 weeks' gestation. Patients in group B were given folic acid tablets 0.5 mg daily until 13 weeks' gestation. Termination of pregnancy was the primary outcome. There was a significant difference in the incidence of both early (4.1% vs 8.8%) and late miscarriages (1.1% vs 2.3%) in group A than in group B, respectively. There were no differences between both groups as regards the occurrence of pre-eclampsia, placental abruption, caesarean delivery, intra-partum bleeding or ecchymosis at operative wounds. There were no differences in most of the neonatal values between both groups. However, the mean birth weight was significantly higher in group A. LMWH seems to be a safe drug and effective in significantly reducing the incidence of recurrent miscarriages of unknown aetiology when given in the first trimester and continued throughout pregnancy.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Abortion, Habitual / etiology
  • Abortion, Habitual / prevention & control*
  • Adolescent
  • Adult
  • Anticoagulants / administration & dosage*
  • Confidence Intervals
  • Dose-Response Relationship, Drug
  • Drug Administration Schedule
  • Female
  • Gestational Age
  • Heparin, Low-Molecular-Weight / administration & dosage*
  • Humans
  • Injections, Subcutaneous
  • Pregnancy
  • Pregnancy Complications / prevention & control
  • Pregnancy Outcome*
  • Pregnancy Trimester, First
  • Probability
  • Prospective Studies
  • Reference Values


  • Anticoagulants
  • Heparin, Low-Molecular-Weight