how does heparin help treat recurrent miscarriages

Women with URM in first trimester of their pregnancy who had already been under the treatment of LMWH (either enoxaparin or tinzaparin) or no treatment, aged between ≥ 18 and < 35 years, in our tertiary teaching hospital between March 2010 and January 2012 were followed till the end of their pregnancy.

All women had normal results for parental karyotyping, hysterosalpingography or hysteroscopy, thyroid function and glucose tolerance tests, serum prolactin, homocysteine levels and mid-luteal progesteron level. All included patients have been screened for thrombophilia, all investigations were checked and patients with luteal phase defects, infections represented namely by Mycoplasma and Chlamydia, pathological levels for antinuclear factor or antiphospholipid antibodies (anticardiolipin IgG, IgM antibodies or lupus anticoagulant) and with hereditary thrombophilia patterns protein C, S and antithrombin deficiencies and presence of factor V Leiden mutation, prothrombin (G20210A) mutation and homozygosity for MTHFR (C677T) were not included to study.

Women with cardiovascular disease, bleeding diathesis, previous thromboembolic phenomena, diabetes mellitus, vaginal bleeding, multiple pregnancy, smoking, morbid obesity and presence of contraindication for anticoagulant therapy were also excluded.

For each group (tinzaparin, enoxaparin and control group) fifty patients with unexplained recurrent pregnancy loss were included to the study. Totally 150 patients were followed throughout their pregnancy. Only the patients, who have used standardized dosage of the study medication of either 4000 IU/day in enoxaparin group or 3500 IU/day in tinzaparin group when fetal viability was confirmed by ultrasonography at 6 weeks of gestation were followed till the end of their pregnancy. Women receiving LMWH had been tought to self-inject subcutaneously in the anterolateral abdominal wall on the right and left sides alternatively. Adherence was confirmed with telephone interview biweekly for the first 4 weeks. Prenatal follow-up was obtained to assess fetal growth, fetal well-being and drug side effects for every 4 weeks until 32 weeks, every 2 weeks between 32-36 weeks and then weekly until delivery if pregnancy reaches to term. All pregnant women underwent genetic screening in the first trimester of pregnancy. Treatment was continued until abortion or delivery. Before planned induction of labor or elective cesarean delivery, LMWH treatment were ceased to prevent intraoperative hemorrhage.