Benefits and risks of low molecular weight heparin use on reproductive outcomes: A retrospective cohort study

Low molecular weight heparin (LMWH) has been given to reproductive-age women with various indications. This study aims to assess the benefits and risks of such use.

We retrospectively reviewed data (n = 204) between Jan 2016 and May 2019. Logistic regression analysis was conducted to evaluate the correlation between indications and reproductive outcomes.

LMWH use had higher odds of live birth in women less than 30 years of age (OR: 4.98; 95% CI = 1.13-21.98; p = 0.034) and with protein S deficiency (OR: 3.90; 95% CI = 1.77-8.59; p = 0.001). For the subgroup of recurrent pregnant loss, LMWH use was only advantageous to women with protein S deficiency (OR: 2.45; 95%:1.01-5.97; p = 0.048). Risks such as preterm delivery, small-for-gestational-age, placental abruption, antepartum/postpartum hemorrhage were not significantly increased among subgroups. Women treated with LMWH and who had successful live births (n = 171) had a slightly increased risk of postpartum hemorrhage compared to controls (n = 8058) during this period in our institution (2.9% vs 1.2%, p < 0.001).

LMWH administration produces a higher chance of live-birth to women younger than 30 years of age or with protein S deficiency. However, risk of postpartum hemorrhage is increased.