Abstract
Background
Previously, low molecular weight heparin (LMWH) has shown good anti-thrombotic effects and helped improve pregnancy outcomes for women with thrombotic diseases undergoing assisted reproductive technology (ART), prompting its use in women without thrombotic disease. However, there are few standardized medication guidelines for LMWH use in non-thrombotic patients, and it is unclear whether LMWH truly benefits pregnancy outcomes in these patients. There we want to investigate whether LMWH affects pregnancy outcomes of patients without thrombophilia undergoing ART.
Methods
A total of 3067 infertile women who were undergoing their fresh in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycle in the Reproductive Medicine Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology in 2019 were finally eligible for this retrospective cohort study, with 119 and 2948 administered with LMWH and without LMWH respectively. Clinical pregnancy rate (CPR) and the secondary outcomes include live birth rate (LBR), miscarriage rate (MR), multiple pregnancy rates (MPR), biochemical pregnancy rate (BPR) and ectopic pregnancy rate (EPR) were compared among these two groups.
Results
Before adjustment for confounders, MPR (8.4% vs. 3.1%, P = 0.001) and MR (15.1% vs. 6.2%, P<0.001) were higher in the LMWH group while CPR (53.8% vs. 46.8%, P = 0.133), LBR (37.8% vs. 40.5%, P = 0.553), BPR (6.7% vs. 6.0%, P = 0.759) and EPR (0.0% vs. 0.7%, P = 1.000) were similar compared to the control group. To investigate the correlation of LMWH administration, confounding variables were adjusted by multivariable logistic regression model and three Propensity score (PS) methods. In multivariable logistic regression, there were significantly higher CPR (AOR = 1.54; 95% CI, 1.05–2.27; P = 0.027) and MR (AOR = 2.93; 95% CI, 1.73–4.97; P < 0.001) among patients with LMWH, without an increase in LBR (AOR = 1.03; 95% CI, 0.70–1.53; P = 0.877), MPR (AOR = 1.29; 95% CI, 0.59–2.81; P = 0.529), BPR (OR = 1.17, 95% CI, 0.56–2.45; P = 0.674), which were consistent in PS Adjustment, and Inverse Probability of Treatment Weighting using propensity score (IPTW), but not in the Propensity score matching (PSM) (1:1) analysis. Subgroup analyses showed that CPR and MR were increased in the LMWH group in the patients with age ≤ 35 years, body mass index (BMI) ≤ 24 and without recurrent pregnancy loss (RPL).
Conclusions
Low molecular weight heparin may improve clinical pregnancy but not live birth in non-thrombophilic women undergoing ART.