Low molecular weight heparin use during pregnancy and risk of postpartum hemorrhage: a systematic review and meta-analysis.
Research article published in The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians (2019)
Abstract
INTRODUCTION: Postpartum hemorrhage (PPH) is the leading cause of maternal mortality worldwide with a prevalence rate of approximately 6%. Although most cases of PPH have no identifiable risk factors, the incidence of PPH has been associated to the thromboprophylaxis in pregnancy with low molecular weight heparin (LMWH). Thus, the aim of the study is to evaluate the risk of PPH in cases of pregnant women exposed to LMWH. MATERIALS AND METHODS: Electronic research was performed in OVID, Scopus, ClinicalTrials.gov, MEDLINE, the PROSPERO International Prospective Register of Systematic Reviews, EMBASE, and the Cochrane Central Register of Controlled Trials through April 2016. We included randomized controlled trials, cohort and case-control studies of women who underwent thromboprophylaxis with LMWH during pregnancy compared to a control group (either placebo or no treatment). The primary outcome was the incidence of PPH. The summary measures were reported as relative risk (RR) or as mean differences (MD) with 95% confidence interval (CI). RESULTS: Eight studies including 22,162 women were analyzed. Of the 22,162 women, 1320 (6%) were administered LMWH, 20,842 (94%) women formed the nonexposed group (control group). Women treated with LMWH had a higher risk of PPH (RR 1.45, 95%CI 1.02-2.05) compared to controls; there was no difference in mean of blood loss at delivery (MD -32.90, 95%CI 68.72-2.93) and in risk of blood transfusion at delivery (RR 1.24, 95%CI 0.62-2.51), respectively. CONCLUSIONS: Women who receive LMWH during pregnancy have a significantly higher risk of developing PPH. Women who receive LMWH during pregnancy have neither significantly higher mean blood loss at delivery nor higher risk of blood transfusion.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
Low molecular weight heparin use during pregnancy and risk of postpartum hemorrhage: a systematic review and meta-analysis.
Why This Matters for Hirudotherapy
This systematic review and meta-analysis of eight studies and 22,162 women found that low-molecular-weight heparin thromboprophylaxis during pregnancy was associated with a significantly higher risk of postpartum hemorrhage (RR 1.45, 95% CI 1.02-2.05), though with no significant difference in mean blood loss or transfusion risk. Its relevance to hirudotherapy is indirect, illustrating the bleeding trade-offs inherent to systemic anticoagulants like heparin, in contrast to the localized, self-limiting bleeding of leech application. The caveat is substantial: this meta-analysis concerns systemic LMWH in obstetric patients and has no connection to medicinal leeches or the leech secretome, so it offers only general anticoagulation context and no support for leech therapy.
Citation
Low molecular weight heparin use during pregnancy and risk of postpartum hemorrhage: a systematic review and meta-analysis.
Sirico et al. · The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians, 2019
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