QUESTO HUB
QUESTO HEALTHCARE ECOSYSTEM Clinical Pharmacology & Maternal-Fetal Drug Safety Center
Document ID: Q-PREG-A9B5CCCB
Date Issued: October 07, 2026
Regulatory Base: US FDA (PLLR 8.1/8.2) & NIH LactMed®
Verified Portal: questocomm.com/pregnancy-safety/enoxaparin
OFFICIAL CLINICAL MONOGRAPH

ENOXAPARIN

Evidence-Based Medication Safety Profile for Maternal & Lactation Practice
Pregnancy & Lactation Center
Clinical Monograph Prescription / OTC (Enoxaparin Sodium)
Regulatory Boxed Warning

Enoxaparin

UNII Code 8NZ41MIK1O
RxNorm CUI 854228
Prescribing & Clinical Reference: Compiled from official regulatory labeling (US FDA PLLR, NIH LactMed®, EMA). Clinical decisions during pregnancy and lactation require individualized patient assessment and physician consultation.

1. Pregnancy Evidence & Regulatory Labeling

FDA Pregnancy and Lactation Labeling Rule (PLLR 8.1) & EMA SmPC Section 4.6

Clinical Risk Summary

Placental transfer of enoxaparin was observed in the animal studies. Human data from a retrospective cohort study, which included 693 live births, suggest that enoxaparin sodium does not increase the risk of major developmental abnormalities [see Data]. Based on animal data, enoxaparin is not predicted to increase the risk of major developmental abnormalities [see Data]. Adverse outcomes in pregnancy occur regardless of the health of the mother or the use of medications. The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Pregnancy alone confers an increased risk for thromboembolism that is even higher for women with thromboembolic disease and certain high risk pregnancy conditions. While not adequately studied, pregnant women with mechanical prosthetic heart valves may be at even higher risk for thrombosis [see Warnings and Precautions (5.7) and Use in Specific Populations (8.6) ] . Pregnant women with thromboembolic disease, including those with mechanical prosthetic heart valves and those with inherited or acquired thrombophilias, have an increased risk of other maternal complications and fetal loss regardless of the type of anticoagulant used. All patients receiving anticoagulants, including pregnant women, are at risk for bleeding. Pregnant women receiving enoxaparin should be carefully monitored for evidence of bleeding or excessive anticoagulation. Consideration for use of a shorter acting anticoagulant should be specifically addressed as delivery approaches [see Boxed Warning ] . Hemorrhage can occur at any site and may lead to death of mother and/or fetus. Pregnant women should be apprised of the potential hazard to the fetus and the mother if enoxaparin is administered during pregnancy. It is not known if monitoring of anti-Factor Xa activity and dose adjustment (by weight or anti-Factor Xa activity) of enoxaparin sodium affect the safety and the efficacy of the drug during pregnancy. Data Human Data There are no adequate and well-controlled studies in pregnant women. A retrospective study reviewed the records of 604 women who used enoxaparin during pregnancy. A total of 624 pregnancies resulted in 693 live births. There were 72 hemorrhagic events (11 serious) in 63 women. There were 14 cases of neonatal hemorrhage. Major congenital anomalies in live births occurred at rates (2.5%) similar to background rates. There have been postmarketing reports of fetal death when pregnant women received enoxaparin sodium. Causality for these cases has not been determined. Insufficient data, the underlying disease, and the possibility of inadequate anticoagulation complicate the evaluation of these cases. A clinical study using enoxaparin in pregnant women with mechanical prosthetic heart valves has been conducted [see Warnings and Precautions (5.7) ] . Animal Data Teratology studies have been conducted in pregnant rats and rabbits at subcutaneous doses of enoxaparin up to 15 times the recommended human dose (by comparison with 2 mg/kg as the maximum recommended daily dose). There was no evidence of teratogenic effects or fetotoxicity due to enoxaparin. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Human Pregnancy Experience & Clinical Studies

from a retrospective cohort study, which included 693 live births, suggest that enoxaparin sodium does not increase the risk of major developmental abnormalities [see Data]. Based on animal data, enoxaparin is not predicted to increase the risk of major developmental abnormalities [see Data]. Adverse outcomes in pregnancy occur regardless of the health of the mother or the use of medications. The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Pregnancy alone confers an increased risk for thromboembolism that is even higher for women with thromboembolic disease and certain high risk pregnancy conditions. While not adequately studied, pregnant women with mechanical prosthetic heart valves may be at even higher risk for thrombosis [see Warnings and Precautions (5.7) and Use in Specific Populations (8.6) ] . Pregnant women with thromboembolic disease, including those with mechanical prosthetic heart valves and those with inherited or acquired thrombophilias, have an increased risk of other maternal complications and fetal loss regardless of the type of anticoagulant used. All patients receiving anticoagulants, including pregnant women, are at risk for bleeding. Pregnant women receiving enoxaparin should be carefully monitored for evidence of bleeding or excessive anticoagulation. Consideration for use of a shorter acting anticoagulant should be specifically addressed as delivery approaches [see Boxed Warning ] . Hemorrhage can occur at any site and may lead to death of mother and/or fetus. Pregnant women should be apprised of the potential hazard to the fetus and the mother if enoxaparin is administered during pregnancy. It is not known if monitoring of anti-Factor Xa activity and dose adjustment (by weight or anti-Factor Xa activity) of enoxaparin sodium affect the safety and the efficacy of the drug during pregnancy. Data Human Data There are no adequate and well-controlled studies in pregnant women. A retrospective study reviewed the records of 604 women who used enoxaparin during pregnancy. A total of 624 pregnancies resulted in 693 live births. There were 72 hemorrhagic events (11 serious) in 63 women. There were 14 cases of neonatal hemorrhage. Major congenital anomalies in live births occurred at rates (2.5%) similar to background rates. There have been postmarketing reports of fetal death when pregnant women received enoxaparin sodium. Causality for these cases has not been determined. Insufficient data, the underlying disease, and the possibility of inadequate anticoagulation complicate the evaluation of these cases. A clinical study using enoxaparin in pregnant women with mechanical prosthetic heart valves has been conducted [see Warnings and Precautions (5.7) ] . Animal Data Teratology studies have been conducted in pregnant rats and rabbits at subcutaneous doses of enoxaparin up to 15 times the recommended human dose (by comparison with 2 mg/kg as the maximum recommended daily dose). There was no evidence of teratogenic effects or fetotoxicity due to enoxaparin. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Animal Reproductive & Developmental Toxicity Data

Teratology studies have been conducted in pregnant rats and rabbits at subcutaneous doses of enoxaparin up to 15 times the recommended human dose (by comparison with 2 mg/kg as the maximum recommended daily dose). There was no evidence of teratogenic effects or fetotoxicity due to enoxaparin. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Clinical Considerations for Prescribers

Pregnancy alone confers an increased risk for thromboembolism that is even higher for women with thromboembolic disease and certain high risk pregnancy conditions. While not adequately studied, pregnant women with mechanical prosthetic heart valves may be at even higher risk for thrombosis [see Warnings and Precautions (5.7) and Use in Specific Populations (8.6) ] . Pregnant women with thromboembolic disease, including those with mechanical prosthetic heart valves and those with inherited or acquired thrombophilias, have an increased risk of other maternal complications and fetal loss regardless of the type of anticoagulant used. All patients receiving anticoagulants, including pregnant women, are at risk for bleeding. Pregnant women receiving enoxaparin should be carefully monitored for evidence of bleeding or excessive anticoagulation. Consideration for use of a shorter acting anticoagulant should be specifically addressed as delivery approaches [see Boxed Warning ] . Hemorrhage can occur at any site and may lead to death of mother and/or fetus. Pregnant women should be apprised of the potential hazard to the fetus and the mother if enoxaparin is administered during pregnancy. It is not known if monitoring of anti-Factor Xa activity and dose adjustment (by weight or anti-Factor Xa activity) of enoxaparin sodium affect the safety and the efficacy of the drug during pregnancy. Data Human Data There are no adequate and well-controlled studies in pregnant women. A retrospective study reviewed the records of 604 women who used enoxaparin during pregnancy. A total of 624 pregnancies resulted in 693 live births. There were 72 hemorrhagic events (11 serious) in 63 women. There were 14 cases of neonatal hemorrhage. Major congenital anomalies in live births occurred at rates (2.5%) similar to background rates. There have been postmarketing reports of fetal death when pregnant women received enoxaparin sodium. Causality for these cases has not been determined. Insufficient data, the underlying disease, and the possibility of inadequate anticoagulation complicate the evaluation of these cases. A clinical study using enoxaparin in pregnant women with mechanical prosthetic heart valves has been conducted [see Warnings and Precautions (5.7) ] . Animal Data Teratology studies have been conducted in pregnant rats and rabbits at subcutaneous doses of enoxaparin up to 15 times the recommended human dose (by comparison with 2 mg/kg as the maximum recommended daily dose). There was no evidence of teratogenic effects or fetotoxicity due to enoxaparin. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Regulatory Warnings & Contraindications

FDA Boxed Warning: This medication carries an official Boxed Warning regarding embryo-fetal toxicity or pregnancy-related adverse outcomes.

4 CONTRAINDICATIONS Enoxaparin sodium injection is contraindicated in patients with: • Active major bleeding • History of immune-mediated heparin-induced thrombocytopenia (HIT) within the past 100 days or in the presence of circulating antibodies [see Warnings and Precautions (5.4) ] • Known hypersensitivity to enoxaparin sodium (e.g., pruritus, urticaria, anaphylactic/ anaphylactoid reactions) [see Adverse Reactions (6.2) ] • Known hypersensitivity to heparin or pork products Active major bleeding ( 4 ) History of heparin-induced thrombocytopenia (HIT) within the past 100 days or in the presence of circulating antibodies ( 4 ) Hypersensitivity to enoxaparin sodium ( 4 ) Hypersensitivity to heparin or pork products ( 4 )

2. Lactation & Breastfeeding Safety

NIH / NLM LactMed® Database & FDA Labeling Section 8.2

Summary of Use during Lactation

Review infant exposure and nursing considerations before administration.

Drug Levels in Breast Milk & Relative Infant Dose

Relative Infant Dose (RID) Indexed in Clinical Studies RID <10% is generally considered low by clinical guidelines.
Milk Concentration & Transport

Evaluated in human/animal pharmacokinetic models.

3. Females & Males of Reproductive Potential

FDA Labeling Section 8.3 — Pregnancy Testing, Contraception & Infertility

Pregnancy Testing

Standard pre-treatment clinical assessment as indicated.

Contraception & Washout

Review contraception duration based on drug elimination half-life.

Infertility Considerations

No significant drug-induced impairment reported in standard models.

4. Regulatory Source Provenance & Comparison

Direct attribution to official regulatory documents without synthesized consensus

Regulatory Organization Jurisdiction Document / Framework Effective Date Official Source Link
U.S. Food and Drug Administration (FDA)
FDA Prescribing Information (PLLR)
United States regulatory_label 2024-06-21 Official Record
European Medicines Agency (EMA)
EMA Summary of Product Characteristics (SmPC 4.6)
European Union regulatory_label Recent Official Record
U.S. Food and Drug Administration (FDA) FDA Prescribing Information (PLLR)
United States
Framework: regulatory_label
Effective Date: 2024-06-21
View Official Regulatory Record
European Medicines Agency (EMA) EMA Summary of Product Characteristics (SmPC 4.6)
European Union
Framework: regulatory_label
Effective Date: Recent
View Official Regulatory Record

System Notice

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