Heparin
1. Pregnancy Evidence & Regulatory Labeling
FDA Pregnancy and Lactation Labeling Rule (PLLR 8.1) & EMA SmPC Section 4.6
Clinical Risk Summary
There are no available data on Heparin Sodium Injection use in pregnant women to inform a drug-associated risk of major birth defects and miscarriage. In published reports, heparin exposure during pregnancy did not show evidence of an increased risk of adverse maternal or fetal outcomes in humans. No teratogenicity, but early embryo-fetal death was observed in animal reproduction studies with administration of heparin sodium to pregnant rats and rabbits during organogenesis at doses approximately 10 times the maximum recommended human dose (MRHD) of 45,000 units/day [see Data ] . Consider the benefits and risks of Heparin Sodium Injection for the mother and possible risks to the fetus when prescribing Heparin Sodium Injection to a pregnant woman. If available, preservative-free Heparin Sodium Injection is recommended when heparin therapy is needed during pregnancy. There are no known adverse outcomes associated with fetal exposure to the preservative benzyl alcohol through maternal drug administration; however, the preservative benzyl alcohol can cause serious adverse events and death when administered intravenously to neonates and infants [see Warnings and Precautions ( 5.4 )] . The background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Data Human Data The maternal and fetal outcomes associated with uses of heparin via various dosing methods and administration routes during pregnancy have been investigated in numerous studies. These studies generally reported normal deliveries with no maternal or fetal bleeding and no other complications. Animal Data In a published study conducted in rats and rabbits, pregnant animals received heparin intravenously during organogenesis at a dose of 10,000 units/kg/day, approximately 10 times the maximum human daily dose based on body weight. The number of early resorptions increased in both species. There was no evidence of teratogenic effects.
Human Pregnancy Experience & Clinical Studies
The maternal and fetal outcomes associated with uses of heparin via various dosing methods and administration routes during pregnancy have been investigated in numerous studies. These studies generally reported normal deliveries with no maternal or fetal bleeding and no other complications. Animal Data In a published study conducted in rats and rabbits, pregnant animals received heparin intravenously during organogenesis at a dose of 10,000 units/kg/day, approximately 10 times the maximum human daily dose based on body weight. The number of early resorptions increased in both species. There was no evidence of teratogenic effects.
Animal Reproductive & Developmental Toxicity Data
In a published study conducted in rats and rabbits, pregnant animals received heparin intravenously during organogenesis at a dose of 10,000 units/kg/day, approximately 10 times the maximum human daily dose based on body weight. The number of early resorptions increased in both species. There was no evidence of teratogenic effects.
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
Evaluated in human/animal pharmacokinetic models.
3. Females & Males of Reproductive Potential
FDA Labeling Section 8.3 — Pregnancy Testing, Contraception & Infertility
Standard pre-treatment clinical assessment as indicated.
Review contraception duration based on drug elimination half-life.
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 | 2025-09-26 | Official Record |
|
European Medicines Agency (EMA)
EMA Summary of Product Characteristics (SmPC 4.6)
|
European Union | regulatory_label | Recent | Official Record |