According to some authorities: As a precaution, this drug should not be used during pregnancy unless the benefit outweighs the risk to the fetus.

US FDA pregnancy category: Not assigned.

Risk summary: Insufficient data available on use of this drug in pregnant women to inform a drug-related risk.

Animal studies have revealed evidence of teratogenicity and other fetal harm. In pregnant rats, non-dose-related imbalances in visceral and skeletal findings (including 13th reduced ribs, additional liver lobes, testes medially displaced and/or not descended) were observed with oral gavage doses of this drug from gestation through organogenesis at human systemic exposures after a maximum oral dose of 4 g/day based on body surface (BSA) comparisons. In pregnant rabbits administered oral gavage doses of this drug from gestation through organogenesis, a decrease in body weight and food intake was seen at 1 g/kg/day (5 times the human exposure at the maximum dose of 4 g/day, based on BSA comparisons), and slight increases in resorbed and dead fetuses were noted at this dose (not significantly different from the control group); there were no treatment-related malformations or skeletal anomalies. There are no controlled data in human pregnancy.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

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According to some authorities: A decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother and the benefit of breastfeeding for the child.

Excreted into human milk: (parent drug: Unknown; active metabolite eicosapentaenoic acid [EPA]: Yes)
Excreted into animal milk: Yes

Comments:
-Developmental and health benefits of breastfeeding should be considered as well as the mother's clinical need for this drug.
-The effects in the nursing infant are unknown; potential side effects in the breastfed child due to this drug or the mother's underlying condition should be considered. A risk to the nursing child cannot be excluded.
-Published studies have detected omega-3 fatty acids (including EPA) in human milk; supplementation with oral omega-3 fatty acids in lactating women has resulted in higher levels of omega-3 fatty acids in human milk.
-Published studies have shown that EPA is excreted in human milk at levels correlating to maternal diet.

See references