Use is not recommended unless the benefit outweighs the risk to the fetus

AU TGA pregnancy category: A
US FDA pregnancy category: Not assigned

Risk Summary: Available data in human pregnancy are insufficient to inform a drug-associated risk for major birth defects and miscarriage; prolonged use of opioids during pregnancy can result in physical dependence in the neonate; animal reproduction studies have shown potential fetal harm.

Comments:
-Women should be advised of the risk of neonatal abstinence syndrome and ensure that appropriate treatment will be available.

This drug has been shown to be embryolethal and fetotoxic in the hamster, rat, and mouse at doses of approximately 2 to 4 times the maximum recommended human dose. Maternally toxic doses (7 times the maximum recommended human dose) were associated with evidence of resorptions and incomplete ossification, including meningoencephalocele and cranioschisis. In the rabbit model, embryotoxicity and foetotoxicity were not observed. Opioid analgesics cross the placenta. The use of this drug during labor may cause respiratory depression in the newborn infant. Prolonged use of opioids during pregnancy can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth. The onset, duration, and severity of the condition will vary based on use (duration of use, timing, and amount of last maternal use) and rate of elimination in the newborn. There are no controlled data in human pregnancy.

Chronic use of opioids may cause reduced fertility; it is unknown whether these effects are reversible.

AU TGA pregnancy category A: Drugs which have been taken by a large number of pregnant women and women of childbearing age without any proven increase in the frequency of malformations or other direct or indirect harmful effects on the fetus having been observed.

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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Not recommended

Excreted into human milk: Yes

Comments:
-Breastfeeding is not recommended (US) and contraindicated by some authorities (AU and UK) due to the risks of serious adverse reactions in breastfed infants such as excess sleepiness, difficulty breastfeeding, and serious breathing problems that may result in death; pharmacogenetics appears to play a role.
-If used, maternal intake should be limited to 2 to 4 days at a low dosage with close infant monitoring; if baby show signs of increased sleepiness, difficulty breastfeeding, breathing difficulties, or limpness, seek immediate attention.

Codeine is present in breast milk and for women with normal codeine metabolism (normal CYP450 2D6 activity) the amount of codeine secreted is low and dose-dependent; however, in women who are ultra-rapid metabolizers of codeine (those with a specific CYP450 2D6 genotype) higher-than-expected serum levels of morphine, codeine's active metabolite, may be present in their breast milk which may lead to dangerously high serum morphine levels in their breastfed infants. In most cases, a person's specific CYP450 2D6 genotype is unknown. Several small series and 1 small retrospective study suggest that codeine may be causative in episodes of apnea, bradycardia, and cyanosis in the first week of life. A death of a breastfeed infant due to respiratory depression has been reported; the mother was found to be a CYP450 2D6 ultrarapid metabolizer.

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