Animal studies have revealed evidence of embryofetal toxicity and embryolethality. After oral doses (up to 250 mg/kg/day) to pregnant rats throughout organogenesis, embryofetal toxicity (decreased fetal body weight, delayed ossification) and maternal toxicity (reduced body weight) were seen at the highest dose tested; plasma exposures (AUC) for monomethyl fumarate (MMF; active metabolite) at the no-effect dose were about 3 times that in humans at the recommended human dose (RHD) of 480 mg/day. After oral doses (up to 150 mg/kg/day) to pregnant rabbits throughout organogenesis, embryolethality and decreased maternal body weight were seen at the highest dose tested; plasma AUC for MMF at the no-effect dose was about 5 times that in humans at the RHD. There are no controlled data in human pregnancy.

To monitor the outcomes of pregnant women exposed to this drug, a pregnancy registry has been established. Patients should be encouraged to enroll by calling 1-866-810-1462 or visiting www.tecfiderapregnancyregistry.com.

AU TGA pregnancy category B1: Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals have not shown evidence of an increased occurrence of fetal damage.

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.

CAPSULES: This product is not recommended during pregnancy and in patients of childbearing potential not using appropriate contraception; this product should be used during pregnancy only if clearly needed and the benefit outweighs the risk to the fetus.

TABLETS: Use is contraindicated. This product is not recommended in patients of childbearing potential not using appropriate contraception.

AU TGA pregnancy category: B1
US FDA pregnancy category: Not assigned.

Risk summary: Based on animal data, this drug may cause fetal harm; no adequate data available on the developmental risk associated with use of this drug in pregnant women.

Comments:
-A pregnancy exposure registry is available.
-Patients should be advised to inform their health care provider if they are pregnant or plan to become pregnant during therapy.
-TABLETS: Additional contraceptive methods could be needed if stomach and intestinal problems occur that could reduce the efficacy of oral contraceptives.

See references

This drug is not found in plasma as it is rapidly converted to the active metabolite, monomethyl fumarate, which has a half-life of about 1 hour.

This drug (240 mg orally twice a day) was started in 2 nursing mothers with relapsing-remitting multiple sclerosis after breastfeeding was discontinued; they continued pumping milk and on day 8 of therapy, they each provided milk samples at 1, 2, 4, 8, and 12 hours after dosing. Peak monomethyl fumarate milk levels were 3.7 mcg/L in 1 mother and 11.2 mcg/L in the other and occurred at about 2 hours after dosing; milk levels averaged 2.7 and 7.5 mcg/L, respectively. These values indicate that the infants would receive about 0.8 and 1.13 mcg/kg/day, respectively, or weight-adjusted relative infant dosages of 0.007% and 0.019% of the maternal dosage.

CAPSULES:
-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.

TABLETS: Use is contraindicated.

Excreted into human milk: No (as parent drug); Yes (as active metabolite [monomethyl fumarate])

Comments:
-No information is available on the clinical use of this drug during breastfeeding.
-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 newborns/infants cannot be excluded.
-Amounts of monomethyl fumarate in breast milk appear low and would not be expected to cause any adverse effects in breastfed infants.
---Breastfed infants should be monitored for adequate weight gain and developmental milestones, especially younger, exclusively breastfed infants.
---Some experts also recommend monitoring breastfed infants for flushing, vomiting, and diarrhea.

See references