Animal studies of oral administration during organogenesis at up to 110 times the maximum recommended human daily oral dose did not cause any averse developmental effects. Human data from prospective and retrospective cohort studies have not identified an increase in major birth defects when this drug was used during pregnancy; limitations of the studies include small sample size, retrospective data collection, and inconsistent comparator groups. There are no controlled data in human pregnancy. The background birth defect and miscarriage risk for the indicated population is not known. In the US general population, the estimated major birth defect risk is 2 to 4% and the miscarriage risk is 15 to 20%.

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.

The manufacturer makes no recommendation regarding use during pregnancy.

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

Comments:
-Available data from decades of studies have not established a drug-associated increase in major birth defects when used during pregnancy.
-Animal studies at up to 110 times the maximum recommended human daily oral dose administered during organogenesis did not show adverse developmental effects.
-Poorly or moderately controlled asthma increases maternal risk and the risk of adverse perinatal outcomes (e.g. preeclampsia, prematurity, low birth weight, small for gestational age).

See references

The manufacturer makes no recommendation regarding use during lactation.

Excreted into human milk: Yes

Comments:
-A published study reports presence of this drug in human milk.
-Available data do not suggest significant risk of adverse events in the infant from exposure through breast milk or direct exposure.
-There is no information regarding this drug on the effects on milk production.
-Consider the developmental and health benefits of breastfeeding along with the mother's clinical need for this medication as well as any potential adverse effects from this drug or the underlying maternal condition.

See references