Animal studies have failed to reveal evidence of teratogenicity and other adverse effects on reproduction in female animal models given erythromycin base at doses up to 0.25% of the diet before and during mating, during gestation, and through lactation. There are no controlled data in human pregnancy.

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 B: Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women.

This drug should be used during pregnancy only if clearly needed.

AU TGA pregnancy category: A
US FDA pregnancy category: B

See references

Caution is recommended.

Excreted into human milk: Yes (oral and parenteral formulations); Unknown (topical formulations)
Excreted into animal milk: Data not available (topical formulations)

Comments:
-The American Academy of Pediatrics (AAP) considers this drug compatible with breastfeeding.
-Some experts state that ointments should not be applied to the breast prior to breastfeeding; if necessary, water-miscible cream or gel products may be used, but the products should not be applied to the nipple area.

Risk to the nursing infant is considered low, as only a negligible amount is absorbed after topical application.

See references