Amoxicillin-clavulanate has been assigned to pregnancy category B by the FDA. Animal studies failed to reveal any evidence of teratogenicity. There are no controlled data in human pregnancies. The results of a study suggest an increased risk of necrotizing enterocolitis in neonates if amoxicillin-clavulanate is given prophylactically to women with premature rupture of membranes. Amoxicillin-clavulanate should only be given during pregnancy when need has been clearly established.

In the Collaborative Perinatal Project involving 50,282 mother-child pairs, there were 3,546 mother-child pairs exposed to penicillin derivatives in the first trimester. As a group, there was no significant increase in the risk of malformations. In the Michigan Medicaid Birth Defects Study involving 229,101 pregnancies from 1985 to 1992, there were 8,538 first trimester exposures to amoxicillin. Overall, 317 cases of birth defects were observed (363 expected). There was no evidence of an association between first trimester use of amoxicillin and major groups of malformations. In the Michigan Medicaid Birth Defects Study, there were 556 first trimester exposures to clavulanate. Overall, 24 cases of birth defects were observed (24 expected). Two cases of spina bifida occurred compared with only 0.3 cases expected, representing a statistically significant increase in the incidence of this anomaly.

In one study, six women were administered a single 1000 mg dose of amoxicillin on the third postpartum day. Amoxicillin milk concentrations ranged from 0.10 to 0.81 mcg/mL, with a peak concentration measured at 5 hours post-dose. The milk to maternal serum concentration ratio ranged from 0.013 to 0.043.

Amoxicillin is excreted into human milk in small amounts and is considered compatible with breast-feeding by the American Academy of Pediatrics. Clavulanate has not been detected in human milk. Adverse effects in the nursing infant are unlikely. The manufacturer recommends caution when amoxicillin-clavulanate is administered to a nursing woman.