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

US FDA pregnancy category: B

Animal studies have failed to reveal evidence of fetal harm. There are no controlled data in human pregnancy.

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.

See references

Candidiasis and diarrhea have been reported in an infant exposed to ampicillin via breast milk; causality unknown.

Milk levels were 0.3 to 0.9 mg/L in 3 mothers who received ampicillin 2 g IM daily and 0.4 to 0.9 mg/L in 3 mothers who received 4 g IM daily. Peak milk levels were observed 3 hours postdose. It was estimated that the breastfed infant received 0.08 to 0.2 mg ampicillin daily with such doses.

Milk ampicillin levels averaged 0.11, 0.21, 0.17, 0.27, and 0.26 mg/L at 30 minutes, 1 hour, 2 hours, 4 hours, and 6 hours after the dose, respectively, in 15 women receiving ampicillin 500 mg IM 4 times a day.

Two hours after a single dose of ampicillin 2 g IV, milk levels averaged 1.1 mg/L.

Milk was collected at random times after doses of sulbactam 0.5 or 1 g infused IV over 20 minutes. Milk levels averaged 0.52 mg/L during the first 8 hours postdose and the highest level was 2.8 mg/L; milk levels varied slightly over that period and there was little difference between the 2 doses. Levels obtained 10.5 to 20.5 hours postdose were 0.12 to 1.2 mg/L.

In a study, postpartum women with endometritis received ampicillin 1 g plus sulbactam 0.5 g or ampicillin 2 g plus sulbactam 1 g infused IV over 20 minutes. Ampicillin milk levels averaged 1.7 mg/L and the highest level was 3 mg/L. Sulbactam milk levels averaged 0.58 mg/L and the highest level was 2.8 mg/L.

Five nursing mothers reported taking oral ampicillin (dose not provided) in a prospective follow-up study. One mother reported diarrhea in her infant. Neither rash nor candidiasis was observed in exposed infants.

During a small and controlled prospective study, mothers monitored their infants for signs of side effects (furring of the tongue, feeding difficulties, changes in stool frequency and consistency, diaper rash, skin rash), weight change, and jaundice. These parameters were not statistically different when infants of control mothers and of mothers taking oral ampicillin were compared.

Use is considered acceptable; caution is recommended.

Excreted into human milk: Yes (both components in small amounts)

Comments:
-Low levels in milk are not expected to cause harmful effects in the nursing infant.
-Ampicillin is considered compatible with breastfeeding by the WHO.
-Sulbactam is considered compatible with breastfeeding by the American Academy of Pediatrics.

See references