Use is not recommended.
-According to some authorities, this drug should be used during pregnancy only if the benefit outweighs the risk to the fetus.

US FDA pregnancy category: Not formally assigned to a pregnancy category.

Comments: Infants born to mothers who received substantial doses of corticosteroids during pregnancy should be observed carefully for signs of hypoadrenalism.

Animal studies with dexamethasone have revealed evidence of teratogenicity following topical ophthalmic application in multiples of the therapeutic dose. Animal studies with corticosteroids produced fetal resorptions, cleft palate, and abnormalities involving the head, ears, and limbs. Prolonged or repeated corticoid use has been associated with an increased risk of intrauterine growth retardation. Animal studies with neomycin sulfate and polymyxin B have not been reported. There are no controlled data in human pregnancy.

See references

It is unknown whether topically administered corticosteroids could result in sufficient systemic absorption to produce detectable levels in breast milk; however, systemically administered corticosteroids may appear in breast milk and could suppress growth, interfere with endogenous corticosteroid production, or cause untoward effects.

Caution is recommended.
-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.

Excreted into human milk: Unknown
Excreted into animal milk: Data not available

Comments:
-Absorption from the eye is limited, therefore this drug would not be expected to cause any adverse effects in the breastfed infant.
-Placing pressure over the tear duct by the corner of the eye for at least 1 minute and removing excess solution with an absorbent tissue substantially reduces the amount of drug that reaches breast milk after using eye drops.

See references