Animal studies have revealed evidence of embryotoxicity and teratogenicity at doses less than the expected maximum recommended human daily dose. This drug can cause fetal malformations (partially ossified cranial bones, absence of eye sockets, hydrocephaly, bipartite sternebrae, missing lumbar vertebrae). Embryotoxicity was characterized by decreased fetal viability, reduced live litter sizes, and developmental delays. There are no controlled data in human pregnancy.

Azoospermia or oligospermia, sometimes reversible, have been observed in men. Male patients should be informed about the possibility of sperm conservation before the start of the therapy.

AU TGA pregnancy category D: Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects. Accompanying texts should be consulted for further details.

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.

Use should be avoided.

AU TGA pregnancy category: D
US FDA pregnancy category: Not assigned.

Risk Summary: There are no studies with use of this drug in pregnant women. This drug can cause fetal harm based on animal studies and its mechanism of action; this drug affects DNA synthesis, and therefore it's a potentially mutagenic agent.

Comments:
-Verify the pregnancy status of females of reproductive potential prior to initiating therapy.
-If this drug is used during pregnancy or if a patient becomes pregnant while taking this drug, the patient should be apprised of the potential harm to the fetus.
-Females of reproductive potential should use contraception during therapy and for at least 6 months after discontinuing therapy.
-Males of reproductive potential should use contraception during therapy and for at least 1 year after discontinuing therapy.

See references

Not Recommended

Excreted into human milk: Yes

Comments:
-Because of the potential for serious adverse reactions in a breastfed infant from hydroxyurea (including carcinogenicity) the manufacturers recommend breastfeeding being avoided during treatment.

Most experts consider breastfeeding contraindicated during maternal antineoplastic drug therapy. With doses used for sickle cell disease, breastfeeding appears to be acceptable. Mothers should be advised to avoid breastfeeding for 3 hours after dosing as this decreases the infant dose by about half. Chemotherapy may adversely affect the normal microbiome and chemical makeup of breastmilk.

See references