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Cyclophosphamide Pregnancy and Breastfeeding Warnings

Medically reviewed by Last updated on Nov 28, 2022.

Cyclophosphamide is also known as: Cytoxan, Cytoxan Lyophilized, Neosar

Cyclophosphamide Pregnancy Warnings

Use is contraindicated.

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

Risk Summary: Based on its mechanism of action and effects in pregnant patients or animals, this drug can cause fetal harm when administered to a pregnant woman. Exposure during pregnancy may cause fetal malformations, miscarriage, fetal growth retardation, and toxic effects in the newborn. This drug is teratogenic and embryofetal toxic in mice, rats, rabbits, and monkeys.

-This drug can harm a developing fetus.
-Adequate methods of contraception should be encouraged.
-Verify negative pregnancy status in females of reproductive potential prior to initiating therapy.
-If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential harm to the fetus.
-Advise female patients of reproductive potential to avoid becoming pregnant and to use effective contraception during treatment and for up to 1 year after completion of therapy.
-Advise male patients with female partners of reproductive potential to use effective contraception during therapy and for 4 months after.
-Amenorrhea, transient or permanent, associated with decreased estrogen and increased gonadotropin secretion has been reported. Patients generally resume regular menses within a few months after cessation. The risk of premature menopause increases with age.
-Oligomenorrhea has been reported.
-Males may develop oligospermia or azoospermia which are normally associated with increased gonadotropin but normal testosterone secretion.

Malformations of the skeleton, palate, limbs, and eyes as well as miscarriage have been reported after exposure to this drug during the first trimester. Fetal growth retardation and toxic effects manifesting in the newborn, including leukopenia, anemia, pancytopenia, severe bone marrow hypoplasia, and gastroenteritis have been reported after exposure to this drug. Animal data suggest an increased risk of failed pregnancy and malformations that may persist after discontinuation of therapy if oocytes/follicles exist that were exposed during any of their maturation phases. The exact duration of follicular development in humans is not known but may be longer than 12 months.

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.

See references

Cyclophosphamide Breastfeeding Warnings

The American Academy of Pediatrics considers breastfeeding to be contraindicated during maternal antineoplastic drug therapy (especially alkylating agents). Neutropenia, thrombocytopenia, and immune suppression have been observed in infants whose mothers were receiving this drug during lactation. The drug also has an unacceptable risk of carcinogenesis.

Use is contraindicated.

Excreted into human milk: Yes

-This drug can harm a nursing infant.
-Chemotherapy may adversely affect the normal microbiome and chemical makeup of breastmilk.
-Women who receive chemotherapy during pregnancy are more likely to have difficulty nursing their infant.

See references

References for pregnancy information

  1. "Product Information. Cyclophosphamide (cyclophosphamide)." Amneal Biosciences LLC (2018):

References for breastfeeding information

  1. United States National Library of Medicine "Toxnet. Toxicology Data Network." (2013):
  2. "Product Information. Cyclophosphamide (cyclophosphamide)." Amneal Biosciences LLC (2018):

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.