Antineoplastic
PREGNANCY RECOMMENDATION: Contraindicated—1st Trimester
BREASTFEEDING RECOMMENDATION: Contraindicated
PREGNANCY SUMMARY
No reports describing embryo–fetal harm caused by thiotepa have been located. However, the drug is a polyfunctional cytotoxic agent that is related chemically and pharmacologically to nitrogen mustard (mechlorethamine), an alkylating antineoplastic. Moreover, the animal reproduction data suggest risk.
FETAL RISK SUMMARY
Thiotepa impairs fertility and is carcinogenic, mutagenic, and teratogenic in animals (1). Reproduction studies in mice and rats at intraperitoneal doses one-eighth and one times, respectively, the maximum recommended human dose based on BSA (MRHD) revealed teratogenicity in both species. Embryolethality was noted in rabbits at a dose twice the MRHD (1).
It is not known if thiotepa crosses the human placenta. The molecular weight (about 189) is low enough that passage to the embryo–fetus should be expected.
Thiotepa has been used during the 2nd and 3rd trimesters in one patient without apparent fetal harm (2). Long-term studies of growth and mental development in offspring exposed to antineoplastic agents during the 2nd trimester, the period of neuroblast multiplication, have not been conducted (3).
Occupational exposure of the mother to antineoplastic agents during pregnancy may present a risk to the fetus. A position statement from the National Study Commission on Cytotoxic Exposure and a research article involving some antineoplastic agents are presented in the monograph for cyclophosphamide (see Cyclophosphamide).
BREASTFEEDING SUMMARY
No reports describing the use of thiotepa during lactation have been located. The molecular weight (about 189) is low enough that excretion into breast milk should be expected. Because of the potential for severe toxicity, including tumors, in a nursing infant, women receiving thiotepa should not breastfeed.
References
1.Product information. Thioplex. Immunex, 2000.
2.Gililland J, Weinstein L. The effects of cancer chemotherapeutic agents on the developing fetus. Obstet Gynecol Surv 1983;38:6–13.
3.Dobbing J. Pregnancy and leukaemia. Lancet 1977;1:1155.