Mavenclad (cladribine) is **not considered safe during pregnancy** due to its potential to cause serious fetal harm. It is explicitly contraindicated for use in pregnant women and in women and men of reproductive potential who do not plan to use effective contraception during treatment and for at least six months after the last dose of each treatment course. This is because Mavenclad has teratogenic effects, meaning it can cause birth defects or harm to the developing fetus if exposure occurs during pregnancy.
Before starting Mavenclad, women of childbearing potential must have a confirmed negative pregnancy test to ensure they are not pregnant. This test is typically done before each treatment course. During treatment and for six months after the last dose, effective contraception must be used to prevent pregnancy. For women using hormonal contraceptives such as the birth control pill, additional barrier methods like condoms are recommended during treatment and for at least four weeks after the last dose in each cycle to ensure protection.
Men taking Mavenclad should also use effective contraception if their female partners are of childbearing potential, continuing this practice during treatment and for six months after the last dose to prevent potential risks to a fetus conceived during this period.
Breastfeeding is also not recommended during Mavenclad treatment and for 10 days after the last dose, as the drug may pass into breast milk and harm the infant.
The reason for these strict precautions is that Mavenclad works by reducing lymphocyte counts and altering immune function, which can interfere with normal fetal development. Its mechanism as a purine nucleoside analog can disrupt DNA synthesis and repair, which is particularly dangerous during the rapid cell division and growth phases of pregnancy.
Because of these risks, if a woman becomes pregnant during Mavenclad treatment, the medication should be discontinued immediately, and she should consult her healthcare provider for appropriate management.
In addition to pregnancy-related concerns, Mavenclad carries other significant warnings, including an increased risk of malignancies and infections, which further complicate its use in vulnerable populations such as pregnant women.
In summary, Mavenclad is **strictly contraindicated during pregnancy** due to its potential to cause fetal harm. Both women and men of reproductive potential must use effective contraception during treatment and for six months afterward. Pregnancy testing before treatment initiation and careful planning around family planning are essential parts of safe Mavenclad use. Breastfeeding should be avoided during and shortly after treatment to protect the infant from exposure.
