letrozole · Medicine question

Why is Femara (letrozole) contraindicated during pregnancy?

iatroX medicinesPublished 8 November 2026

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Femara (letrozole) is contraindicated during pregnancy because it may cause congenital malformations, with isolated birth defects reported in humans and reproductive toxicity shown in animal studies.

Sources for this answer

Femara 2.5 mg TabletsNovartis Pharmaceuticals UK Ltd · emc · SmPC §4.6 Fertility, pregnancy and lactation · Version 35Document updated 2 September 2025

Sources checked 8 November 2026

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