What is the current first-line fertility treatment for PCOS according to international guidelines?

[Verified against the International Guideline for PMOS (formerly PCOS)] Letrozole should be the first-line pharmacological treatment for ovulation induction in infertile anovulatory women with PMOS/PCOS who have no other infertility factors (evidence-based recommendation, 5.3.1). Two practice points attach to that: Letrozole remains off-label in many countries. Where its use is not permitted, clinicians could use other ovulation induction agents (5.3.2). This matters for Indian practice — confirm your local regulatory position. Letrozole should not be given where there is any possibility of a pre-existing pregnancy, although there is no evidence of increased teratogenicity compared with other ovulation induction agents (5.3.3). That second clause is worth knowing, because the teratogenicity concern is frequently overstated in discussion. The comparison is explicit: letrozole should be used rather than clomiphene citrate in women with PMOS/PCOS with anovulatory infertility and no other infertility factors, to improve ovulation, clinical pregnancy and live birth rates (evidence-based recommendation, 5.4.5.2). Note the qualifier throughout — "with no other infertility factors". These recommendations assume a completed fertility assessment of both partners. Screening for other factors before starting ovulation induction is a prerequisite, not an optional step. Terminology: PCOS was renamed polyendocrine metabolic ovarian syndrome (PMOS) by global consensus in May 2026. The guideline uses PMOS/PCOS in its recommendations. Clinical content is unchanged.