In PCOS desiring pregnancy, which agent is preferred first-line for ovulation induction?

In PCOS desiring pregnancy, which agent is preferred first-line for ovulation induction?

• A. Clomiphene
• B. Letrozole
• C. Metformin
• D. Gonadotropins

Answer: (B)

Letrozole is preferred first-line for inducing ovulation in PCOS when pregnancy is desired because it has been shown to yield higher live birth rates than clomiphene citrate in multiple studies. Mechanistically, letrozole lowers estrogen production by inhibiting aromatase, which reduces negative feedback on the hypothalamus and pituitary, leading to increased FSH release and better follicle development. It also tends to have a more favorable effect on the endometrium and cervical mucus compared with clomiphene, supporting implantation. While metformin can help some women with insulin resistance, it is generally less effective alone for achieving pregnancy than letrozole. Gonadotropins are effective but carry higher costs and a greater risk of multiple gestations, so they’re usually reserved after failure of oral agents.

Letrozole is preferred first-line for inducing ovulation in PCOS when pregnancy is desired because it has been shown to yield higher live birth rates than clomiphene citrate in multiple studies. Mechanistically, letrozole lowers estrogen production by inhibiting aromatase, which reduces negative feedback on the hypothalamus and pituitary, leading to increased FSH release and better follicle development. It also tends to have a more favorable effect on the endometrium and cervical mucus compared with clomiphene, supporting implantation. While metformin can help some women with insulin resistance, it is generally less effective alone for achieving pregnancy than letrozole. Gonadotropins are effective but carry higher costs and a greater risk of multiple gestations, so they’re usually reserved after failure of oral agents.