Letrozole-clomiphene citrate combo improves ovulation rate in infertile women with PCOS
Combination therapy with letrozole and clomiphene citrate (CC) yields a higher ovulation rate in women with infertility and polycystic ovary syndrome (PCOS) compared with letrozole alone, according to the results of an open-label trial.
The trial randomized 70 women aged 18–40 years with a diagnosis of infertility and PCOS, as defined by the Rotterdam criteria, and no other known cause of infertility to receive either 2.5 mg letrozole alone (n=35) or the combination of 2.5 mg letrozole and 50 mg CC daily (n=35) on cycle days 3–7 for one treatment cycle.
With respect to the primary outcome, the combination therapy was associated with a higher rate of ovulation, defined as mid-luteal serum progesterone concentration ≥3 ng/mL, relative to letrozole monotherapy (77 percent vs 43 percent; rate ratio, 1.80; 95 percent CI, 1.18–2.75; p=0.0068).
On the other hand, there were no significant between-group differences in secondary outcomes such as conception, pregnancy and live birth. Researchers noted that a much larger sample size would be needed to detect differences in these outcomes.
None of the women had multiple-gestation pregnancies. Among those who conceived, rates of pregnancy loss were similar in the two treatment groups. Among those who ovulated, endometrial thickness, median number of follicles >15 mm, largest follicle size and serum progesterone level were also comparable.
The findings indicate that the combination of letrozole and CC is superior to letrozole alone for inducing ovulation in the setting of infertility treatment in women with PCOS, researchers said. This suggests that the combination therapy represents an alternate low-risk, low-cost infertility treatment that offers improved ovulation rates.