Comparison of pregnant and non-pregnant women with clomiphene resistant polycystic ovary syndrome in treatment with metformin and letrozole

Polycystic ovary syndrome (PCOS) is one of the most common causes of anovulatory infertility. Clomiphen citrate (CC) is the first line therapy for women with infertility and PCOS. These patients usually respond to clomiphene citrate in doses between 50-100 mg/day. However, fialure of the patient to respond to a dosage of 150 mg/day of clomiphene citrate is considered as clomiphene resistant. The aim of this study was to compare between pregnant and non-pregnant women in cases of PCOS patients with CC resistant. Meanwhile, we evaluated ovulatory rate, pregnancy rate and live birth rates. We studied 106 CC-resistant PCOS patients who attended to Amir-Al- Momenin Hospital (Semnan, Iran) during the years 2005-2008. After an initial 6-8 weeks of metformin (1500mg daily: 500mg q8h), they received 2.5mg letrozole for 5 days starting on cycle day 3. If they failed to show ovluation with 2.5mg letrozole, doses were increased 5 and 7.5 mg daily in the subsequent cycles. One patient developed generalized rash with metformin and excluded from the study. 14 of 105 patients (13.33%) conceived with metformin alone. Overall, ovulation rate was 83.91(91.2%). Overall, pregnancy rate was 60/105 (57.14%) with 45 (74.9%) full term pregnancies, 10 (16.7%) abortions and 5 (8.3%) preterm births. The only significant difference between the responder and non-responder was found in the age of patients (P=0.008). No significant differences were found in BMI, period of infertility, menstrual pattern, hirsutism, pictures of PCO in one or two ovaries in sonography, LH, and FSH or LH/FSH ratio. Combination of metformin with incremental doses of letrozole associated with a good pregnancy rate in CC-resistant PCOS patients. The treatment seems especially more effective in young weman.