Publication:

Road to fertility: comparison of letrozole and clomiphene citrate-estradiol valerate for ovulation induction in female with unexplained infertility to see ovulation and conception rate

Background Clomiphene citrate was considered as first line of treatment for ovulation and induction in patients with unexplained infertility, but there are differences in results which can be explained by anti-estrogenic effect of CC resulting in estrogen receptor depletion. Letrozole is potent non-steroidal aromatase inhibitor which increases gonadotrophin secretion with ovarian follicle stimulation. Research question was that which drug is more efficacious for ovulation and induction in patients with unexplained infertility.

Methods This comparative study was conducted at OBGYN OPD of RMCH and RC, Kanpur. Patients were 50 females with unexplained infertility randomly divided into 2 groups. Group A received letrozole 2.5 mg from D3-D7 of menstruation. Group B received CC 50 mg from D3-D7 plus 2 mg estradiol valerate BD on D8-D14 of menstruation. Female aged 18-35 years with complete fertility workup i.e. D3 FSH, LH, prolactin, serum TSH, HSG, USG-pelvis, mid luteal phase progesterone, semen analysis within normal limits are included in study. Patients with male infertility, hyperprolactinemia, thyroid disorders and BMI>30 kg/m2 were excluded.

Results There was statistically significant difference in endometrial thickness (ET) between two groups, (p value <0.03) as mean ET was 9.3±1.7 in group A (L) and 8.3±1.5 in group B (CC+E). The number of follicles after stimulation were better with CC+E 2.9±1.1 and L 2.1±1.2 showing statistically significant difference with p value <0.01 but clinical pregnancy rate was higher with letrozole as compared to CC-E without statistically significant difference.

Conclusions Letrozole has better effect on endometrial thickness with statistically significant difference. CC+E had advantage towards multifollicular development with statistically significant difference, but there was no significant difference in case of clinical pregnancy rate, abortion, ectopic, multiple gestation.