Letrozole Step up Protocol for Ovulation Induction in Infertile Women With Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) is the largest single cause of anovulatory infertility. Letrozole, an aromatase inhibitor, has been regarded as the first-line drug for ovulation induction in PCOS patients. The conventional protocol of letrozole includes the administration of a fixed dose of letrozole (2.5 -7.5 mg) for 5 days. Few recent studies have shown that the step-up letrozole protocol causes more follicles to grow, induces more ovulation, and increases the pregnancy rate. This study aimed to compare the effect of the letrozole step-up and conventional fixed-dose protocol for ovulation induction in infertile women with PCOS.

Methods: This open-label randomized controlled study was conducted on a total of 70 infertile PCOS women eligible for ovulation induction. Treatment with letrozole started from day 2-3 of menstruation or withdrawal bleeding. They were randomly allocated into two groups. The experimental group (n=35) was given step-up letrozole, one (2.5 mg), two (5 mg), three (7.5 mg), and four (10 mg) tablets, single dose sequentially for 4 days. The comparator group (n=35) received conventional fixed-dose letrozole, two (5mg) tablets daily for 5 days. The outcome variables were the number of participants having a mature follicle by day 12-16 of the cycle and the number of mature follicles on the day of trigger.

Inclusion criteria

• PCOS women with subfertility
• Selected for ovulation induction

Exclusion criteria

• Body mass index (BMI) ˂18 and ≥30 kg/m2,
• Women with other infertility factors (endometriosis, suspected tubal factor, and uterine causes of infertility)
• Male factor infertility