Abu Hashim 2010a.

Methods	Prospective randomised trial conducted in Egypt
Participants	260 women attending fertility clinics. Mean age of women in letrozole group was 27.3 ± 2.6 years and in the LOD group was 26.4 ± 2.4 years Inclusion: Clomiphene‐resistant PCOS, patent fallopian tubes assessed by hysterosalpingography, normal semen analysis from partner, normal serum prolactin, thyroid stimulating hormone and 17‐hydroyprogesterone Exclusion: Other causes of infertility, age > 40 years, BMI > 35, contraindications to anaesthesia, previous history of LOD, and having received metformin, gonadotrophin, other hormonal drugs or OCP in preceding 6 months. Women intending to start a diet or a specific programme of physical activity were also excluded
Interventions	Letrozole 2.5 mg orally daily from day 3 of the menses for 5 days for 6 cycles (n = 128), versus LOD ‐ each ovary was cauterised at 4 points and women were followed up for 6 months (n = 132)
Outcomes	Biochemical pregnancy, clinical pregnancy, ovulation, miscarriage, live birth rates, endometrial thickness
Notes