Ibrahim 2017.

Study characteristics
Methods	Randomised controlled trial Duration of the trial: quote: "The study was conducted during the period from 1st August 2015 to 30th March 2016.“
Participants	Inclusion criteria: quote: "age >20 and <35 years old, patients were diagnosed to have PCOS criteria of diagnosis of PCO. Normal HSG and their partners had normal semen analysis according to WHO criteria (WHO, 2010) and CC‐resistant. If patients fail to respond to 150 mg/day for 5 days for 3 consecutive cycles, they are considered as CC‐resistant." Exclusion criteria: quote: "Age less than 20 yr or more than 35 yr, non‐PCOS, and those Patients with poor ovarian reserve i.e. hyperprolactinaemia, hypo and hyperthyroidism, diabetic patients and Cushing’s syndrome were excluded, non‐classical congenital adrenal hyperplasia, current or previous (within the last 6 months) use of oral contraceptives, glucocorticoids, antiandrogens, antidiabetic or antiobesity drugs, or other hormonal drugs, any subject was affected by either neoplastic, metabolic, hepatic, or cardiovascular disorder or other concurrent medical illness (i.e. diabetes, renal disease, or malabsorptive disorders) were excluded, pelvic diseases, previous pelvic surgery, suspected peritoneal factor infertility, tubal infertility and male factor infertility were excluded with a hysterosalpingogram and with semen analysis, respectively." Number of women randomised: 80 women, 40 within each group Number of women analysed: 80 women, 40 within each group Number of withdrawals/exclusions/loss to follow‐up and reasons: none Number of centres: single‐centre trial Age (y): LOD group 28.8 ± 3.1 versus letrozole group 29.7 ± 3.7 BMI (kg/m²): LOD group 29.1 ± 1.6, letrozole group 29.2 ± 1.7 Duration of infertility (y): no mean ± SD reported Country: Egypt
Interventions	Group A: quote: "In group A, laparoscopy was performed under intravenous general anaesthesia with the patient in a supine position. A 5 mm incision was made in the navel, through which a long sheath punctured into the abdominal cavity, and the inflatable pneumoperitoneum was placed. Another two 5‐mm incisions were made on the right and left lower abdomen and the surgical instruments were inserted into the abdominal cavity. The patient was adjusted into a position with the head high up, the pelvic organs were exposed and a comprehensive exploration of the pelvic organs was made, focusing on the structure and position of the adjacent organs of the bilateral ovaries. Once immobilized, each ovary was cauterized at 4–6 points, using a monopolar electrosurgical needle, according to the size of each ovary. Following cauterization, a bilateral tubal hydrotubation with methylene blue was performed. During the procedure. The pelvis was irrigated using physiological saline. Ringer’s solution plus dexamethasone was added into the abdominal cavity to avoid adhesion. The total duration of the procedure, as well as any intra‐operative or post‐operative complications, was noted." Group B: quote: "In group B, 2.5 mg twice daily LE oral tablets were administered on the 3rd day of menses and then every day for 5 days. Treatment was repeated for up to six cycles if the patient failed to ovulate, the patients were followed‐up for 6 months after the treatment in both groups."
Outcomes	Pregnancy rate, abortion rate, ovulation, regular cycles, ovarian volume, antral follicle count
Notes	Ethical approval: trial was approved by Minia University Ethical Committee Informed consent: quote: “Informed consent was obtained from all participating women after the nature and purpose of the study had been explained to them and were fully understood” Source of funding: quote: “We have not received any funding from any corporate body or pharmaceutical company. “ Power calculation: none reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomization was achieved via the use of a randomisation number allocated prior to dosing, once eligibility had been determined, and a randomisation schedule was produced by an interactive voice response system vendor."
Allocation concealment (selection bias)	Low risk	Quote: "randomisation schedule was produced by an interactive voice response system vendor"
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants were not blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Once the patients had been allocated to one of the two groups, the treatment was revealed to the investigator; however, the doctor responsible for performing the transvaginal ultrasound follow up assessment was blinded to the treatment groups."
Incomplete outcome data (attrition bias) All outcomes	Low risk	All women randomised were also analysed.
Selective reporting (reporting bias)	Unclear risk	We found no reporting of outcomes in a trial protocol or Methods section
Other bias	Low risk	None