Metformin Treatment Before in Vitro Fertilization (IVF) in Women With Ultrasound Evidence of Polycystic Ovaries

Inclusion Criteria: * Women attending with ovulatory PCO due to undergo IVF/ICSI treatment. * First or second cycle of IVF/ICSI. * If previously on metformin, a minimum one month washout period was required. * Polycystic ovaries diagnosed by ultrasound presence of ≥12 follicles measuring 2-9 mm in diameter in at least one ovary and/or increased ovarian volume (≥10 ml). * Written informed consent. Exclusion Criteria: * Clinical manifestations of PCOS, including any of the following: 1. Oligo- or amenorrhoea with cycles ≥42 days apart. 2. Anovulation with mid-luteal progesterone \<16 nmol/L. 3. Biochemical hyperandrogenism with serum testosterone ≥3.5 nmol/L and/or free androgen index \>5 (FAI = \[total testosterone/SHBG\] x 100). 4. Clinical hyperandrogenism with hirsutism or acne requiring treatment at least weekly. * Age \>38 years. * BMI \>35 kg/m2. * Basal FSH \>12 IU/L. * Liver disease or ALT \>80 IU/L. * Renal disease, or creatinine \>130 nmol/L. * Alcoholism or drug abuse. * Diabetes mellitus (evaluated by fasting glucose \>6.7mmol/L). * Per oral steroid treatment in last month. * Cimetidine, anticoagulation, erythromycin, or other macrolides in last month. * Hyperprolactinemia (Prolactin \>700 mIU/L). * Abnormal thyroid function tests (TSH outside of laboratory normal range). * Congenital adrenal hyperplasia.