The quality of evidence is downgraded by study limitations (unclear allocation concelament and lack blinding in half of the studies) and by imprecise results (few patients and outcome events).
A Cochrane review [Abstract] 1 included 5 studies with a total of 264 subjects comparing gonadotrophins plus metformin versus gonadotrophins in anovulation due to polycystic ovary syndrome (PCOS). The gonadotrophin used was recombinant follicle stimulationg hormone (FSH) in 4 studies and highly purified FSH in 1 study. Metformin plus FSH was associated with a higher live birth rate when compared with FSH (table T1). This suggests that if the chance of live birth after FSH is assumed to be 27%, then the chance after addition of metformin would be between 32% and 60%. There were no difference in rates of multiple pregnancy, miscarriage, or ovarian hyperstimulation syndrome.
| Outcome | Relative effect (95% CI) OR | Assumed risk - Gonadotrophins plus placebo | Intervention - Gonadotrophins plus metformin | Number of participants (studies) |
|---|---|---|---|---|
| Live birth rate Follow-up: 3-6 months | 2.31 (1.24 to 4.33) | 267 per 1000 | 457 per 1000,190 more per 1000 (42 to 345) | 180 (2) |
| Multiple pregnancy rate | 0.55(0.15 to 1.95) | 52 per 1000 | 26 per 1000,23 fewer per 1000 (44 fewer to 25 more) | 232 (4) |
| Ongoing pregnancy rate | 2.46 (1.36 to 4.46) | 217 per 1000 | 393 per 1000,189 more per 1000 (57 to 336) | 232 (4) |
| Clinical pregnancy rate | 2.51 (1.46 to 4.31) | 252 per 1000 | 444 per 1000,206 more per 1000 (78 to 340) | 264 (5) |
Date of latest search: 2018-06-04
Primary/Secondary Keywords