Abstract: We included 18 RCTs involving 2952 participants; 15 compared rhCG with uhCG, and 3 compared rhLH with uhCG. The evidence for different comparisons ranged from very low to high quality: limitations were poor reporting of study methods and imprecision. Pharmaceutical companies funded 9 of the 18 studies, and 5 studies did not clearly report funding source. Ongoing pregnancy/live birth There was no conclusive evidence of a difference between rhCG and uhCG (OR 1.15, 95% CI 0.89 to 1.49; 7 RCTs, N = 1136, I2 = 0%, moderate quality evidence) or between rhLH and uhCG (OR 0.95, 95% CI 0.51 to 1.78, 2 RCTs, N = 289, I2 = 0%, very low quality evidence) for ongoing pregnancy/live birth rates. OHSS There was no evidence of a difference between rhCG and uhCG in the incidence of OHSS: moderate to severe OHSS (OR 1.76, 95% CI 0.37 to 8.45; 3 RCTs, N = 417, I2 = 0%, low quality evidence), moderate OHSS (OR 0.78, 95% CI 0.27 to 2.27; 1 RCT, N = 243, I2 = 0%, low quality evidence), mild to moderate OHSS (OR 1.00, 95% CI 0.42 to 2.38; 2 RCTs, N = 320, I2 = 0%, low quality evidence) or undefined OHSS (OR 1.18, 95% CI 0.50 to 2.78; 3 RCTs, N = 495, I2 = 0%, low quality evidence). Likewise, there was no evidence of a difference between rhLH and uhCG in OHSS rates for moderate OHSS (OR 0.82, 95% CI 0.39 to 1.69, 2 RCTs, N = 280, I2 = 5%, very low quality evidence). Other adverse events There was no evidence of a difference in miscarriage rates between rhCG and uhCG (OR 0.72, 95% CI 0.41 to 1.25; 8 RCTs, N = 1196, I2 = 0%, low quality evidence) or between rhLH and uhCG (OR 0.95, 95% CI 0.38 to 2.40; 2 RCTs, N = 289, I2 = 0%, very low quality evidence). For other adverse effects (most commonly injection-site reactions) rhCG was associated with a lower number of adverse events than uhCG (OR 0.52, 95% CI 0.35 to 0.76; 5 RCTS, N = 561; I2 = 67%, moderate quality evidence). However, when we used a random-effects model due to substantial statistical heterogeneity, there was no evidence of a difference between the groups (OR 0.56, 95% CI 0.27 to 1.13). Only one study comparing rLH and uhCG reported other adverse events, and it was impossible to draw conclusions. We conclude that there is no evidence of a difference between rhCG or rhLH and uhCG for live birth or ongoing pregnancy rates or rates of OHSS.

Plain-language summary: We found 18 studies in 2952 women undergoing IVF or ICSI. Fifteen trials in 2473 women compared rhCG with uhCG, and three trials in 479 women compared rLH with uhCG. Women in the studies were 18 to 45 years old, with regular menstrual cycles and no history of OHSS. Types of subfertility included tubal disease, endometriosis, unexplained infertility and male factor infertility. Pharmaceutical companies funded 9 of the 18 studies; 4 studies were free of commercial funding, and the remaining 5 studies did not clearly report a funding source. The evidence is current to April 2015. There was no evidence of a difference between rhCG and uhCG or between RhLH and uhCG in rates of live birth/ongoing pregnancy or OHSS. Studies did not report much evidence on adverse events other than OHSS, and the evidence they did report was inconclusive. For the comparison 'rhCG versus uhCG', the evidence was of moderate quality for ongoing pregnancy/live birth rate and of low quality for incidence of OHSS. The main limitation of the evidence was lack of precision (i.e. study size was too small to rule out the role of chance). For the comparison 'rLH versus uhCG', the evidence was of very low quality for both ongoing pregnancy/live birth rate and incidence of OHSS. The main limitations of the evidence were lack of precision and poor reporting of study methods.