Table 3 The results of meta-regression subgroup analyses for primary outcomes
Characteristic | Subgroup analyses | Meta-regression | |||||||
|---|---|---|---|---|---|---|---|---|---|
No. of subjects | No. of studies | Random-effects RR (95% CI) | Heterogeneity | Coefficient | p-value | I2resid | Adj R2 | ||
I2 | P | ||||||||
Clinical pregnancy | |||||||||
Age | |||||||||
 < 33.3 years | 1800 | 8 | 0.96 (0.82, 1.13) | 42.1% | 0.097 | 0.045 | 0.270 | 60.38% | 0.71% |
  ≥ 33.3 years | 3821 | 16 | 1.27 (1.08, 1.50) | 62% | <  0.005 | ||||
Duration of infertility | |||||||||
 < 5. 6 years | 2103 | 8 | 1.27 (0.95, 1.71) | 77.6% | <  0.001 | 0.072 | 0.523 | 76.70% | −5.06% |
  ≥ 5. 6 years | 62 | 1 | 1.60 (0.59, 4.35) | / | / | ||||
Percentage of primary infertility | |||||||||
 < 50% | 518 | 2 | 1.11 (0.59, 2.10) | 82.7% | 0.016 | 1.252 | 0.203 | 71.19% | 2.77% |
  ≥ 50% | 2588 | 8 | 1.18 (0.92, 1.52) | 73.7% | <  0.001 | ||||
Percentage of repeated IVF cycle | |||||||||
 < 50% | 1279 | 3 | 0.86 (0.75, 1.00) | 0% | 0.63 | 1.59 | < 0.001 | 0% | 100% |
  ≥ 50% | 2099 | 8 | 1.60 (1.28, 2.00) | 39% | 0.12 | ||||
No. of embryos transferred | |||||||||
 < 1.9 | 1875 | 4 | 0.96 (0.79, 1.16) | 46% | 0.14 | 0.219 | 0.305 | 65.92% | 0.79% |
  ≥ 1.9 | 3186 | 16 | 1.24 (1.03, 1.49) | 67.3% | <  0.001 | ||||
Type of acupunture invention | |||||||||
 Electroacupuncture | 958 | 7 | 1.30 (0.96, 1.75) | 56.5% | 0.032 | 0.066 | 0.713 | 65.29% | −6.38% |
 Manual acupuncture | 5187 | 21 | 1.21 (1.04, 1.40) | 67.8% | <  0.001 | ||||
No. of acupuncture treatments | |||||||||
 one session | 3962 | 16 | 1.06 (0.92, 1.21) | 61.1% | 0.001 | 0.248 | 0.002 | 48.40% | 51.90% |
  ≥ two sessions | 2055 | 12 | 1.60 (1.32, 1.92) | 24.9% | 0.199 | ||||
Type of control group | |||||||||
 Sham or placebo acupuncture control | 3060 | 11 | 1.14 (0.94, 1.39) | 66.6% | 0.001 | −0.109 | 0.466 | 62.34% | −0.25% |
 No acupuncture invention control | 3084 | 17 | 1.28 (1.08 1.52) | 60.3% | 0.001 | ||||
Live birth | |||||||||
Age | |||||||||
 < 33.3 years | 895 | 3 | 0.96 (0.59, 1.58) | 77% | 0.013 | 0.026 | 0.693 | 68.74% | −13.18% |
  ≥ 33.3 years | 3179 | 10 | 1.18 (0.96, 1.45) | 63% | 0.003 | ||||
Duration of infertility | |||||||||
 < 5. 6 years | 1748 | 5 | 1.03 (0.76, 1.40) | 71.6% | 0.007 | 0.157 | 0.712 | 75.35% | −20.26% |
  ≥ 5. 6 years | / | / | / | / | / | ||||
Percentage of primary infertility | |||||||||
 < 50% | 518 | 2 | 1.07 (0.62, 1.83) | 69.7% | 0.069 | 0.497 | 0.658 | 71.40% | −43.04% |
  ≥ 50% | 2054 | 4 | 1.00 (0.74, 1.36) | 71.7% | 0.014 | ||||
Percentage of repeated IVF cycle | |||||||||
 < 50% | 1005 | 2 | 0.81 (0.67, 1.01) | 0% | 0.673 | 1.256 | 0.046 | 32.78% | 87.90% |
  ≥ 50% | 1688 | 5 | 1.42 (1.05, 1.92) | 45% | 0.12 | ||||
No. of embryos transferred | |||||||||
 < 1.9 | 1865 | 4 | 0.87 (0.74, 1.02) | 0% | 0.604 | 0.386 | 0.163 | 62.55% | 7.83% |
  ≥ 1.9 | 2397 | 10 | 1. 27 (1.00, 1.62) | 66.0% | 0.002 | ||||
Type of acupunture invention | |||||||||
 Electroacupuncture | 149 | 1 | 1.90 (1.05, 3.42) | / | / | 0.534 | 0.226 | 61.92% | 9.04% |
 Manual acupuncture | 4323 | 14 | 1.11 (0.93, 1.31) | 62.0% | 0.001 | ||||
No. of acupuncture treatments | |||||||||
 one session | 3080 | 11 | 1.13 (0.92, 1.39) | 70.4% | <  0.001 | 0.099 | 0.654 | 64.01% | −7.71% |
  ≥ two sessions | 1485 | 5 | 1.22 (0.93, 1.60) | 23.2% | 0.266 | ||||
Type of control group | |||||||||
 Sham or placebo acupuncture control | 2480 | 6 | 1.01 (0.80, 1.27) | 63.8% | 0.017 | −0.213 | 0.274 | 60.40% | 7.21% |
 No acupuncture invention control | 1992 | 9 | 1.26 (0.99, 1.60) | 58.3% | 0.014 | ||||