Table 3. Characteristics of 2720 gestational diabetes mellitus cases and 5626 controls included in this meta-analysis.
| First author | Year | Country | Control source | Genotyping method | NOS Score | Case (n) | Control (n) | HWE (P) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Total | GG | GT | TT | Total | GG | GT | TT | |||||||
| Lauenborg | 2009 | Denmark | Hospital-based | TaqMan assay | 6 | 274 | 115 | 132 | 27 | 2334 | 1138 | 972 | 224 | 0.433 |
| Cho | 2009 | Korea | Population-based | TaqMan assay | 6 | 857 | 389 | 365 | 103 | 627 | 313 | 257 | 57 | 0.685 |
| Wang | 2011 | China | Hospital-based | TaqMan assay | 8 | 705 | 371 | 278 | 56 | 1025 | 605 | 361 | 59 | 0.596 |
| Chon | 2013 | Korea | Hospital-based | PCR-RFLP | 6 | 94 | 57 | 30 | 7 | 41 | 15 | 24 | 2 | 0.053 |
| Popova | 2017 | Russia | Hospital-based | PCR-RFLP | 7 | 278 | 120 | 134 | 24 | 179 | 77 | 76 | 26 | 0.310 |
| Tarnowski | 2019 | Poland | Hospital-based | TaqMan assay | 7 | 207 | 105 | 76 | 26 | 204 | 89 | 93 | 22 | 0.753 |
| Current study | 2020 | China | Hospital-based | TaqMan assay | 6 | 305 | 168 | 115 | 22 | 1216 | 608 | 488 | 120 | 0.131 |
Abbreviations: HWE, Hardy–Weinberg equilibrium; NOS, Newcastle–Ottawa Scale; PCR-RFLP, polymerase chain reaction-restriction fragment length polymorphism.