Table 2 Pooled odds ratios of the occurrence of maternal pregnancy complications by study characteristics
From: Fetal sex and maternal pregnancy outcomes: a systematic review and meta-analysis
Subgroup | No. of studies | Participants | OR (95% CI) | p value for heterogeneity |
|---|---|---|---|---|
Gestational hypertension | ||||
 Geographical location | ||||
  Western | 11 | 5.511.340 | 1.02 (0.98;1.06) | 0.3 |
  Non-Western | 5 | 125.016 | 0.99 (0.95;1.02) | |
 No of participants | ||||
  < 10.000 | 8 | 30.853 | 1.01 (0.98;1.05) | 0.47 |
  ≥ 10.000 | 8 | 5.605.503 | 0.96 (0.85;1.10) | |
 Study design | ||||
  Case-control | 1 | 294 | 0.54 (0.26;1.14) | 0.19 |
  Retrospective cohort | 11 | 5.508.737 | 1.02 (0.98;1.05) | |
  Prospective cohort | 4 | 127.325 | 0.98 (0.89;1.08) | |
 Quality score | ||||
  < 7 | 11 | 5.489.916 | 1.03 (1.01;1.05) | < 0.001 |
  ≥ 7 | 5 | 146.440 | 0.92 (0.81;1.05) | |
Pre-eclampsia (total) | ||||
 Geographical location | ||||
  Western | 15 | 3.472.444 | 1.03 (1.00;1.05) | < 0.001 |
  Non-Western | 14 | 541.647 | 0.90 (0.83;0.97) | |
 No. of participants | ||||
  < 10.000 | 13 | 39.373 | 0.92 (0.78;1.08) | 0.84 |
  ≥ 10.000 | 16 | 3.974.718 | 0.97 (0.94;1.01) | |
 Study design | ||||
  Case-control | 7 | 2.174 | 0.86 (0.64;1.16) | 0.12 |
  Retrospective cohort | 18 | 3.884.545 | 0.98 (0.95;1.02) | |
  Prospective cohort | 4 | 127.372 | 0.90 (0.81;1.00) | |
 Quality score | ||||
  < 7 | 22 | 1.538.622 | 0.97 (0.93;1.02) | 0.71 |
  ≥ 7 | 7 | 2.475.469 | 0.95 (0.88;1.02) | |
Eclampsia | ||||
 Geographical location | ||||
  Western | 5 | 4.820.821 | 1.02 (1.00;1.04) | 0.05 |
  Non-Western | 2 | 110.156 | 0.82 (0.57;1.18) | |
 No of participants | ||||
  < 10.000 | 1 | 434 | 0.65 (0.45;0.94) | 0.02 |
  ≥ 10.000 | 6 | 4.930.534 | 1.01 (0.99;1.04) | |
 Study design | ||||
  Case-control | 1 | 434 | 0.65 (0.45;0.95) | 0.01 |
  Retrospective cohort | 5 | 4.820.821 | 0.95 (0.88;1.02) | |
  Prospective cohort | 1 | 109.722 | 1.02 (1.00;1.04) | |
 Quality score | ||||
  < 7 | 6 | 4.920.963 | 1.00 (0.95;1.04) | 0.84 |
  ≥ 7 | 1 | 10.014 | 0.92 (0.42;2.01) | |
Gestational diabetes | ||||
 Geographical location | ||||
  Western | 16 | 1.632.560 | 1.03 (1.01;1.05) | 0.17 |
  Non-Western | 8 | 379.756 | 1.09 (1.02;1.15) | |
 No of participants | ||||
  < 10.000 | 10 | 15.111 | 1.16 (1.02;1.33) | 0.14 |
  ≥ 10.000 | 14 | 1.997.205 | 1.04 (1.02;1.06) | |
 Study design | ||||
  Case-control | 5 | 1.062 | 1.15 (0.94;1.40) | 0.66 |
  Retrospective cohort | 12 | 2.009.749 | 1.04 (1.02;1.06) | |
  Prospective cohort | 7 | 1.505 | 1.16 (1.01;1.33) | |
 Quality score | ||||
  < 7 | 18 | 1.091.263 | 1.05 (1.02;1.09) | 0.75 |
  ≥ 7 | 6 | 921.053 | 1.04 (1.01;1.07) | |
Placental abruption | ||||
 Geographical location | ||||
  Western | 7 | 2.876.604 | 1.03 (0.86;1.23) | 0.45 |
  Non-Western | 6 | 227.068 | 1.10 (0.93;1.31) | |
 No of participants | ||||
  < 10.000 | 4 | 7.801 | 1.31 (0.85;2.02) | 0.4 |
  ≥ 10.000 | 9 | 3.095.871 | 1.04 (0.90;1.22) | |
 Study design | ||||
  Case-control | 2 | 1.090 | 2.34 (1.25;4.35) | 0.08 |
  Retrospective cohort | 10 | 2.992.860 | 1.05 (0.90;1.22) | |
  Prospective cohort | 1 | 109.722 | 0.98 (0.83;1.15) | |
 Quality score | ||||
  < 7 | 6 | 224.641 | 1.21 (0.96;1.51) | 0.2 |
  ≥ 7 | 7 | 2.879.031 | 1.01 (0.85;1.19) | |