Table 3 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. studies | Participants | OR (95% CI) | p value for heterogeneity |
|---|---|---|---|---|
| Gestational hypertension | ||||
| Geographical location | ||||
| Western | 12 | 5.511.490 | 1.02 (0.98;1.06) | 0.29 |
| Non-Western | 5 | 125.016 | 0.99 (0.95;1.02) | |
| No of participants | ||||
| < 10.000 | 9 | 31.003 | 0,98 (0.86;1.10) | 0.56 |
| ≥ 10.000 | 8 | 5.605.503 | 1,01 (0.98;1.05) | |
| Study design | ||||
| Case-control | 2 | 444 | 0.86 (0.35;2,07) | 0.57 |
| 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 | 6 | 146.590 | 0.94 (0.82;1.06) | |
| Pre-eclampsia (total) | ||||
| Geographical location | ||||
| Western | 22 | 3.970.495 | 1.02 (1.00;1.05) | 0,23 |
| Non-Western | 15 | 636.671 | 0.93 (0.83;1,04) | |
| No of participants | ||||
| < 10.000 | 18 | 42.194 | 0.92 (0.82;1.04) | 0.27 |
| ≥ 10.000 | 19 | 4.548.703 | 1,00 (0.96;1.03) | |
| Study design | ||||
| Case-control | 9 | 18.593 | 0.94 (0.75;1.02) | 0.50 |
| Retrospective cohort | 24 | 4.461.201 | 1,00 (0.96;1.04) | |
| Prospective cohort | 4 | 127.372 | 0.90 (0.81;1.00) | |
| Quality score | ||||
| < 7 | 22 | 1.539.869 | 0.97 (0.93;1.02) | 0.71 |
| ≥ 7 | 7 | 3.067.297 | 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 | 18 | 1.728.325 | 1.03 (1.01;1.05) | 0.13 |
| Non-Western | 10 | 380.388 | 1.07 (1.03;1.12) | |
| No of participants | ||||
| < 10.000 | 13 | 16.484 | 1.12 (1.02;1.24) | 0.13 |
| ≥ 10.000 | 15 | 2.092.229 | 1.04 (1.02;1.06) | |
| Study design | ||||
| Case-control | 6 | 1.092 | 1.15 (0.95;1.39) | 0.66 |
| Retrospective cohort | 14 | 2.105.377 | 1.04 (1.02;1.06) | |
| Prospective cohort | 8 | 2.246 | 1.16 (1.02;1.31) | |
| Quality score | ||||
| < 7 | 21 | 1.092.636 | 1.05 (1.02;1.09) | 0.75 |
| ≥ 7 | 7 | 1.016.077 | 1.04 (1.02;1.06) | |
| 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) | |