Risk factors | Number of cases | Summary associations (p-value) per random-effects calculations | Small-study effects (p-value for Egger) | Excess of significance bias (p-value) | Prediction intervals | Largest study nominally significant (p-value) | Heterogeneity (I2%) | Sensitivity analysis | Classification |
---|---|---|---|---|---|---|---|---|---|
Maternal asthma | 1451 | 0.0002 | 0.931 | 0.102 | 1.05–1.62 | 0.667 | 44.8 | T = 1.212, G = 1.719 | Suggestive |
Maternal pre-pregnancy BMI Underweight Overweight Obese | 773 666 1036 | 0.0036 0.0007 0.0002 | 0.844 0.470 0.599 | 0.252 0.002 0.277 | 0.51–16.03 0.75–0.93 0.81–0.94 | < 0.01 0.007 < 0.01 | 55.2 0.0 28.2 | T = 1.389, G = 2.124 T = 1.389, G = 2.124 T = 1.333, G = 2.001 | Weak Weak Suggestive |
Prior cesarean section | 29,001 | 0.0003 | 0.140 | 0.002 | 0.85–6.50 | < 0.0001 | 0.0 | T = 2.160, G = 3.743 | Suggestive |
Cocaine use | 1123 | < 0.0001 | 0.953 | 0.003 | 2.39–5.68 | 0.001 | 0.0 | T = 3.199, G = 5.853 | Suggestive |
Endometriosis | 33,378 | 0.0001 | 9.929 | 0.238 | 0.94–2.50 | < 0.0001 | 82 | T = 1.454, G = 2.266 | Suggestive |
Fetal sex | 21,396 | 0.7710 | 0.544 | 0.741 | 0.65–1.62 | < 0.001 | 92.9 | T = 0.995, G = Nan | NS |
Chronic hypertension | 1539 | < 0.0001 | 0.046 | 0.042 | 1.67–3.40 | 0.0006 | 0.0 | T = 2.414, G = 4.262 | Suggestive |
preeclampsia | 5622 | 0.0338 | 0 | 0.901 | 1.04–2.50 | 0.04 | 0.0 | T = 1.379, G = 2.102 | Weak |
Uterine leiomyoma | 5137 | 0.0036 | 0.915 | 0.602 | 0.51–16.03 | < 0.01 | 82.6 | T = 2.182, G = 3.788 | Weak |
Marijuana use | 488 | 0.0002 | 0.940 | 0.003 | 1.30– 2.37 | 0.026 | 0.0 | T = 1.614, G = 2.609 | Weak |
Advanced maternal age | 215,829 | < 0.0001 | 0.035 | 0.291 | 1.12–1.51 | < 0.0001 | 88.3 | T = 1.608, G = 2.598 | Suggestive |
Maternal smoking | 26,038 | < 0.0001 | 0.477 | 0.001 | 1.49–2.32 | < 0.01 | 65.8 | T = 1.790, G = 2.980 | Suggestive |
Use of ART | 75,983 | 0.0009 | 0.761 | 0.772 | 0.70–3.88 | < 0.0001 | 36 | T = 1.207, G = 1.708 | Suggestive |