Fig. 2

Meta-analyses on the association between fetal sex and maternal pregnancy complications. The boxes are proportional to the weight of each study in the analysis, and the lines represent their 95% confidence intervals (CIs). Size of data markers are proportional to the inverse of the variance of the effect estimate. The open diamond represent the pooled odds ratio, and its width represents its 95% CI. The summary estimates presented were calculated using random-effects models (D + L) and fixed effects (I + V). Assessment of heterogeneity: gestational hypertension (I² = 74,8%, p < 0.001) (a); total pre-eclampsia (I² = 81,8%, p < 0.001) (b); preterm pre-eclampsia (I² = 93,5%, p < 0.001) (c); term pre-eclampsia (I² = 7,1%, p = 0.37) (d); postterm pre-eclampsia (I² = 84.4%, p = 0.011) (e); eclampsia (I² = 47.0%, p = 0.08) (f); gestational diabetes, (I² = 36,3%, p = 0.03) (g); placental abruption (I² = 92.9%, p < 0.001) (h)