Statistical analysis
Continuous variables were expressed as mean and standard deviation for normally distributed data and median and inter-quartile range for skewed data. Categorical variables were expressed as counts and percentages. Chi-square tests with Bonferroni post hoc were used to compare proportions among categorical variables. Mann–Whitney U tests were used to analyze the non-normal distribution variables. Binary logistic regression was conducted to analyze the association with adverse fetal outcomes (combining induced abortions, SFLs, preterm births, and MCMs) using pregnancy planning, age at conception, appropriate folic acid supplementation, whether taking VPA during pregnancy, and GTCS frequency during pregnancy as covariates. Two-tailed P values < 0.05 were considered statistically significant. In the post hoc of the chi-square test,P boundary value (α’) was adjusted according to the Bonferroni method. Statistical analysis was performed using SPSS 24.0 (IBM Inc.).