Assessment of potential confounders
Potential confounding factors were considered based on whether they could influence both prenatal maternal anxiety and child development outcomes, and were included in the adjusted model if associated with the exposure (prenatal maternal anxiety) and one of the two outcome measures. The following variables were considered to be potential confounders: alcohol consumption during pregnancy (coded as 0 for “never” and 1 for “more than once a month”); smoking in pregnancy (coded as 0 for “never”, 1 for “sometimes”, and 2 for “daily”); marital status (coded as 0 for “married/living together” and 1 for “single”); and maternal education (coded as 0 for “higher university degree, and “1” for +4 years)”, 1 for “college/university (3 years), 2 for “college (1-2 years)”, and 3 for “secondary school”). The following variables extracted from the MBRN were also controlled for: maternal age as a continuous variable; parity coded as itself, where greater than or equal to 4 was coded as 4+; birth complications (coded as 1 for “yes” or 0 for “no”); child’s sex (coded as 0 for “girl” and 1 for “boy”); and preeclampsia (coded as 0 for “no” and 1 for “yes”).