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”).