Table 1.

Definition of covariate variables

Variable	Definition
Low-income-cut-off (LICO) [16]	A measure of the income threshold below which a family will likely spend 20 percentage points more than the average family on food, shelter and clothing
Medical condition prior to pregnancy	Yes in response to the question “Prior to your pregnancy, did you develop any medical conditions or health problems that required you to take medication for more than 2 weeks, have special care, or extra tests during pregnancy?”
Medical condition during pregnancy	Yes in response to the question “During your pregnancy, did you develop any new medical conditions or health problems that required you to take medication for more than 2 weeks, have special care, or extra tests?”
Depression prior to pregnancy	Yes in response to the question “Before your pregnancy, had you ever been prescribed anti-depressants or been diagnosed with depression?
Short stature	Height of less than 1.55 metres (5 feet 2 inches)