Table 4. Association between birth order, having an ObOw sibling and childhood obesity or overweight.

	ObOw (BMI z score > 2) b
	OR	95%CI
Sibling rank by having or not ObOw siblings a
First-born child without ObOw siblings	0.51	0.19–1.36
First-born child with ObOw siblings	1.01	0.62–1.65
Second-born child without ObOw siblings	1.23	1.03–1.46
Second-born child with ObOw siblings	2.59	1.27–5.30
Third-born or younger child without ObOw siblings	1.06	0.80–1.42
Third-born or younger child with ObOw siblings	4.23	1.32–13.61

a:Reference: a child without siblings

b: Adjusted for gender, birthweight, health status of children, duration of breastfeeding, maternal age at delivery, gestational age, age of child, child’s age squared, ethnic group, level of education attained by the mother, level of education attained by the father, family income per capita, caregiver of the child, parental emotional support.