Table 1.

Outcomes, exposure, and confounders included in the statistical models.

Outcome	Exposure	Confounders
Child gut microbiota at birth, 6 m, 12 m and 24 m	Age
	Maternal gut microbiota at gestational week 26–28	Furry pet, parity
	Mode of delivery	Maternal BMI, parity, gestational age, birth weight
	Parity	Maternal age
	Gestational age	Maternal education level*
	Birth weight	Maternal BMI, maternal education level, parity, gestational age*
Child gut microbiota at birth, 6 m, 12 m and 24 m	Prenatal antibiotic treatment (maternal use of antibiotics during pregnancy)	Maternal age, maternal education, parity, maternal BMI*
Child gut microbiota at 24 m	Antibiotic treatment	Maternal age, maternal education level, sex, gestational age, mode of delivery, parity, birth weight
Child gut microbiota at birth, 6 m, 12 m and 24 m	Furry pet in the household at baseline	Maternal age, maternal education level

BMI Body Mass Index, m month.

*Maternal smoking during pregnancy was identified as a potential confounder. However, in our maternal cohort no women reported smoking whilst pregnant, and this variable is therefore not included in the model.