Table 1.

Characteristics of included mother-infant dyads n = 27.

	n (%) 1
Maternal daily smoking	1 (4)
Maternal education > 4 years of higher education	13 (48)
Infant age in weeks, median (min–max)	18 (4–52)
Exclusively breastfed infants	20 (74)
The infant was breastfed before urine-sample was taken	23 (85)
Maternal age in years, median (min–max)	30 (20–39)

¹ Data are presented as number (n) and % unless indicated otherwise.