SM (n = 9)

AM (n = 51)

Statistical analyses

Infants’ age (months)^a

9.0 (7.0 - 15.0)

12.0 (10.0 - 15.0)

p = 0.198

Maternal age (years)^b

22.0 ± 5.0

27.0 ± 6.0

p = 0.028

Maternal education (years)^b

9.0 ± 2.0

7.0 ± 3.0

p = 0.013

Socioeconomic class^c

p = 0.462

C

5

19

D

4

32

Primiparous^c

p = 0.032

Yes

7

19

No

2

32