Table 3.
Age of motor milestone achievement | Estimate | 95% CI | P value |
All infants (n=425) | |||
Rolling over (ref=older than 4 months) | |||
4 months or younger | −0.19 | −0.40 to 0.008 | 0.06 |
Sitting up (ref=older than 6 months) | |||
5 months or younger | 0.19 | −0.06 to 0.43 | 0.13 |
5–6 months | 0.22 | −0.03 to 0.48 | 0.09 |
Crawling (ref=9 months and older) | |||
6 months or younger | −0.34 | −0.59 to −0.09 | 0.008 |
7–8 months | 0.01 | −0.20 to 0.21 | 0.94 |
Walking (ref=older than 12 months) | |||
11 months and younger | −0.17 | −0.39 to 0.06 | 0.14 |
12 months | 0.13 | −0.10 to 0.37 | 0.27 |
Male infants only (n=208) | |||
Rolling over (ref=older than 4 months) | |||
4 months or younger | −0.29 | −0.60 to 0.02 | 0.06 |
Sitting up (ref=older than 6 months) | |||
5 months or younger | 0.18 | −0.17 to 0.54 | 0.31 |
5–6 months | 0.27 | −0.10 to 0.64 | 0.15 |
Crawling (ref=9 months and older) | |||
6 months or younger | −0.46 | −0.83 to −0.10 | 0.01 |
7–8 months | −0.06 | −0.37 to 0.25 | 0.91 |
Walking (ref=older than 12 months) | |||
11 months and younger | −0.09 | −0.44 to 0.26 | 0.63 |
12 months | 0.08 | −0.28 to 0.44 | 0.66 |
Female infants only (n=217) | |||
Rolling over (ref=older than 4 months) | |||
4 months or younger | −0.12 | −0.40 to 0.16 | 0.39 |
Sitting up (ref=older than 6 months) | |||
5 months or younger | 0.18 | −0.16 to 0.52 | 0.30 |
5–6 months | 0.16 | −0.20 to 0.53 | 0.37 |
Crawling (ref=9 months and older) | |||
6 months or younger | −0.27 | −0.63 to 0.08 | 0.13 |
7–8 months | 0.05 | −0.24 to 0.33 | 0.75 |
Walking (ref=older than 12 months) | |||
11 months and younger | −0.25 | −0.56 to 0.05 | 0.10 |
12 months | 0.20 | −0.14 to 0.54 | 0.24 |
*Adjusted for maternal prepregnancy body mass index, age and education; household income; infant race, gender, birth weight for gestational age z score and breast feeding.