Table 1. Demographic Characteristics of Mothers.
| Characteristic | No (%) | P value | ||
|---|---|---|---|---|
| Total | Low SES group | High SES group | ||
| Total participants | 144 | 72 (50.0) | 72 (50.0) | NA |
| Sex of fetus | ||||
| Female | 69 (47.9) | 35 (48.6) | 34 (47.2) | .87 |
| Male | 75 (52.1) | 37 (51.4) | 38 (52.8) | |
| No. of scans | ||||
| 1 | 104 (72.2) | 55 (76.4) | 49 (68.1) | .31 |
| 2 | 40 (27.8) | 17 (23.6) | 23 (31.9) | |
| MRI scans | 184 | 89 (48.4) | 95 (51.6) | NA |
| Time point 1 | 85 (46.2) | 44 (49.4) | 41 (43.2) | .39 |
| Time point 2 | 99 (53.8) | 45 (50.6) | 54 (56.8) | |
| GA, median (range), wk | ||||
| At MRI overall | 33.6 (29.3 to 36.1) | 33.0 (29.3 to 35.9) | 33.7 (29.3 to 36.4) | .50 |
| At MRI time point 1 | 29.1 (27.7 to 31.1) | 29.2 (27.6 to 31.1) | 29.1 (27.6 to 30.9) | .76 |
| At MRI time point 2 | 35.9 (34.7 to 37.0) | 35.7 (34.6 to 37.0) | 36.1 (34.7 to 37.0) | .76 |
| At birtha | 39.6 (38.7 to 40.3) | 39.3 (38.4 to 40.0) | 39.7 (38.9-40.5) | .04 |
| Maternal age, median (IQR), yb | 32.5 (27.0 to 36.1) | 26.6 (22.2 to 32.5) | 34.9 (32.4 to 38.2) | <.001 |
| Maternal parity c | ||||
| Primiparous | 67 (46.5) | 27 (37.5) | 40 (55.6) | .01 |
| Multiparous | 68 (47.2) | 42 (58.3) | 26 (36.1) | |
| Child characteristics at birth, median (IQR), z score | ||||
| Weight, kgd | 0.07 (−0.60 to 0.63) | −0.12 (−0.68 to 0.57) | 0.28 (−0.42 to 0.76) | .10 |
| Length, cme | 0.04 (−0.75 to 0.60) | −0.21 (−0.99 to 0.28) | 0.12 (−0.37 to 0.71) | .15 |
| Head circumference, cmf | −0.26 (−0.59 to 0.75) | −0.26 (−0.93 to 0.42) | 0.08 (−0.59 to 0.75) | .15 |
| Mothers’ race/ethnicity | ||||
| White | 68 (47.2) | 16 (22.2) | 52 (72.2) | <.001 |
| Black | 45 (31.3) | 40 (55.6) | 5 (6.9) | |
| Hispanic or Latino | 16 (11.1) | 7 (9.7) | 9 (12.5) | |
| Asian or Pacific Islander | 6 (4.2) | 3 (4.2) | 3 (4.2) | |
| Other or unknown | 9 (6.3) | 6 (8.3) | 3 (4.2) | |
Abbreviations: GA, gestational age; IQR, interquartile range; MRI, magnetic resonance imaging; NA, not applicable; SES, socioeconomic status.
a
Based on 134 participants.
b
Based on 134 participants.
c
Based on 135 participants.
d
Based on 122 participants.
e
Based on 78 participants.
f
Based on 78 participants.