Table 2.
Pregnancy and Infant Characteristics of Mothers Whose Children Contributed Delivery and Follow-up Data (n = 806)a
| No. (%) of Participants | |||
|---|---|---|---|
| 4400 IU/d of Vitamin D (n = 405) | 400 IU/d of Vitamin D (n = 401) | Mean Difference Between Groups (95% CI) | |
| Maternal Characteristics | |||
| 25-Hydroxyvitamin D levels, ng/mL | |||
| Baseline | |||
| Women, No. | 402 | 399 | |
| Mean (95% CI) | 23.3 (22.3 to 24.4) | 22.6 (21.6 to 23.6) | 0.7 (−0.7 to 2.2) |
| Third trimester | |||
| Women, No. | 383 | 387 | |
| Mean (95% CI) | 39.3 (37.8 to 40.9) | 26.8 (25.7–27.9) | 12.4 (10.7–14.4) |
| Cord bloodb | |||
| Newborn, No. | 303 | 317 | |
| Mean (95% CI) | 28.0 (26.6 to 29.4) | 19.2 (18.1 to 20.3) | 8.8 (7.1 to 10.6) |
| Time in study, mean (95% CI), dc | 173.5 (171.2 to 175.8) | 174.4 (172.0 to 176.8) | −0.9 (−4.3 to 2.4) |
| Medication adherence (MEMS), % | |||
| Women, No. | 402 | 400 | |
| Mean (95% CI) | 70 (67.3 to 72.7) | 71.3 (68.6 to 74.0) | −1.3 (−5.2 to 2.5) |
| Rate Difference (95% CI)d | |||
| Mode of delivery | |||
| Cesarean | 123 (31) | 116 (29) | 2 (−8 to 5) |
| Vaginal | 279 (69) | 285 (71) | −2 (−10 to 6) |
| Delivery <37 wk | 40 (10) | 31 (8) | 2 (−2 to 6) |
| Infant Characteristics in First Year | |||
| Birth weight, g | |||
| Infants, No. | 402 | 401 | |
| Mean (95% CI) | 3267.9 (3214.9 to 3321.1) | 3282.5 (3224.9 to 3340.1) | −14.5 (−92.8 to 63.7) |
| Birth length, cm | |||
| Infants, No. | 401 | 399 | |
| Mean (95% CI) | 50.6 (50.3 to 50.9) | 50.7 (50.3 to 51.0) | −0.1 (−0.5 to 0.4) |
| Head circumference, cm | |||
| Infants, No. | 398 | 398 | |
| Mean (95% CI) | 34 (33.8 to 34.2) | 34 (33.8 to 34.2) | 0 (−0.3 to 0.3) |
| Rate Difference (95% CI)d | |||
| Sex | |||
| Boy | 200 (49) | 220 (55) | −5 (−13 to 2) |
| Girl | 205 (51) | 181 (45) | 5 (−2 to 13) |
| Race/ethnicity | |||
| Black | 199 (49) | 191 (48) | 2 (−6 to 9) |
| White Hispanic | 53 (13) | 51 (13) | 0 (−5 to 5) |
| White, non-Hispanic | 82 (20) | 79 (20) | 1 (−5 to 6) |
| Other | 71 (18) | 80 (20) | −2 (−8 to 3) |
| First-year reports | |||
| Breastfeeding | 213 (55) | 206 (53) | 2 (−6 to 9) |
| Formula use | 338 (87) | 330 (85) | 2 (−3 to 7) |
| 400 IU Vitamin D drops/d | 179 (46) | 169 (43) | 2 (−5 to 10) |
| Use of multivitamin drops | 74 (19) | 87 (22) | −3 (−9 to 3) |
Abbreviation: MEMS, medication event monitoring system.
SI conversion factor: To convert 25-hydroxyvitamin from ng/mL to nmol/L, multiply by 2.496.
a
Numbers and percentages reflect some missing data and may not sum due to rounding.
b
Measured by liquid chromatography coupled to tandem mass spectrometry.
c
Enrollment to delivery.
d
Rate differences are expressed as difference in percentages.