Table 1.
Characteristics of study participants at second trimester visit.
| Maternal blood lead levels (µg/dL) | ||||||
|---|---|---|---|---|---|---|
| Mean ± SDa |
Q1 <1.93 |
Q2 1.93–2.79 |
Q3 2.80–4.53 |
Q4 >4.53 |
P valuec |
|
| Characteristics | N=944 | N=236 | N=236 | N=236 | N=236 | |
| Maternal | ||||||
| Age (years) | 27.2 ± 5.5 | 26.6 ± 5.6 | 27.0 ± 5.2 | 27.4 ± 5.6 | 27.5 ± 5.5 | 0.008 |
| Height (cm) | 155.1 ± 5.5 | 155.3 ± 5.9 | 155.5 ± 5.6 | 154.7 ± 5.2 | 154.4 ± 5.4 | 0.003 |
| Body weight (kg) | 64.7 ± 4.1 | 65.0 ± 11.1 | 65.3 ± 10.9 | 63.7 ± 10.5 | 65.0 ± 11.9 | 0.29 |
| Body mass index (kg/m2) | 26.9 ± 4.2 | 26.9 ± 4.2 | 26.9 ± 4.1 | 26.6 ± 4.0 | 27.2 ± 4.5 | 0.84 |
| Hemoglobin levels (g/dL) | 12.9 ± 0.9 | 12.8 ± 0.8 | 12.9 ± 0.8 | 13.0 ± 0.9 | 13.0 ± 0.9 | 0.006 |
| Blood lead levels (µg/dL) | 3.7 ± 2.7 | 1.4 ± 0.3 | 2.4 ± 0.2 | 3.6 ± 0.5 | 7.3 ± 2.8 | - |
| Multiparous; n (%) | 591 (62.6) | 141 (14.9) | 151 (16.0) | 149 (15.8) | 150 (15.9) | 0.68 |
| Alcohol consumption; n (%) | 0.38 | |||||
| Yes | 78 (8.3) | 18 (7.6) | 22 (9.3) | 17 (7.2) | 21 (8.9) | |
| Socioeconomic status; n (%) | 0.009 | |||||
| Low | 484 (51.3) | 108 (11.5) | 121 (12.8) | 120 (12.7) | 135 (14.3) | |
| Medium | 354 (37.5) | 96 (10.2) | 86 (9.1) | 92 (9.7) | 80 (8.5) | |
| High | 106 (11.2) | 32 (3.4) | 29 (3.1) | 24 (2.5) | 21 (2.2) | |
| Household smoking exposured; n (%) | 0.84 | |||||
| Yes | 295 (31.3) | 64 (27.5) | 80 (34.0) | 81 (34.6) | 70 (29.8) | |
| Infant | ||||||
| Birthweight (g) | 3043 ± 482 | 3032 ± 497 | 3063 ± 439 | 3024 ± 510 | 3052 ± 481 | 0.82 |
| Gestational age (weeks) | 38.3 ± 1.9 | 38.1 ± 1.9 | 38.4 ± 1.8 | 38.2 ± 2.1 | 38.3 ± 1.8 | 0.13 |
| Birthweight-for-gestational age z- scoreb |
−0.5 ± 0.9 | −0.4 ± 0.8 | −0.5 ± 0.9 | −0.5± 1.0 | −0.5 ± 0.9 | 0.08 |
| Small-for-gestational age | 165 (17.5) | 33 (14.0) | 41 (17.4) | 43 (18.2) | 48 (20.3) | 0.01 |
| Infant sex; n (%) | 0.79 | |||||
| Males | 498 (52.7) | 119 (52.7) | 127 (53.8) | 124 (52.5) | 128 (54.2) | |
a
All values are shown as mean ± SD, unless otherwise noted.
b
Birthweight-for-gestational age z-score is adjusted for gestational age and calculated based on the Fenton growth charts.
c
P value corresponds to the univariate association between maternal blood lead levels and variables considered in the analysis.
d
Household smoking exposure was defined as the reported cases of indoor smoking exposure by the participant’s spouse and/or other household members. Data are missing for seven participants.