Table 3.
Associations between maternal haemoglobin concentrations at enrolment and pregnancy and infant outcomes
| Model 1b | Model 2c | |||||
|---|---|---|---|---|---|---|
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| Variablesa | n | β (SE) or RR (95% CI) | P-value | n | β (SE) or RR (95%CI) | P-value |
| Pregnancy outcomes | ||||||
| Birth weight, g | 252 | 37.4 (18.2) | 0.04 | 243 | 35.0 (18.2) | 0.05 |
| Low birth weight (<2500 g), n (%) | 252 | 0.91 (0.77, 1.07) | 0.27 | 243 | 0.87 (0.73, 1.04) | 0.13 |
| Gestational age at birth, weeks | 258 | 0.27 (0.08) | 0.001 | 249 | 0.28 (0.08) | 0.001 |
| Preterm (<37 weeks), n (%) | 258 | 0.76 (0.67, 0.87) | <0.0001 | 249 | 0.76 (0.66, 0.86) | <0.0001 |
| Preterm and low birth weight, n (%) | 252 | 0.90 (0.68, 1.20) | 0.48 | 243 | 0.86 (0.64, 1.15) | 0.30 |
| Small for gestational aged, n (%) | 251 | 0.98 (0.88, 1.09) | 0.72 | 242 | 0.98 (0.88, 1.09) | 0.67 |
| Infant outcomes | ||||||
| Haemoglobin, g/dl | 73 | 0.14 (0.14) | 0.33 | 69 | 0.22 (0.14) | 0.13 |
| Anaemia (<11.0 g/dl), n (%) | 73 | 1.02 (0.86, 1.22) | 0.81 | 69 | 0.94 (0.78, 1.13) | 0.52 |
| Length, cm | 227 | 0.14 (0.12) | 0.27 | 218 | 0.10 (0.12) | 0.42 |
| Length-for-age z-score (LAZ) | 225 | 0.04 (0.06) | 0.47 | 216 | 0.01 (0.06) | 0.81 |
| LAZ < −2 | 225 | 0.98 (0.87, 1.11) | 0.77 | 216 | 1.01 (0.90, 1.14) | 0.84 |
| Weight-for-age z-score (WAZ) | 251 | 0.08 (0.04) | 0.05 | 242 | 0.08 (0.04) | 0.06 |
| WAZ < −2 | 251 | 0.89 (0.74, 1.07) | 0.22 | 242 | 0.82 (0.67, 1.01) | 0.06 |
| Weight-for-length z-score (WLZ) | 185 | 0.07 (0.08) | 0.38 | 178 | 0.07 (0.08) | 0.40 |
| WLZ < −2 | 185 | 1.02 (0.83, 1.25) | 0.87 | 178 | 1.03 (0.85, 1.25) | 0.78 |
| BMI z-score (BMIZ) | 224 | 0.09 (0.07) | 0.16 | 215 | 0.09 (0.07) | 0.19 |
| BMIZ < −2 | 224 | 0.90 (0.76, 1.05) | 0.18 | 215 | 0.88 (0.74, 1.05) | 0.16 |
| Ponderal Index, g/cm3 | 226 | 0.0002 (0.0002) | 0.46 | 217 | 0.0002 (0.0002) | 0.44 |
| Head circumference, cm | 227 | 0.08 (0.07) | 0.28 | 218 | 0.06 (0.07) | 0.38 |
| Chest circumference, cm | 227 | 0.14 (0.09) | 0.11 | 218 | 0.14 (0.09) | 0.11 |
| Waist circumference, cm | 227 | 0.18 (0.12) | 0.13 | 218 | 0.19 (0.12) | 0.11 |
| Hip circumference, cm | 227 | −0.06 (0.17) | 0.72 | 218 | −0.04 (0.17) | 0.82 |
| Mid-upper arm circumference, cm | 225 | 0.36 (0.14) | 0.008 | 216 | 0.36 (0.13) | 0.006 |
| Biceps skinfold, mm | 226 | 0.04 (0.04) | 0.32 | 217 | 0.05 (0.04) | 0.26 |
| Triceps skinfold, mm | 226 | 0.05 (0.06) | 0.45 | 217 | 0.06 (0.07) | 0.35 |
a
Hb, g/dl enrolment (≤14 weeks gestation); beta (SE) is reported for continuous pregnancy outcomes; RR (95%CI) is reported for binary pregnancy outcomes
b
Models adjusted for gestational age of sample and vitamin B12 intervention
c
Models adjusted for gestational age of sample, vitamin B12 intervention, maternal BMI, standard of living index (SLI) >28, educational level, and ln(CRP)
d
Small for gestational age (SGA) was defined as birth weight < 10th percentile of the gestational age, using INTERGROWTH reference [17]