Table 1.
Sociodemographic and Clinical Characteristics of 774 Mother–Infant Pairs
| Variables | Total n (%) | Median (IQR) |
|---|---|---|
| Maternal characteristics | ||
| Median (IQR) age, years | … | 26 (22–31) |
| Age group | ||
| <20 years | 89 (11.5) | |
| 20–24 years | 253 (32.7) | |
| 25–29 years | 209 (27.0) | |
| ≥30 years | 223 (28.8) | |
| Education | ||
| Primary | 58 (7.5) | |
| Some secondary | 413 (53.4) | |
| Completed secondary | 256 (33.1) | |
| Some tertiary | 47 (6.1) | |
| HIV-positive status | 166 (21.4) | |
| Maternal smoking in pregnancy | 182 (23.5) | |
| Infant characteristics | ||
| Birth weight, g | 3100 (2750, 3420) | |
| Weight-for-age z scorea | −0.39 (−1.15, 0.33) | |
| Height-for-age z scorea | −0.83 (−1.75, −0.01) | |
| Female | 366 (47.3) | |
| Gestation delivery, weeks | 39 (38, 40) | |
| Prematurity (<37 weeks) | 98 (12.7) | |
| Breastfeeding initiated | 718 (92.8) | |
| HIV-positive status | 2 (0.3) | |
| Season of birth | ||
| Summer (December–February) | 220 (28.4) | |
| Autumn (March–May) | 195 (25.2) | |
| Winter (June–August) | 189 (24.4) | |
| Spring (September– November) | 170 (22.0) | |
| Household characteristics | ||
| Socioeconomic statusb | ||
| Lowest | 190 (23.8) | |
| Moderate low | 190 (25.2) | |
| Moderate high | 195 (25.6) | |
| High | 193 (25.4) |
Percentages refer to within-characteristic column totals among participants within each clinic and in entire study. Percentages may not total 100% because within-column percentages were rounded to the nearest integer. Column totals vary across different characteristics due to missing values for some participants.
Abbreviations: HIV, human immunodeficiency virus; IQR, interquartile range.
aWe derived z scores from World Health Organization child growth standards at birth and at every follow-up visit; we used the median of all the weight-for-age z scores for each child to summarize nutrition status over the duration of follow-up.
bSocioeconomic status comprised a comprehensive composite of asset ownership, household income, employment, and education.