Table 1.
GRAPHS participant characteristics (n=1,196)
| All Children (n=1,196) | Females (n=597) | Males (n=599) | |
|---|---|---|---|
| Gestational age at delivery, weeks -- median (IQR) † | 39 (39, 40) | 39 (39, 40) | 39 (39, 40) |
| Maternal age, years -- median (IQR) | 27 (22.4, 33.6) | 27.5 (22.8, 33.9) | 26.7 (21.8, 33.6) |
| Maternal body mass index, kg/m2 – median (IQR) | 22.9 (21.1, 25) | 22.7 (20.9, 25) | 23 (21.3, 25) |
| Parity, no. (%) | |||
| 0 | 197 (17) | 89 (15) | 108 (18) |
| 1 | 208 (17) | 108 (19) | 100 (17) |
| 2 | 209 (18) | 111 (19) | 98 (16) |
| 3 | 168 (14) | 76 (13) | 92 (15) |
| ≥4 | 414 (35) | 213 (36) | 201 (34) |
| Asset index – median (IQR) | −0.42 (−1.3, 0.8) | −0.43 (−1.3, 0.7) | −0.41 (−1.3, 0.8) |
| Prenatal CO average, ppm – median (IQR) ± | 1.07 (0.64, 1.67) | 1.03 (0.64, 1.59) | 1.05 (0.64, 1.64) |
| Postnatal CO average, ppm – median (IQR) ± | 0.52 (0.24, 1.02) | 0.54 (0.25, 1.03) | 0.52 (0.23, 1.00) |
| n-miss | 232 | 128 | 104 |
| Ethnicity – no. (%) | |||
| 1 | 203 (17) | 109 (18) | 94 (16) |
| 2 | 155 (13) | 72 (12) | 83 (14) |
| 3 | 786 (66) | 393 (66) | 393 (66) |
| 4 | 52 (4) | 23 (4) | 29 (5) |
| Outcomes | |||
| Birth weight, kilograms – median (IQR) | 2.94 (2.7, 3.2) | 2.9 (2.6, 3.1) | 3 (2.7, 3.2) |
| Any pneumonia, yes – no. (%) | 303 (25) | 134 (22) | 169 (28) |
| Any severe pneumonia, yes – no. (%) | 111 (9) | 53 (9) | 59 (10) |
Abbreviations: CO, carbon monoxide; IQR, interquartile range, kg/m2, kilogram per meter-squared; ppm, parts per million
†
Gestational age at delivery, established by ultrasound-determined gestational dating
±
Due to QA/QC, 232 children did not have valid, postnatal (infant) CO data