Table 1.
Description of sociodemographic and environmental, infant lung function, and psychological adversity variables
| ILF test at 6‐10 weeks (N = 762) | ILF followed up at 12 months (N = 485) a | P b | |
|---|---|---|---|
| Child's male sex | 391 (51%) | 238 (49%) | .440 |
| Maternal smoking (cotinine) | |||
| Passive | 149/486 (31%) | 94/310 (30%) | .920 |
| Active | 237/486 (49%) | 162/310 (52%) | .336 |
| Gestation age (GA) | |||
| Large (weight >90th %centile GA) | 35 (5%) | 23 (5%) | .903 |
| Normal (GA not large or small) | 531 (70%) | 334 (69%) | .759 |
| Small weight <10th %centile GA | 196 (26%) | 128 (26%) | .792 |
| Prematurity (delivery <37 weeks) | 94 (12%) | 62 (13%) | .815 |
| Birth season | |||
| Autumn | 188 (25%) | 137 (28%) | .160 |
| Spring | 171 (22%) | 98 20%) | .349 |
| Summer | 216 (28%) | 150 (31%) | .329 |
| Winter | 187 (24%) | 100 (21%) | .108 |
| Abnormal delivery mode | |||
| Assisted breech | 4/759 (1%) | 2 (<1%) | .775 |
| Elective CS | 54/759 (7%) | 38 (8%) | .635 |
| Emergency CS | 97/759 (13%) | 49 (10%) | .152 |
| Mother breastfeeds child | 670/759 (88%) | 427 (88%) | .901 |
| Socioeconomic status | |||
| High | 187 (25%) | 118 (24%) | .932 |
| Moderate‐high | 192 (25%) | 126 (26%) | .757 |
| Low‐moderate | 190 (25%) | 130 (27%) | .461 |
| Low | 193 (25%) | 111 (23%) | .327 |
| Black African ancestry of mother | 393 (52%) | 230 (47%) | .152 |
| Maternal alcohol use in pregnancy | 157/447 (35%) | 101/297 (34%) | .754 |
| Presence of benzene in household | 250/472 (53%) | 156/310 (50%) | .469 |
| Maternal age in years: mean (IQR) | 27 (6) | 27 (23‐31) | |
| Maternal respiratory illness | 36 (5%) | 25 (5%) | .731 |
| Maternal HIV | 146 (19%) | 92 (19%) | .933 |
| Maternal psychological adversity variables | |||
| Intimate partner violence | |||
| Prenatal, median (IQR) | 14.0 (12.0‐17.0) | 14 (12‐18) | .596 |
| Postnatal, median (IQR) | 12.0 (12.0‐16.0) | 12.0 (12.0‐16.0) | .594 |
| Prenatal posttraumatic stress disorders | |||
| Suspected | 94/688 (13.7%) | 62/436 (14.2%) | .813 |
| Definite | 92/688 (13.4%) | 53/436 (12.1%) | .526 |
| Postnatal posttraumatic stress disorders | |||
| Suspected | 5/99 (5.0%) | 4/66 (6.1) | .760 |
| Definite | 4/99 (4.0%) | 2/66 (3.0) | .736 |
| Depression scores | |||
| Prenatal, median IQR | 9.0 (6.0‐13.0) | 9.0 (6.0‐13.0) | .758 |
| Postnatal, median IQR | 8.0 (5.0‐11.0) | 8.0 (5.0‐11.0) | .771 |
| Infant lung function variables | |||
| Tidal volume (mL), median (Q1‐Q3) | 34.6 (30.8‐38.6) | 91.5 (82.6‐101.5) | <.001 |
| Ratio of time to peak tidal expiratory flow over total expiratory time, median (IQR) | 38.1 (29.6‐46.1) | 28.3 (22.6‐36.1) | <.001 |
| Respiratory rate (breaths per minutes), median (IQR) | 47.0 (40.5‐54.7) | 29 (25‐33) | <.001 |
| Functional respiratory capacity (mL), median (IQR) | 75.4 (66.1‐86.6) | 201.2 (171.0‐226.7) | <.001 |
| Respiratory system resistance (cmH2O·L·s−1), median (IQR) | 44.7 (37.2‐55.0) | NA | |
| Respiratory system compliance (cmH2O·mL−1) | 96.1 (73‐122) | NA | |
IQR, interquartile range; ILF, infant lung function; NA, not applicable; Q, quartile.
a
Includes only those with psychological data at both baseline and follow up.
b
Two sample comparison of proportions and means.