Infant assessments at birth and at 4 months
| At birth | At 4-month follow-up | Approximate median in US population at birth24 | |
|---|---|---|---|
| Number of infants | 86 | 59 | |
| Sex, n (%) | |||
| Female | 40 (46.5) | 26 (44.1) | |
| Male | 46 (53.5) | 33 (55.9) | |
| Infant weight, g | |||
| Median | 3346.8 | 6747.0 | 3200–3600 |
| Range | 470.0–4593.0 | 4763.0–8902.0 | |
| Infant size, n (%)* | |||
| Small | 7 (8.1) | 3 (5.1) | |
| Appropriate | 67 (77.9) | 48 (81.4) | |
| Large | 7 (8.1) | 6 (10.2) | |
| Missing | 5 (5.8) | 2 (3.4) | |
| Infant length, cm | |||
| Median | 50.8 | 63.5 | 49–50 |
| Range | 30.5–55.9 | 53.3–69.3 | |
| Infant head circumference, cm | |||
| Median | 34.3 | 41.9 | 34.8–35.8 |
| Range | 29.5–38.1 | 37.0–44.5 | |
| Gestational age at birth, weeks | |||
| Median | 39.0 | NA | |
| Range | 24.0–41.0 | NA | |
| Gestational age at birth, n (%)†‡ | |||
| Preterm | 8 (10.0) | NA | 9.9% |
| Term | 72 (90.0) | NA | |
*Infant size relative to gestational age at birth and age at 4 months (±4 weeks), respectively.
†Gestational age at birth calculated as ((280−(corrected estimated due date−outcome date))/7); EDD was used when corrected EDD was not available. Preterm births were defined as any baby born before the end of the 36th gestational week and term births were defined as those born after ≥37 weeks, 0 days gestation.25
‡Among singleton live births; excludes three twin pregnancies (6 live births) with outcomes at 24 weeks, 5 days; 36 weeks, 3 days; and 36 weeks, 5 days.
EDD, estimated due date; NA, not applicable.