Table 2.
Body composition and brain metrics at term equivalent age (n=62).
| Characteristic1 | Median (Range) or Mean ± Standard Deviation |
|---|---|
| Postmenstrual age (weeks) | 39.4 (35.9, 42.1) |
| Anthropometrics | |
| Weight at term (g) | 2982 ± 503 |
| Weight Z-score at term2 | −0.6 (−3.2, 0.7) |
| Δ weight Z-score (birth to term)2 | −0.5 (−3.1, 1.8) |
| Length at term (cm) | 47.8 ± 2.6 |
| Length Z-score at term2 | −0.8 (−4.3, 0.7) |
| Δ length Z-score (birth to term)2 | −0.9 (−2.0, 1.4) |
| Head circumference at term (cm)3 | 34.0 ± 1.5 |
| Head circumference Z-score at term3 | −0.1 (−2.0, 1.9) |
| Δ HC Z-score (birth to term)2 | 0.4 (−1.6, 3.1) |
| Body mass index Z-score at term2 | 0.2 (−1.8, 1.5) |
| Δ BMI Z-score (birth to term)2 | −0.02 (−2.8, 2.8) |
| Body composition | |
| Fat-free mass (g) | 2442 ± 384 |
| Fat-free mass index (kg/m2) | 10.7 ± 1.0 |
| Fat mass (g) | 539 ± 207 |
| Fat mass index (kg/m2) | 2.3 ± 0.8 |
| Body fat percentage | 17.7 ± 5.3 |
| Brain metrics | |
| Bifrontal diameter (mm) | 69.4 ± 4.7 |
| Biparietal diameter (mm) | 80.4 ± 5.3 |
| Transverse cerebellar diameter (mm) | 51.0 ± 2.8 |
1
N(%) for categorical data, mean ± standard deviation for normally distributed data, or median (minimum, maximum) for skewed data (postmenstrual age, anthropometric Z-scores).
2
1 infant was missing weight, length, and body mass index Z-score at term equivalent age due to being measured at 42 weeks, beyond the range covered by the Olsen growth charts.
3
2 infants were missing head circumference data at term equivalent age.