Table 1. Cohort characteristics.
| Variable | Accurately predicted birthweight category c (N = 368) | Inaccurately predicted birthweight category (N = 153) | P value |
|---|---|---|---|
| Maternal age (years) | 31.5 ± 5.4 | 31.0 ± 5.4 | 0.29 |
| Maternal race/ethnicity: | 0.20 | ||
| Non Hispanic white | 123 (38.4) | 45 (33.1) | |
| Non Hispanic black | 45 (14.1) | 30 (22.1) | |
| Hispanic | 76 (23.8) | 32 (23.5) | |
| Other | 76 (23.8) | 29 (21.3) | |
| Maternal BMI at delivery (kg/m2) | 0.40 | ||
| < 30 | 143 (38.9) | 69 (45.1) | |
| 30 – 39.9 | 151 (41.0) | 58 (37.9) | |
| ≥40 | 74 (20.1) | 26 (17.0) | |
| Type of diabetes: | 0.64 | ||
| A1 GDMb | 193 (52.5) | 86 (56.2) | |
| A2 GDM | 94 (25.5) | 40 (26.1) | |
| Type 2 DM | 39 (10.6) | 15 (9.8) | |
| Type 1 DM | 42 (11.4) | 12 (7.8) | |
| Gestational age at delivery (weeks) | 39.0 ± 1.0 | 39.0 ± 1.1 | 0.44 |
| Gestational age at ultrasound (weeks) | 37.1 ± 1.4 | 37.2 ± 1.4 | 0.24 |
| Time between last ultrasound and delivery (weeks) | 1.7 ± 1.3 | 1.5 ± 1.3 | 0.06 |
| Birthweight category at delivery: | < 0.001 | ||
| Small for gestational age | 3 (0.82) | 61 (39.9) | |
| Appropriate for gestational age | 316 (85.9) | 80 (52.3) | |
| Large for gestational age | 49 (13.3) | 12 (7.8) |
a
Numbers presented are either mean ± standard deviation or N(%).
b
GDM: gestational diabetes mellitus
c
‘Accurate’ and ‘inaccurate’ here refer to whether the predicted birthweight category (SGA, AGA, LGA) based on the ultrasound-estimated fetal weight was concordant with the actual birthweight category (SGA, AGA, LGA).