Table 4. Comparison of model performance for the three different methods in detecting SGA and LGA with morbidity for birthweight at 37–42 weeks of gestation in the Consortium on Safe Labor study (N = 102,012).
| Classification | n | Composite neonatal morbidity % | PPV | NPV | Sensitivity | Specificity | Odds ratio (95% CI) | c-statistic (95% CI) |
|---|---|---|---|---|---|---|---|---|
| LGA > 90th | ||||||||
| Duryea | 9,895 | 9.7 | 7.7 | 95.1 | 14.5 | 90.6 | 1.62 (1.50–1.75) | 0.53 (0.52–0.53) |
| Gardosi | 7,814 | 7.7 | 8.5 | 95.1 | 12.6 | 92.6 | 1.80 (1.65–1.96) | 0.53 (0.52–0.53) |
| Heteroscedastic | 10,497 | 10.3 | 7.7 | 95.1 | 15.3 | 90.0 | 1.63 (1.50–1.76) | 0.53 (0.52–0.53) |
| Quantile | 10,211 | 10.0 | 8.0 | 95.1 | 15.4 | 90.3 | 1.69 (1.56–1.83) | 0.53 (0.52–0.53) |
| SGA < 10th | ||||||||
| Duryea | 9,385 | 9.2 | 6.5 | 96.3 | 15.2 | 91.04 | 1.82 (1.66–1.99) | 0.54 (0.53–0.54) |
| Gardosi | 7,294 | 7.2 | 7.2 | 96.3 | 13.2 | 93.09 | 2.05 (1.86–2.25) | 0.53 (0.52–0.53) |
| Heteroscedastic | 10,538 | 10.3 | 5.6 | 96.3 | 14.9 | 89.85 | 1.55 (1.41–1.69) | 0.52 (0.52–0.52) |
| Quantile | 10,201 | 10.0 | 5.9 | 96.3 | 15.0 | 90.20 | 1.63 (1.49–1.78 | 0.53 (0.52–0.53) |
Note: In the Consortium on Safe Labor Study, birthweight was predicted by using models’ coefficients from the NICHD Fetal Growth Studies. Large- and small-for-gestational-age (LGA and SGA, respectively) were defined according to different models, then calculated the positive predictive value (PPV), negative predictive value (NPV), sensitivity, specificity, odds ratio and c-statistic using neonatal morbidity as the outcome. Neonatal morbidities were selected specifically for SGA or LGA based on increased risks associated with these and included: metabolic acidosis (pH <7.1 and base deficit >12mmol/L), NICU stay greater than three days, pneumonia, respiratory distress syndrome, persistent pulmonary hypertension, seizures, hyperbilirubinemia requiring exchange transfusion, intrapartum aspiration (meconium, amniotic fluid, blood), neonatal death, mechanical ventilation at term, necrotizing enterocolitis, hypoglycemia, hypoxic ischemic encephalopathy, periventricular leukomalacia (SGA only), sepsis based on blood culture (SGA only), bronchopulmonary dysplasia/chronic lung disease (SGA only), retinopathy of prematurity (SGA only), and birth injury (LGA only) [22–26].