Table 3.
Assessment of DDs without consideration of co-occurrence | Assessment of DDs in mutually exclusive categories. | ||||||
---|---|---|---|---|---|---|---|
Birth weight-gestational age group |
% Cases* | aRR (95% CI)† | PAF (95% CI)‡ | Birth weight-gestational age group |
% Cases | aRR (95% CI) | PAF (95% CI) |
CP | CP | ||||||
VLBW-Preterm§ | 32.7 | 43.5 (24.4, 77.6) | 32.0 (20.3, 46.2) | VLBW-Preterm | 32.7 | 43.5 (24.4, 77.6) | 32.0 (20.3, 46.2) |
MLBW-Preterm | 20.7 | 10.1 (5.0, 20.7) | 18.7 (8.7, 33.6) | MLBW-Preterm | 20.7 | 10.1 (5.0, 20.7) | 18.7 (8.7, 33.6) |
MLBW-Term | 2.9 | 1.7 (0.7, 4.4) | 1.2 (0.0, 5.9) | MLBW-Term | 2.9 | 1.7 (0.7, 4.4) | 1.2 (0.0, 5.9) |
NBW-Preterm | 5.4 | 2.2 (1.04, 4.6) | 2.9 (0.0, 8.8) | NBW-Preterm | 5.4 | 2.2 (1.04, 4.6) | 2.9 (0.0, 8.8) |
NBW-Term | 38.3 | 1.0 | 0.0 | NBW-Term | 38.3 | 1.0 | 0.0 |
Summary PAF | — | — | 54.8 (38.3, 68.9) | Summary PAF | — | — | 54.8 (38.3, 68.9) |
ASD | ASD (no CP) | ||||||
VLBW-Preterm | 4.2 | 3.7 (1.8, 7.7) | 3.1 (0.7, 8.8) | VLBW-Preterm | 3.9 | 3.6 (1.6, 7.9) | 2.8 (0.5, 8.8) |
MLBW-Preterm | 6.8 | 1.9 (1.3, 2.7) | 3.1 (0.8, 6.5) | MLBW-Preterm | 6.7 | 1.9 (1.3, 2.7) | 3.1 (0.8, 6.5) |
MLBW-Term | 2.7 | 1.2 (0.6, 2.1) | 0.4 (0.0, 3.0) | MLBW-Term | 2.7 | 1.2 (0.6, 2.2) | 0.4 (0.0, 3.0) |
NBW-Preterm | 10.7 | 2.0 (1.3, 3.0) | 5.3 (1.3, 11.2) | NBW-Preterm | 10.6 | 2.0 (1.3, 3.0) | 5.3 (1.2, 11.2) |
NBW-Term | 75.7 | 1.0 | 0.0 | NBW-Term | 76.1 | 1.0 | 0.0 |
Summary PAF | — | — | 11.9 (5.6, 19.4) | Summary PAF | — | — | 11.6 (5.3, 19.2) |
ID | ID (no CP, ASD) | ||||||
VLBW-Preterm | 6.6 | 5.1 (2.6, 10.0) | 5.3 (1.7, 13.0) | VLBW-Preterm | 3.3 | 2.6 (1.1, 6.1) | 2.0 (0.0, 6.7) |
MLBW-Preterm | 9.6 | 2.7 (1.8, 4.2) | 6.1 (2.5, 11.3) | MLBW-Preterm | 8.9 | 2.4 (1.4, 4.2) | 5.2 (1.0, 12.2) |
MLBW-Term | 4.6 | 1.7 (0.9, 2.9) | 1.8 (0.0, 5.7) | MLBW-Term | 5.0 | 1.7 (0.9, 3.1) | 2.0 (0.0, 6.6) |
NBW-Preterm | 10.0 | 2.2 (1.5, 3.2) | 5.4 (1.9, 10.1) | NBW-Preterm | 8.8 | 1.9 (1.2, 3.0) | 4.0 (0.4, 9.5) |
NBW-Term | 69.2 | 1.0 | 0.0 | NBW-Term | 74.0 | 1.0 | 0.0 |
Summary PAF | — | — | 18.6 (10.6, 27.8) | Summary PAF | — | — | 13.2 (4.9, 23.4) |
BCD | BCD (no CP, ASD, ID) | ||||||
VLBW-Preterm | 1.8 | 1.1 (0.6, 2.0) | 0.2 (0.0, 1.8) | VLBW-Preterm | 1.8 | 1.2 (0.6, 2.6) | 0.3 (0.0, 2.6) |
MLBW-Preterm | 6.3 | 1.5 (1.1, 2.1) | 2.1 (0.1, 4.8) | MLBW-Preterm | 6.5 | 1.6 (1.1, 2.2) | 2.3 (0.1, 5.5) |
MLBW-Term | 3.4 | 1.0 (0.7, 1.6) | 0.1 (0.0, 2.2) | MLBW-Term | 3.8 | 1.1 (0.7, 1.8) | 0.4 (0.0, 3.1) |
NBW-Preterm | 7.4 | 1.4 (0.99, 1.9) | 1.9 (0.0, 5.0) | NBW-Preterm | 7.2 | 1.4 (0.9, 2.0) | 1.9 (0.0, 5.8) |
NBW-Term | 81.2 | 1.0 | 0.0 | NBW-Term | 80.8 | 1.0 | 0.0 |
Summary PAF | — | — | 4.3 (0.3, 9.0) | Summary PAF | — | — | 5.0 (0.3, 10.5) |
ADHD | ADHD (no CP, ASD, ID, BCD) | ||||||
VLBW-Preterm | 2.2 | 1.6 (1.2, 2.3) | 0.9 (0.2, 1.9) | VLBW-Preterm | 1.6 | 1.3 (0.9, 2.0) | 0.4 (0.0, 1.3) |
MLBW-Preterm | 5.0 | 1.3 (1.04, 1.5) | 1.1 (0.1, 2.3) | MLBW-Preterm | 4.7 | 1.3 (0.99, 1.6) | 1.0 (0.0, 2.5) |
MLBW-Term | 2.8 | 1.0 (0.8, 1.3) | 0.0 (0.0, 1.0) | MLBW-Term | 2.6 | 0.9 (0.7, 1.3) | 0.0 (0.0, 1.1) |
NBW-Preterm | 8.2 | 1.5 (1.2, 1.8) | 2.5 (1.0, 4.5) | NBW-Preterm | 8.1 | 1.5 (1.2, 1.9) | 2.6 (0.6, 5.1) |
NBW-Term | 81.8 | 1.0 | 0.0 | NBW-Term | 83.0 | 1.0 | 0.0 |
Summary PAF | — | — | 4.4 (2.0, 7.1) | Summary PAF | — | — | 3.8 (1.0, 7.06) |
LD | LD (no CP, ASD, ID, BCD, ADHD) | ||||||
VLBW-Preterm | 3.7 | 2.8 (2.1, 3.7) | 2.4 (1.3, 3.8) | VLBW-Preterm | 4.2 | 3.3 (2.0, 5.4) | 3.0 (1.2, 5.9) |
MLBW-Preterm | 7.8 | 2.0 (1.7, 2.4) | 3.9 (2.4, 5.7) | MLBW-Preterm | 7.1 | 2.0 (1.3, 2.8) | 3.5 (1.0, 7.0) |
MLBW-Term | 3.6 | 1.2 (0.9, 1.6) | 0.7 (0.0, 2.0) | MLBW-Term | 4.2 | 1.3 (0.8, 2.0) | 1.0 (0.0, 3.8) |
NBW-Preterm | 8.3 | 1.6 (1.4, 2.0) | 3.2 (1.6, 5.2) | NBW-Preterm | 6.5 | 1.4 (1.00, 1.9) | 1.7 (0.0, 4.4) |
NBW-Term | 76.5 | 1.0 | 0.0 | NBW-Term | 77.9 | 1.0 | 0.0 |
Summary PAF | — | — | 10.2 (7.3, 13.4) | Summary PAF | — | — | 9.1 (4.4, 14.5) |
Other developmental delay | Other developmental delay (no CP, ASD, ID, BCD, ADHD, LD) | ||||||
VLBW-Preterm | 6.8 | 5.5 (4.1, 7.4) | 5.6 (3.6, 8.2) | VLBW-Preterm | 8.8 | 9.8 (5.0, 19.2) | 7.9 (3.6, 15.4) |
MLBW-Preterm | 10.1 | 2.8 (2.2, 3.6) | 6.5 (4.0, 9.6) | MLBW-Preterm | 9.0 | 2.7 (1.4, 5.1) | 5.6 (1.0, 14.0) |
MLBW-Term | 3.5 | 1.4 (0.9, 2.0) | 1.0 (0.0, 2.9) | MLBW-Term | 2.6 | 1.1 (0.4, 3.5) | 0.3 (0.0, 6.2) |
NBW-Preterm | 10.7 | 2.3 (1.8, 3.0) | 6.1 (3.2, 9.8) | NBW-Preterm | 12.9 | 3.0 (1.6, 5.6) | 8.6 (2.2, 19.5) |
NBW-Term | 68.8 | 1.0 | 0.0 | NBW-Term | 66.8 | 1.0 | 0.0 |
Summary PAF | — | — | 19.1 (14.2, 24.2) | Summary PAF | — | — | 22.4 (10.9, 36.0) |
% cases: (number of exposed cases/number of all cases) × 100, weighted.
aRR: Relative risk, adjusted for child age, sex, race/ethnicity, maternal education, and maternal age. Findings in boldface indicate 95% confidence interval excludes 1.0.
PAF estimate or lower bound of PAF CI reported as 0.0 for all instances in which the value was less than 0.0. Findings in boldface indicate 95% confidence interval excludes 0.0.
All VLBW births were preterm. We excluded from our study sample a small number of children classified as both VLBW and Term. These data were considered implausible as birth weights less than 1500 g are below the third percentile of what is expected for births at 37 weeks’ gestation or higher based on a US national reference for both males and females.