Table 1.
Characteristics of Study Participants from the Consortium on Safe Labor, 2002–2008.
| Characteristics | Fetal growth | Term births | ||||||
|---|---|---|---|---|---|---|---|---|
|
| ||||||||
| SGA (N=22,239) |
AGA (N=176,064) |
LBW (N=4,322) |
Not tLBW (N=190,850) |
|||||
| Infant sex | N | % | N | % | N | % | N | % |
| Female | 10,880 | 48.9 | 86,064 | 48.9 | 2,606 | 60.3 | 93,229 | 48.9 |
| Male | 11,359 | 51.1 | 90,000 | 51.1 | 1,716 | 39.7 | 97,621 | 51.2 |
| Race/ethnicity | ||||||||
| NH-White | 8,612 | 38.7 | 87,990 | 50.0 | 1,597 | 37.0 | 97,238 | 51.0 |
| NH-Black | 7,299 | 32.8 | 38,618 | 21.9 | 1,538 | 35.6 | 39,880 | 20.9 |
| Hispanic | 3,724 | 16.8 | 30,675 | 17.4 | 704 | 16.3 | 33,308 | 17.5 |
| Asian/Pacific Islander | 1,051 | 4.7 | 7,383 | 4.2 | 204 | 4.7 | 8,045 | 4.2 |
| Other | 617 | 2.8 | 4,031 | 2.3 | 119 | 2.8 | 4,317 | 2.3 |
| Unknown | 936 | 4.2 | 7,367 | 4.2 | 160 | 3.7 | 8,062 | 4.2 |
| Maternal age | ||||||||
| <20 | 3,191 | 14.4 | 16,195 | 9.2 | 640 | 14.8 | 16,903 | 8.9 |
| 20–24 | 6,654 | 29.9 | 44,894 | 25.5 | 1,260 | 29.2 | 48,094 | 25.2 |
| 25–29 | 5,725 | 25.7 | 49,415 | 28.1 | 1,067 | 24.7 | 54,037 | 28.3 |
| 30–34 | 3,865 | 17.4 | 39,623 | 22.5 | 752 | 17.4 | 43,399 | 22.7 |
| ≥35 | 2,782 | 12.5 | 25,700 | 14.6 | 597 | 13.8 | 28,157 | 14.8 |
| Unknown | 22 | 0.1 | 237 | 0.1 | 6 | 0.1 | 260 | 0.1 |
| Marital status | ||||||||
| Not Married | 11,155 | 50.2 | 66,031 | 37.5 | 2,283 | 52.8 | 69,627 | 36.5 |
| Married | 10,316 | 46.4 | 104,425 | 59.3 | 1,882 | 43.5 | 115,196 | 60.4 |
| Unknown | 768 | 3.5 | 5,608 | 3.2 | 157 | 3.6 | 6,027 | 3.2 |
| Parity | ||||||||
| 0 | 11,224 | 50.5 | 69,876 | 39.7 | 2,157 | 49.9 | 75,561 | 39.6 |
| 1 | 5,667 | 25.5 | 54,371 | 30.9 | 1,067 | 24.7 | 59,558 | 31.2 |
| ≥2 | 5,348 | 24.1 | 51,817 | 29.4 | 1,098 | 25.4 | 55,731 | 29.2 |
| Pre-pregnancy BMI | ||||||||
| <18.5 | 1,327 | 6.0 | 6,239 | 3.5 | 305 | 7.1 | 6,631 | 3.5 |
| 18.5–24.9 | 7,914 | 35.6 | 64,165 | 36.4 | 1,498 | 34.7 | 69,243 | 36.3 |
| 25–29.9 | 2,852 | 12.8 | 26,349 | 15.0 | 537 | 12.4 | 29,084 | 15.2 |
| ≥30 | 2,317 | 10.4 | 21,114 | 12.0 | 458 | 10.6 | 23,600 | 12.4 |
| Unknown | 7,829 | 35.2 | 58,197 | 33.1 | 1,524 | 35.3 | 62,292 | 32.6 |
| Smoking during pregnancy | 2,475 | 11.1 | 11,364 | 6.5 | 596 | 13.8 | 11,590 | 6.1 |
| Alcohol use during pregnancy | 525 | 2.4 | 3,176 | 1.8 | 127 | 2.9 | 3,270 | 1.7 |
| Gestational complications | 2,417 | 10.9 | 16,044 | 9.1 | 585 | 13.5 | 16,157 | 8.5 |
| Comorbidity | 3,246 | 14.6 | 22,733 | 12.9 | 696 | 16.1 | 23,929 | 12.5 |
| Insurance type | ||||||||
| Private insurance | 10,411 | 46.8 | 99,171 | 56.3 | 1,850 | 42.8 | 109,068 | 57.2 |
| No private insurance | 9,410 | 42.3 | 58,253 | 33.1 | 1,997 | 46.2 | 61,579 | 32.3 |
| Unknown | 2,418 | 10.9 | 18,640 | 10.6 | 475 | 11.0 | 20,203 | 10.6 |
| Season of conception | ||||||||
| Spring (March–May) | 5,276 | 23.7 | 41,450 | 23.5 | 1,023 | 23.7 | 45,230 | 23.7 |
| Summer (June–August) | 5,540 | 24.9 | 45,423 | 25.8 | 1,072 | 24.8 | 49,268 | 25.8 |
| Fall (September–November) | 6,163 | 27.7 | 48,551 | 27.6 | 1,191 | 27.6 | 52,850 | 27.7 |
| Winter (December–February) | 5,260 | 23.7 | 40,640 | 23.1 | 1,036 | 24.0 | 43,502 | 22.8 |
Abbreviations: AGA, appropriate for gestational age; BMI, body mass index; tLBW, term low birthweight; SGA, small for gestational age.