Table 1.
Characteristics of the Study Population by Cohort (NHS/NHSII) and Self-Reported Birth Weight. Presented as mean(sd) or %.
| Birth Weight | ||||||
|---|---|---|---|---|---|---|
| <5.5 lbs | 5.5–7 lbs | 7–8.5 lbs | 8.5–10 lbs | >10 lbs | Not Sure | |
| NHS Participants (1976) | 7052 (8.1%) | 21632 (24.8%) | 31525 (36.1%) | 7788 (8.9%) | 1672 (1.9%) | 17742 (20.3%) |
| Age at baseline (yrs) | 42 (7.1) | 42 (7.1) | 42 (7.1) | 43 (7.1) | 45 (6.6) | 46 (6.6) |
| Mother Smoked in Home | 28.0 | 24.5 | 22.9 | 21.8 | 17.7 | 20.2 |
| Father Smoked in Home | 64.8 | 62.6 | 62.2 | 62.6 | 61.4 | 59.9 |
| BMI at age 18 | 18.7 (7.3) | 18.7 (7.1) | 19.3 (7.1) | 19.4 (7.4) | 19.9 (8.0) | 18.6 (7.4) |
| BMI at baseline | 23.4 (4.8) | 23.1 (4.4) | 23.5 (4.6) | 24.0 (4.8) | 24.5 (5.3) | 23.5 (4.5) |
| Maternal Diabetes | 9.1 | 8.7 | 9.5 | 12.2 | 18.0 | 10.5 |
| Father’s Occupation | ||||||
| Laborer/Farmer | 10.1 | 10.3 | 11.0 | 12.6 | 13.6 | 13.8 |
| Crafts/Service/Home | 19.9 | 19.3 | 19.5 | 20.1 | 22.8 | 20.9 |
| Clerical/Sales | 34.6 | 34.3 | 34.1 | 33.6 | 33.4 | 30.5 |
| Professional/Managerial | 25.9 | 27.5 | 26.9 | 24.6 | 19.8 | 21.8 |
| Mother’s Occupation | ||||||
| Laborer/Farmer | 0.4 | 0.4 | 0.4 | 0.4 | 0.7 | 0.7 |
| Crafts/Service | 10.8 | 9.8 | 9.5 | 10.4 | 11.3 | 10.5 |
| Clerical/Sales | 12.3 | 11.6 | 11.6 | 11.1 | 10.5 | 8.6 |
| Professional/Managerial | 9.4 | 9.2 | 9.3 | 8.3 | 8.1 | 6.8 |
| Housewife | 61.6 | 64.9 | 65.2 | 65.6 | 64.2 | 63.5 |
| African-American | 1.1 | 1.3 | 0.8 | 0.9 | 1.2 | 2.4 |
| Hispanic | 0.7 | 0.6 | 0.5 | 0.4 | 0.4 | 0.9 |
| NHSII Participants (1989) | 6542 (6.7%) | 27577 (28.0%) | 44321 (45.0%) | 11205 (11.4%) | 1171 (1.2%) | 7597 (7.7%) |
| Age at Baseline (yrs) | 35 (4.6) | 34 (4.7) | 34 (4.7) | 34 (4.7) | 34 (4.6) | 35 (4.5) |
| Mom Smoked while Pregnant | 44.9 | 34.9 | 24.0 | 18.1 | 11.3 | 24.9 |
| Mom Smoked in Home | 51.1 | 42.4 | 33.0 | 27.7 | 20.4 | 35.2 |
| Dad Smoked in Home | 63.8 | 59.3 | 55.3 | 53.7 | 49.5 | 54.6 |
| BMI at age 18 | 21.2 (3.6) | 21.1 (3.3) | 21.3 (3.3) | 21.7 (3.4) | 22.4 (4.1) | 21.1 (3.2) |
| BMI at baseline | 24.4 (5.5) | 23.9 (5.0) | 24.1 (5.0) | 24.5 (5.2) | 25.3 (5.9) | 23.9 (4.8) |
| Maternal Diabetes | 7.3 | 6.1 | 6.7 | 9.8 | 18.7 | 7.5 |
| African-American | 2.0 | 1.8 | 1.2 | 1.0 | 2.2 | 3.3 |
| Hispanic | 1.6 | 1.5 | 1.2 | 1.4 | 1.5 | 2.6 |