Table 2.
Proportion of Pubertal Status (Breast and Pubic Hair Development) at Study Entry and End, by Smoke Exposures
| Exposurea | At entry to study
|
At end of study periodb
|
||
|---|---|---|---|---|
| B2+ (15%) | PH2+ (12%) | B2+ (89%) | PH2+ (86%) | |
| Secondhand smoke | ||||
| None | 89 (13%) | 64 (9%) | 631 (90%) | 612 (87%) |
| Low/Moderate | 54 (16%) | 48 (14%) | 301 (88%) | 290 (84%) |
| High | 23 (27%) | 19 (22%) | 72 (85%) | 71 (84%) |
| Maternal prenatal smoking | ||||
| None | 150 (14%) | 115 (11%) | 929 (90%) | 899 (87%) |
| <5cigs/day | 12 (19%) | 13 (20%) | 51 (80%) | 50 (78%) |
| ≥5cigs/day | 4 (13%) | 3 (10%) | 25 (83%) | 25 (83%) |
| Child Cotininec (baseline) | ||||
| Q1: ≤0.25 ug/g | 24 (8%) | 23 (8%) | 263 (92%) | 255 (89%) |
| Q2: 0.26–0.61 ug/g | 40 (14%) | 34 (12%) | 252 (90%) | 250 (89%) |
| Q3: 0.62–2.24 ug/g | 46 (16%) | 28 (10%) | 249 (89%) | 235 (84%) |
| Q4: ≥2.25 ug/g | 56 (20%) | 46 (16%) | 241 (85%) | 234 (83%) |
a
For total N’s by category (denominators), see Table 1
b
Includes girls lost to follow-up before reaching puberty, as well as those not pubertal by last exam.
c
Urinary cotinine, corrected for creatinine
B2+ indicates onset of breast development, defined as Tanner stage 2 or higher; PH2+, onset of pubic hair development, defined as Tanner stage 2 or higher