Table 2.
Mean Age at Menarche, at First Use of Oral Contraceptives (OC), and at First Cigarette Among Female Israeli Army Recruits, 1986–2000, by Birth Year
| Birth year | Age in years at menarche | Age in years at first OC use | Age in years at first cigarette |
|---|---|---|---|
| Mean (SD) | Mean (SD) | Mean (SD) | |
| <1970 | 13.41 (1.30) | 17.49 (0.81) | 16.68 (1.30) |
| 1970-1972 | 13.31 (1.29) | 17.43 (0.85) | 16.54 (1.15) |
| 1973-1975 | 13.19 (1.30) | 17.41 (0.83) | 16.35 (1.33) |
| 1976-1978 | 13.10 (1.27) | 17.30 (0.95) | 16.17 (1.40) |
| >1978 | 13.03 (1.28) | 17.14 (1.05) | 15.85 (1.36) |