Table 2. Rate of First Childbirth, Age at First Childbirth, and Cumulative Probability of First Childbirth Among Physicians and Nonphysicians Observed From Age 15 Years.
| Outcome | Nonphysicians (n = 26 640) | Physicians | ||
|---|---|---|---|---|
| Total (n = 5328) | Family physicians (n = 2442) | Specialists (n = 1878) | ||
| Follow-up, median (IQR), y | 14.8 (11.6-17.9) | 16.7 (14.7-19.1) | 16.5 (14.6-18.8) | 17.9 (16.1-20.3) |
| Rate of childbirth per 100 person-years | 3.40 | 2.31 | 2.83 | 2.42 |
| Time to childbirth, median (95% CI), y | 32.7 (32.5-32.9) | 34.7 (34.5-35.0) | 33.6 (33.4-33.9) | 35.6 (35.2-36.0) |
| Age at first childbirth, median (IQR),a y | 27.0 (22.6-30.2) | 31.6 (29.8-33.6) | 31.4 (29.6-33.3) | 32.1 (30.4-34.2) |
| Cumulative probability of childbirth, % | ||||
| At 20 y | 6.2 | 0.1 | 0.02 | 0.01 |
| At 25 y | 18.6 | 0.5 | 0.05 | 0.04 |
| At 30 y | 37.7 | 12.3 | 16.1 | 9.4 |
| At 35 y | 57.8 | 52.0 | 61.3 | 46.2 |
| At 40 y | 65.2 | 70.1 | 76.7 | 67.8 |
Abbreviation: IQR, interquartile range.
a
Age at first childbirth among women who experienced a first childbirth during observed follow-up.