Table I.
Characteristics of women in the Collaborative Perinatal Project who planned their pregnancies (planners) compared to those who did not (non-planners). Women in the Collaborative Perinatal Project were enrolled at 12 study centers in the United States from 1959–1965.
| Characteristic | Planners (N = 8,514)
|
Non-Planners (N = 39,683)
|
|---|---|---|
| % or Median (Q1, Q3)* | % or Median (Q1, Q3) | |
| BMI† | 21.3 (19.3, 23.8) | 21.5 (19.4, 24.5) |
| Underweight (<18.5kg/m2) | 17 | 15 |
| Optimal weight (18.5–24.9 kg/m2) | 63 | 60 |
| Overweight (25.0–29.9 kg/m2) | 11 | 13 |
| Obese (≥30kg/m2) | 8 | 8 |
| Age (years) | 23 (20, 27) | 23 (19, 28) |
| <20 | 20 | 26 |
| 20–23 | 25 | 23 |
| 23–27 | 32 | 25 |
| ≥28 | 23 | 26 |
| Current smokers | 46 | 46 |
| Prior Pregnancies | ||
| 0 | 40 | 32 |
| 1 | 27 | 18 |
| 2+ | 33 | 47 |
| Prior Miscarriages among women with prior pregnancy | ||
| 0 | 67 | 74 |
| 1 | 24 | 19 |
| 2+ | 9 | 7 |
| Irregular cycles | 8 | 11 |
| Occupation | ||
| Never worked | 13 | 16 |
| White collar | 44 | 27 |
| Blue collar | 44 | 56 |
| Maternal Education | ||
| Elementary | 17 | 19 |
| < High school | 32 | 41 |
| High school | 33 | 29 |
| > High school | 18.5 | 11 |
| Race | ||
| White | 64 | 42 |
| Non-white | 36 | 58 |
*
Q = quartile
†
BMI = body mass index; categorized into underweight (<18.5 kg/m2), optimal weight (18.5 kg/m2 – 24.9 kg/m2), overweight (25.0 kg/m2– 29.9 kg/m2), and obese (≥30.0 kg/m2).