Table 1.
Pre-pregnancy characteristics of the study participants by smoking status
| Maternal characteristics | Women who never smoked (N = 405) |
Women who quit smoking (N = 61) |
Women who continued to smoke (N = 43) |
P-valuea |
|---|---|---|---|---|
| Age (years), mean (SD) | 31.3 (5.0) | 28.8 (6.3) | 27.0 (4.5) | < .001 |
| Education (%) | < .001 | |||
| High school or less | 8.4 | 27.9 | 48.8 | |
| Community college or some university | 43.2 | 54.1 | 41.9 | |
| At least bachelor’s degree | 48.4 | 18.0 | 9.3 | |
| Household income (%) | < .001 | |||
| Less than $20,000 | 5.9 | 16.4 | 25.6 | |
| $20,000–$80,000 | 33.9 | 49.2 | 34.9 | |
| Over $80,000 | 47.8 | 24.6 | 16.3 | |
| Preferred not to answer | 12.4 | 9.8 | 23.3 | |
| Married, common-law or living with partner (%) | 93.8 | 80.3 | 65.1 | < .001 |
| Caucasian (%) | 78.2 | 88.5 | 85.7 | .12 |
| Nulliparous (%) | 45.0 | 61.7 | 31.7 | .01 |
| BMI (kg/m2), mean (SD) | 25.7 (5.5) | 25.5 (6.6) | 27.0 (7.2) | .26 |
| BMI class (%) | .03 | |||
| Underweight (<18.5 kg/m2) | 3.0 | 1.6 | 7.0 | |
| Normal (18.5–24.9 kg/m2) | 51.6 | 62.3 | 44.2 | |
| Overweight (25.0–29.9 kg/m2) | 26.4 | 24.6 | 14.0 | |
| Obese (≥30.0 kg/m2) | 19.0 | 11.5 | 34.9 |
Abbreviation(s): BMI body mass index
a P values were calculated with ANOVA for continuous variables and with Fisher’s exact test for categorical variables