Table 1.
Description of the study population
| Variable | Cases | Controls | P value |
|---|---|---|---|
| Marital status, n (%) | .036 | ||
| Single | 37 (7.1) | 42 (8.1) | |
| Stable couple | 161 (31.1) | 124 (23.9) | |
| Married | 320 (61.8) | 352 (68.0) | |
| Education level, n (%) | .084 | ||
| Primary | 112 (21.6) | 93 (17.9) | |
| High school, not completed | 42 (8.1) | 28 (5.4) | |
| High school, completed | 185 (35.7) | 190 (36.7) | |
| University | 179 (34.6) | 207 (40.0) | |
| Previous preterm/low‐birthweight newborn, n (%) | 454 (87.6) | 492 (95.0) | <.001 |
| Kessner index (prenatal care), n (%) | .737 | ||
| Adequate | 259 (50.0) | 253 (48.8) | |
| Intermediate | 185 (35.7) | 182 (35.2) | |
| Inadequate | 74 (14.3) | 83 (16.0) | |
| Smoking during pregnancy, n (%) | 149 (28.8) | 80 (15.4) | <.001 |
| Pre‐eclampsia, n (%) | 46 (8.9) | 11 (2.1) | <.001 |
| Intrauterine growth retardation, n (%) | 141 (27.2) | 8 (1.5) | <.001 |
| Weight gain during pregnancy (g/week), mean (SD) | 278 (121) | 310 (114) | <.001 |
| Body mass index, mean (SD) | 23.1 (4.5) | 23.9 (4.1) | <.001 |
| Alcohol intake (g/week), mean (SD) | 4.2 (18.5) | 3.1 (15.2) | .312 |