Table 1.
Characteristics in early pregnant women and a population based referent group
| Pregnant women | Referent women | Pregnant vs referent women | |||||
|---|---|---|---|---|---|---|---|
| <35 years | ≥35 years | <35 years | ≥35 years | ||||
| (n = 176) | (n = 33) | p -value | (n = 103) | (n = 103) | p -value | p -value | |
| Age (mean (95% CI))1 | 29.2 (28.7 –29.7) | 37.0 (36.4-37.6) | - | 30.1 (30.0-30.2) | 40.0 (40.0 – 40.0) | - | <0.0014 |
| Married or cohabitant (%)2 | 94.5 | 100 | 0.359 | 90.3 | 75.5 | 0.001 | 0.302 |
| Education (% with university)2 | 59.5 | 77.4 | 0.059 | 35.9 | 60.8 | <0.001 | <0.001 |
| BMI (mean (95% CI))1 | 24.1 (23.3-24.8) | 25.0 (23.3-26.8) | 0.330 | 25.9 (24.8-26.9) | 24.5 (23.4-25.6) | 0.085 | 0.179 |
| Normal weight BMI < 24.9 (%)2 | 71.4 | 61.3 | 0.354 | 54.4 | 68.9 | 0.099 | 0.096 |
| Overweight BMI ≥25.0-29.9 (%) | 20.5 | 32.3 | 29.1 | 19.4 | |||
| Obese BMI ≥ 30.0 (%) | 8.1 | 6.5 | 16.5 | 11.7 | |||
| Smoking (% smoker)2 | 0.0 | 3.2 | 0.160 | 6.8 | 5.8 | 0.774 | 0.017 |
| Snuff use (% user)2 | 1.2 | 0.0 | 1.000 | 17.5 | 7.8 | 0.036 | <0.001 |
| Alcohol g/day (median (min – max))3 | 0.11 (0–15.0) | 1.8 (0–13.7) | 0.028 | 1.8 (0–21.2) | 2.5 (0–19.4) | <0.001 | <0.001 |
| Alcohol No (%)2 | 38.6 | 21.2 | 0.041 | 12.6 | 4.9 | 0.040 | <0.001 |
| Low physical activity at work (%)2 | 27.3 | 45.5 | 0.037 | 25.2 | 34.0 | 0.170 | 0.330 |
| Low physical activity at leisure activity (%)2 | 57.1 | 60.0 | 0.771 | 56.3 | 38.9 | 0.012 | 0.237 |
| Low physical activity at work and leisure time (%)2 | 15.9 | 27.3 | 0.117 | 21.4 | 15.5 | 0.281 | 0.868 |
1Differences between means were tested with two-sided Student’s t-test. Means for BMI in age groups were adjusted for education level using a generalized linear model. For comparisons between all pregnant and referent women mean values were adjusted for education and age group using a generalized linear model.
2Differences in sampling distribution were tested with Pearson’s Chi-square test or Fischer’s exact test if five or fewer observations in a cell; For BMI groups (normal weight, overweight, obesity) differences in sample distribution were tested among all tree levels.
3Data, which are based on FFQ information, were not normally distributed. Differences between age groups were tested with Mann–Whitney U test.
4The difference in mean age between pregnant and referent women was statistically significant in both age strata (p < 0.01).