Characteristics of participants and non-participants, pregnant women attending routine antenatal care. Aarhus, Denmark, 1998
| Participants (n=441) | Non-participants (n=37) | |
| Mean age (SD) | 30.0 (4.5) | 30.2 (6.2) |
| Mean prepregnancy body mass index (SD)1-150 | 23.0 (3.7) | 23.0 (4.7) |
| Mean number of cigarettes/day (SD) (among smokers before pregnancy)1-151 | 12 (6.3) | 13 (4.8) |
| Mean number of cigarettes/day (SD) (among current smokers)1-152 | 7 (4.3) | 10 (5.8) |
| Median gestational age (weeks) at interview/enrolment1-153 | 15.0 | 15.4 |
| Median gestational age (weeks) when filling in the questionnaire | 11.0 | 11.3 |
| Mean birthweight of child, grammes (SD)1-154 | 3551 (577) | 3599 (504) |
| Mean length of child at birth, cm (SD)1-154 | 51.8 (2.8) | 51.9 (1.9) |
| Mean gestational age (weeks) at delivery (SD)1-154 | 39.6 (2.0) | 39.6 (1.6) |
| Smokers (before pregnancy)1-159 | 32% | 30% |
| Smokers (current)1-152 | 17% | 22% |
| Chronic diseases1-160 | 7% | 5% |
| Used medicine within past 3 months before pregnancy1-164 | 27% | 22% |
| Employed1-161 | 67% | 66% |
| Students1-161 | 18% | 20% |
↵1-150 Information missing for one participant.
↵1-151 Information missing for six smokers (five participants, one non-participant).
↵1-152 Information missing for seven participants.
↵1-153 Information missing for two non-participants.
↵1-154 Live, singleton births only.
↵1-159 Information missing for 22 participants.
↵1-160 Hypertension, diabetes, epilepsy, rheumatism, arthritis, heart, lung, metabolic, or kidney disease.
↵1-164 Information missing for two participants.
↵1-161 Information missing for six participants and two non-participants.