Table 2.
Demographic data of nulliparous and parous women (n = 56 101) in the Norwegian mother and child cohort study, 1999-2008
|
Nulliparous |
Parous |
|
|
|---|---|---|---|
| n = 29 931 | n = 26 170 | p-value | |
| Mean (SD) age at delivery (y) |
28.4 (4.3) |
31.8 (4.1) |
<0.001 |
| Mean (SD) prepregnant BMI (kg/m2) |
23.7 (4.1) |
24.2 (4.2) |
<0.001 |
| Prepregnant BMI categories (%) |
|
|
|
| < 18.5 |
3.2 |
2.5 |
|
| 18.5-25 |
68.7 |
64.1 |
|
| 25-30 |
20.0 |
23.7 |
<0.001 |
| >30 |
8.1 |
9.7 |
|
| Class 1 |
6.0 |
7.2 |
|
| Class II |
1.6 |
1.9 |
|
| Class III |
0.5 |
0.6 |
|
| Mean (SD) height (m) |
1.68 (0.06) |
1.68 (0.06) |
ns |
| Education (%) |
|
|
|
| High school or less |
27.5 |
35.8 |
|
| College 3 years |
43.9 |
41.0 |
|
| Masters and higher |
26.5 |
21.2 |
<0.001 |
| Missing |
2.1 |
2.0 |
|
| Smoking in pregnancy (%) |
|
|
|
| Not smoking |
90.5 |
88.3 |
|
| Occasional smoking |
3.0 |
2.7 |
|
| Daily smoking |
4.7 |
6.5 |
<0.001 |
| Missing |
1.8 |
2.5 |
|
| Mean (SD) gestational weight gain (kg) |
15.5 (6.1) |
14.7 (5.9) |
<0.001 |
| Mean (SD) postpartum weight retention at: |
|
|
|
| 6 months (kg) |
1.2 (5.0) |
1.3 (4.5) |
0.016 |
| 18 months (kg) |
n = 19604§ |
n = 16593§ |
|
| 2.1 (5.7) | 0.8 (5.1) | <0.001 |
§Denotes number of participants available to analyses at 18 months postpartum.