Table 1.
Demographic and birth characteristics of mothers by pre-pregnancy weight group: overweight/obese (OW/OB) and non-OW/OB
| Variable | Total (N = 169) | Non-OW/OB (N = 117) | OW/OB (N = 52) | p value |
|---|---|---|---|---|
| N (%) or median (IQR) | ||||
| BMI | 23.1 (21.1–25.5) | 21.6 (20.2–23.1) | 27.2 (25.7–31.7) | <.001 |
| Pre-pregnancy BMI category | ||||
| Underweight | 7 (4.1%) | 7 (6.0%) | 0 (0.0%) | <.001 |
| Normal | 110 (65.1%) | 110 (94.0%) | 0 (0.0%) | |
| Overweight | 32 (18.9%) | 0 (0.0%) | 32 (61.5%) | |
| Obese | 20 (11.8%) | 0 (0.0%) | 20 (38.5%) | |
| Ethnic Norwegian | 142 (87.1%) | 95 (84.1%) | 47 (94.0%) | 0.13 |
| Maternal education | ||||
| <12 years education | 9 (5.6%) | 4 (3.6%) | 5 (10.4%) | 0.01 |
| 12 years education | 28 (17.5%) | 19 (17.0%) | 9 (18.8%) | |
| >12 years education | 123 (76.9%) | 89 (79.5%) | 34 (70.8%) | |
| Maternal age (years) | 30.0 (27.0–34.0) | 30.0 (27.0–33.0) | 30.0 (27.5–34.0) | 0.90 |
| Parity | ||||
| No prior pregnancies | 83 (49.1%) | 57 (48.7%) | 26 (50.0%) | 0.62 |
| 1 prior child | 53 (31.4%) | 39 (33.3%) | 14 (26.9%) | |
| >1 prior child | 33 (19.5%) | 21 (17.9%) | 12 (23.1%) | |
| Twins | 11 (6.5%) | 8 (6.8%) | 3 (5.8%) | 1.00 |
| Maternal smoking at beginning of pregnancy | ||||
| Never smoker | 111 (66.5%) | 77 (67.0%) | 34 (65.4%) | 0.01 |
| Past smoker | 41 (24.6%) | 28 (24.3%) | 13 (25.0%) | |
| Occasional | 7 (4.2%) | 5 (4.3%) | 2 (3.8%) | |
| Daily smoker ≤10 | 4 (2.4%) | 2 (1.7%) | 2 (3.8%) | |
| Daily smoker >10 | 4 (2.4%) | 3 (2.6%) | 1 (1.9%) | |
| Diabetes | ||||
| No diabetes | 167 (98.8%) | 116 (99.1%) | 51 (98.1%) | 0.21 |
| T1 | 1 (0.6%) | 1 (0.9%) | 0 (0.0%) | |
| T2 | 1 (0.6%) | 0 (0.0%) | 1 (1.9%) | |
| Glucose in urine | 15 (8.9%) | 8 (6.8%) | 7 (13.5%) | 0.16 |
| High BP | 8 (4.7%) | 4 (3.4%) | 4 (7.7%) | 0.25 |
| Gestational weight gain (kg) | 14.0 (10.0–18.0) | 15.0 (12.0–19.0) | 11.0 (8.1–15.0) | <.001 |
| GWG relative to IOM recommendations | ||||
| Low | 12 (10.3%) | 12 (14.6%) | 0 (0.0%) | 0.06 |
| Adequate | 41 (35.3%) | 27 (32.9%) | 14 (41.2%) | |
| Excessive | 63 (54.3%) | 43 (52.4%) | 20 (58.8%) | |
| Gestational age (days) | 278 (254–285) | 279 (256–285) | 277 (253–287) | 0.80 |
| Birth weight (kg) | 3.37 (2.46–3.75) | 3.31 (2.47–3.69) | 3.44 (2.46–3.84) | 0.29 |
| C-section | 50 (29.6%) | 31 (26.5%) | 19 (36.5%) | 0.19 |
| Maternal antibiotics | 52 (32.1%) | 35 (31.0%) | 17 (34.7%) | 0.71 |
| Day of birth | 9 (5.6%) | 6 (5.3%) | 3 (6.1%) | 1.00 |
| Day before birth | 2 (1.2%) | 1 (0.9%) | 1 (2.0%) | 0.51 |
| Week before birth | 6 (3.7%) | 2 (1.8%) | 4 (8.2%) | 0.07 |
| Month before birth | 9 (5.6%) | 6 (5.3%) | 3 (6.1%) | 1.00 |
| >1 month before birth | 26 (16.0%) | 18 (15.9%) | 8 (16.3%) | 1.00 |
| Antibiotics given to newborn | 14 (8.6%) | 7 (6.2%) | 7 (14.3%) | 0.13 |
| Alpha diversity | ||||
| Shannon | 5.7 (5.3–6.1) | 5.7 (5.4–6.1) | 5.5 (5.0–5.9) | 0.05 |
| Observed species | 365 (307–400) | 375 (315–400) | 338 (292.5–385) | 0.04 |
| PD whole tree | 27.3 (23.6–30.1) | 28.5 (24.0–30.6) | 25.9 (21.8–29.4) | 0.04 |