Adjusted ORs for outcomes during the subsequent pregnancy in relation to interpregnancy BMI change for women from parity 0 to 1
| Decrease of ≥1 BMI units (n=329) OR (95% CI) | No change in BMI units (n=309) OR (95% CI) | Increase of 1 to <3 BMI units (n=328) OR (95% CI) | Increase of ≥3 BMI units (n=189) OR (95% CI) | |
|---|---|---|---|---|
| Birth status | ||||
| Stillborn | 0.973 (0.038 to 24.759) | 1.00 | 2.066 (0.196 to 44.776) | 3.955 (0.372 to 86.065) |
| Birth type | ||||
| Spontaneous vaginal | 0.944 (0.654 to 1.362) | 1.00 | 0.671 (0.470 to 0.954) | 0.727 (0.480 to 1.104) |
| Caesarean | 1.344 (0.890 to 2.040) | 1.00 | 1.534 (1.026 to 2.310) | 1.806 (1.139 to 2.862) |
| Instrumental vaginal | 0.580 (0.297 to 1.104) | 1.00 | 1.107 (0.631 to 1.954) | 0.582 (0.250 to 1.240) |
| Apgar score | ||||
| 5 min Apgar score ≤6 | 2.005 (0.700 to 6.526) | 1.00 | 1.575 (0.518 to 5.282) | 5.197 (1.932 to 16.434) |
| Infant birth weight | ||||
| Macrosomia | 1.202 (0.779 to 1.864) | 1.00 | 1.138 (0.734 to 1.770) | 1.537 (0.939 to 2.505) |
| LBW <2500 g | 2.553 (1.088 to 6.695) | 1.00 | 0.863 (0.288 to 2.581) | 1.734 (0.621 to 5.027) |
| Maternal blood loss | ||||
| Haemorrhage ≥500 mL | 1.078 (0.670 to 1.738) | 1.00 | 1.043 (0.648 to 1.680) | 1.183 (0.682 to 2.026) |
| Peristatus | ||||
| Third-degree/fourth-degree tear* | 0.922 (0.290 to 2.854) | 1.00 | 1.560 (0.582 to 4.411) | 0.848 (0.178 to 3.171) |
| Episiotomy* | 1.074 (0.293 to 3.934) | 1.00 | 3.571 (1.342 to 11.255) | 0.379 (0.020 to 2.415) |
| Obstetric complications | ||||
| GDM† | 1.224 (0.263 to 6.357) | 1.00 | 2.267 (0.48 to 16.006) | 4.211 (0.881 to 29.957) |
| Hypertensive disorders† | 4.626 (0.737 to 89.051) | 1.00 | 3.696 (0.54 to 72.696) | 9.642 (1.517 to 186.621) |
| Labour complications | ||||
| Shoulder dystocia* | 0.768 (0.207 to 2.843) | 1.00 | 1.160 (0.408 to 3.369) | 0.849 (0.235 to 2.839) |
| VBAC‡ | 1.605 (0.476 to 6.210) | 1.00 | 0.256 (0.013 to 1.841) | 0.906 (0.117 to 5.127) |
| Neonatal outcomes | ||||
| Hypoglycaemia | 1.197 (0.312 to 4.901) | 1.00 | 0.976 (0.228 to 4.184) | 1.790 (0.414 to 7.740) |
| Birth trauma | 1.472 (0.482 to 4.944) | 1.00 | 1.108 (0.329 to 3.892) | 0.297 (0.015 to 1.886) |
| Respiratory distress | 2.618 (0.877 to 9.584) | 1.00 | 1.215 (0.317 to 4.971) | 1.196 (0.231 to 5.545) |
Significant results are shown in bold typeface.
The reference group is no change in BMI units.
ORs and 95% CIs from logistic models adjusted for baseline BMI, interpregnancy interval, maternal age, country of birth and smoking.
*Women who had a caesarean excluded (n=856).
†Women who had gestational diabetes and hypertension in the first pregnancy excluded (n=924).
‡Women who had a caesarean for the first pregnancy only (n=231).
BMI, body mass index; GDM, gestational diabetes mellitus; LBW, low birth weight; VBAC, vaginal birth after caesarean.