Table 6. Frequency rate and adjusted risk of maternal morbidity, SGA-birth and spontaneous preterm delivery during third pregnancy in relation to change in BMI between three consecutive pregnancies and BMI category at third pregnancy booking.
| Model 1- third pregnancy outcome | |||
| Maternal Morbidity | SGA-birth | Spontaneous Preterm <37weeks | |
| Number of affected pregnancies | 1283 (25.3%) | 402 (7.9%) | 300 (5.9%) |
| Categorical predictors | |||
| BMI gain vs. stable, Pregnancy 1–2 | 1.24 (1.04–1.49)* | 0.69 (0.51–0.95)* | 1.00 (0.67–1.51) |
| BMI loss vs. stable, Pregnancy 1–2 | 0.81 (0.59–1.11) | 1.09 (0.68–1.72) | 1.04 (0.54–2.01) |
| BMI gain vs. stable, Pregnancy 2–3 | 1.35 (1.12–1.61)*** | 1.15 (0.87–1.54) | 0.69 (0.45–1.06) |
| BMI loss vs. stable, Pregnancy 2–3 | 0.88 (0.65–1.20) | 2.23 (1.47–3.39)*** | 0.67 (0.34–1.35) |
| At Pregnancy 3 | |||
| Obese vs. normal | 1.06 (0.77–1.44) | 0.56 (0.33–0.94)* | 0.97 (0.49–1.94) |
| Overweight vs. normal | 1.07 (0.89–1.29) | 0.58 (0.43–0.77)*** | 0.67 (0.43–1.02) |
| Undernourished vs. normal | 0.58 (0.19–1.77) | 1.13 (0.37–3.39) | 2.76 (0.97–7.88) |
| Model 2- third pregnancy outcome | |||
| Maternal Morbidity | SGA-birth | Spontaneous Preterm <37weeks | |
| Number of affected pregnancies | 1283 (25.3%) | 402 (7.9%) | 300 (5.9%) |
| Categorical predictors | |||
| BMI gain vs. stable, Pregnancy 1–2 | 1.22 (1.01–1.46)* | 0.69 (0.49–0.98)* | 0.96 (0.66–1.49) |
| BMI loss vs. stable, Pregnancy 1–2 | 0.79 (0.58–1.09) | 1.12 (0.68–1.84) | 1.04 (0.54–2.01) |
| BMI gain vs. stable, Pregnancy 2–3 | 1.32 (1.01–1.58)** | 1.25 (0.91–1.70) | 0.70 (0.45–1.07) |
| BMI loss vs. stable, Pregnancy 2–3 | 0.92 (0.68–1.25) | 2.18 (1.39–3.43)*** | 0.71 (0.36–1.42) |
| At Pregnancy 3 | |||
| Obese vs. normal | 0.97 (0.70–1.32) | 0.64 (0.36–1.14) | 0.91 (0.45–1.82) |
| Overweight vs. normal | 1.01 (0.84–1.22) | 0.67 (0.49–0.93)* | 0.63 (0.41–0.97) |
| Undernourished vs. normal | 0.57 (0.19–1.76) | 1.19 (0.36–3.93) | 2.78 (0.97–7.91) |
Maternal morbidity if women had one or more complications including pre-eclampsia, gestational hypertension, caesarean delivery or thromboembolism at third maternity. Odds ratios and 95% confidence limits from logistic regression
*P<0.05
**P<0.01
***P<0.001. Model 1 adjusted for baseline BMI at first pregnancy, height, inter-delivery interval between first and second pregnancy, and second and third pregnancy, and maternal age, year of delivery, smoking habit, gestational age and baby gender at third pregnancy. Model 2 additionally adjusted for placental weight.