Table 4. Average weight and BMI change in relation to pattern of BMI-change between first, second and third pregnancy.
| Pattern of BMI change between 3 pregnancies | Number of women (% of population) | Weight change–pregnancy 1 to 2 | Weight change–pregnancy 2 to 3 | BMI change–pregnancy 1 to 2 | BMI change–pregnancy 2 to 3 |
|---|---|---|---|---|---|
| Gain-gain | 362 (7.1%) | 10.37±0.196b | 10.67±0.191a | 3.96±0.073b | 4.07±0.072a |
| Gain-stable | 795 (15.6%) | 10.00±0.133b | 0.51±0.129d | 3.79±0.050b | 0.20±0.048d |
| Gain-loss | 151 (2.9%) | 11.97±0.30a | -9.13±0.291e | 4.53±0.113a | -3.48±0.110e |
| Stable-gain | 872 (17.2%) | 0.44±0.128c | 9.65±0.124b | 0.17±0.048c | 3.67±0.047b |
| Stable-stable | 2513 (49.5%) | 0.75±0.074c | 1.28±0.072c | 0.29±0.028c | 0.49±0.027c |
| Stable-loss | 116 (2.3%) | 1.46±0.340c | -8.15±0.330e | 0.55±0.128c | -3.07±0.125e |
| Loss-gain | 125 (2.5%) | -9.29±0.328e | 11.15±0.318a | -3.51±0.123e | 4.25±0.121a |
| Loss-stable | 135 (2.6%) | -7.59±0.315d | 1.79±0.306c | -2.87±0.119d | 0.67±0.116c |
| Loss-loss | 10 (0.2%) | -8.49±1.160de | -9.04±1.12e | -3.18±0.435de | -3.39±0.426e |
| P value | <0.001 | <0.001 | <0.001 | <0.001 |
Maternal weight measured at the first, second and third pregnancy booking appointment was adjusted to a standard gestational age for all women as detailed previously [13,15]. BMI change within each specified inter-pregnancy period defined as loss if BMI decreased by >2 units, gain if BMI increased by >2 units and stable if BMI remained within 2 units of the previous pregnancy value. Weight/BMI change (fitted mean ± SEM) was estimated by general linear model and adjusted for maternal age, height and year of delivery at first pregnancy, booking week and smoking habit at first and second or second and third pregnancy as appropriate and inter-delivery interval between first and second or second and third pregnancy as appropriate.Within columns, means with a different superscript differ at P<0.01 (Tukey pairwise comparisons).