Table 2. Average weight change (kg) between first and third pregnancy in relation to BMI classification at baseline (first) and third pregnancy.

Within baseline BMI category columns percentage of women per BMI category at third pregnancy in square brackets.

	BMI category at first pregnancy (number of women)
BMI category at third pregnancy	Underweight	Normal	Overweight	Obese
	n = 91	n = 3117	n = 1357	n = 514
Underweight	0.76±0.930 [23.1%]	-5.28±1.15 [0.4%]	n/a [0%]	n/a [0%]
Normal	7.19±0.510 [73.6%]	2.19±0.09 [64.2%]	-4.96±0.49 [10.7%]	-20.46±4.19 [1.2%]
Overweight	18.40±2.49 [3.3%]	9.06±0.13 [30.6%]	2.57±0.22 [52.3%]	-7.03±1.30 [12.0%]
Obese	n/a [0%]	21.77±0.33 [4.8%]	14.51±0.27 [36.9%]	9.53±0.47 [86.8%]

Maternal weight measured at the first and third pregnancy booking appointment was adjusted to a standard gestational age for all women as detailed previously [13,15].Weight change (fitted mean ± SEM) 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 third pregnancy and inter- delivery interval between first and third pregnancy.