Table 2.

Associations between risk of recurrent large-for-gestational age (LGA) birth in the second pregnancy and change in maternal body mass index (BMI) between pregnancies as measured at the first antenatal visit of each pregnancy stratified by BMI category in the first pregnancy

Maternal BMI change (categorised)		Full sample			Normal weight at first pregnancy			Overweight at first pregnancy			Obese at first pregnancy
		Total n, No of cases	Relative risk, (RR)*	95% CI	Total n, No of cases	RR*	95% CI	Total n, No of cases	RR*	95% CI	Total n, No of cases	RR*	95% CI
Total unadjusted n, No of cases		1109, 530			521, 234			338, 170			236, 122
Lost ≤ −1 kg/m2 from previous pregnancy	Unadjusted	188, 83	0.89	0.74 to 1.08	45, 17	0.80	0.54 to 1.20	74, 30	0.68	0.50 to 0.94	69, 36	1.16	0.79 to 1.69
	Adjusted†	178, 78	0.88	0.72 to 1.07	44, 16	0.79	0.54 to 1.17	68, 27	0.69	0.48 to 0.97	66, 35	1.21	0.79 to 1.83
Weight stable (> –1 to <1 kg/m2)	Unadjusted	365, 181	Ref		212, 100	Ref		98, 58	Ref		51, 23	Ref
	Adjusted†	353, 176	Ref		204, 96	Ref		97, 57	Ref		49, 23	Ref
Gained 1–3 kg/m2 from previous pregnancy	Unadjusted	313, 150	0.97	0.83 to 1.13	162, 74	0.97	0.78 to 1.21	90, 43	0.81	0.62 to 1.06	55, 31	1.25	0.85 to 1.83
	Adjusted†	301, 142	0.98	0.84 to 1.15	156, 70	1.02	0.83 to 1.27	86, 40	0.81	0.61 to 1.08	53, 30	1.28	0.86 to 1.91
Gained ≥3 kg/m2 from previous pregnancy	Unadjusted	243, 116	0.96	0.81 to 1.14	102, 43	0.89	0.68 to 1.17	76, 39	0.87	0.66 to 1.14	61, 32	1.16	0.79 to 1.71
	Adjusted†	234, 111	1.00	0.83 to 1.20	96, 39	0.91	0.68 to 1.21	73, 38	0.91	0.67 to 1.25	61, 32	1.28	0.84 to 1.94

*Generalised linear model with log link and robust variance estimator used to derive RR.

†Adjusted for maternal age, ethnicity, highest educational qualification, whether undergone infertility treatment, smoking status, employment status, baseline BMI, gestational diabetes in current pregnancy and interpregnancy interval.

Bold fonts indicate statistical significance at 0.05 level.