Table 5.

Effects of pre-pregnancy maternal BMI on primary perinatal outcomes: results from multivariate logistic model analyses in subgroups.

	Fresh embryo transfer		Frozen embryo transfer		P for interaction
	Crude OR (95% CI), P-value	Adjusted OR (95% CI), P-value	Crude OR (95% CI), P-value	Adjusted OR (95% CI), P-value
PTB
BMI	1.04 (1.00, 1.08), 0.041	1.03 (0.99, 1.08), 0.188a	1.11 (1.07, 1.16), <0.001	1.09 (1.04, 1.15), <0.001a	0.030a
LBW
BMI	1.02 (0.97, 1.07), 0.494	0.96 (0.89, 1.03), 0.257b	1.09 (1.04, 1.15), 0.001	1.01 (0.91, 1.11), 0.902b	0.428b
Macrosomia
BMI	1.13 (1.09, 1.16), <0.001	1.15 (1.11, 1.20), <0.001b	1.07 (1.03, 1.11), 0.001	1.10 (1.06, 1.15), <0.001b	0.105b
SGA
BMI	0.96 (0.92, 0.99), 0.025	0.95 (0.90, 0.99), 0.016a	0.99 (0.93, 1.04), 0.645	0.99 (0.93, 1.06), 0.726a	0.334a
LGA
BMI	1.13 (1.10, 1.17), <0.001	1.14 (1.10, 1.18), <0.001a	1.08 (1.04, 1.11), <0.001	1.09 (1.04, 1.13), <0.001a	0.030a

^aModel adjusted all baseline variates (year of embryo transfer, maternal age, gravidity, parity, main etiology of infertility, sperm donation, fertilization method, fresh/frozen embryo transfer, blastocyst/cleavage-stage transfer, assisted hatching, antral follicle count, basal serum FSH level, endometrial thickness, maternal smoking history, and gestational weight gain).

^bModel adjusted all baseline variates and gestational age.