Effect of body mass index on pregnancy outcomes in a freeze-all policy: an analysis of 22,043 first autologous frozen-thawed embryo transfer cycles in China

Table 4 Results of multiple regression analysis for live birth rates

	OR	95% C.I.	P value
Normal weight	Reference
Underweight	0.91	0.83–0.99	0.034
Overweight	0.92	0.86–0.98	0.013
Obese	0.70	0.62–0.80	< 0.001
Age	0.96	0.96–0.97	< 0.001
Infertility duration	0.97	0.96–0.98	< 0.001
Gravidity	0.96	0.94–0.99	0.005
Parity	0.88	0.79–0.97	0.014
Main cause of infertility
Tubal factor	Reference
PCOS	1.12	1.02–1.23	0.018
Diminish ovarian reserve	1.06	0.94–1.19	0.340
Endometriosis	1.07	0.96–1.18	0.230
Uterine factor	0.75	0.64–0.88	< 0.001
Unexplained	1.07	0.91–1.25	0.410
Male factor	1.20	1.11–1.30	< 0.001
Number of OPU prior to FET	0.92	0.88–0.95	< 0.001
Year of treatment	1.09	1.08–1.11	< 0.001
Number of embryo transferred	2.14	1.93–2.37	< 0.001
Embryo developmental stage at transfer	1.81	1.59–2.05	< 0.001

ISSN: 1741-7015