Table 3. Descriptive statistics of continuous variables for clinical pregnancy and non-clinical pregnancy groups.

Variable	Pregnancy	No pregnancy	p-value
	(N = 6548)	(N = 10,740)
	(M±SD)	(M±SD)
Duration of infertility (years)	3.73±2.75	4.24±3.04	***
Number of IVF cycles performed	0.99±1.48	1.27±1.77	***
Number of oocytes retrieved	6.96±7.22	5.17±6.02	***
Embryos	5.62±4.11	4.23±3.38	***
The Number of Embryos Transferred	2.66±0.89	2.58±1.01	***
The Total Number of Frozen Embryos	2.79±3.76	1.53±3.00	***
Female age (years)	36.07±3.85	37.94±4.34	***
Male age (years)	38.29±5.02	39.87±5.52	***

Abbreviations: M, mean; SD, standard deviation; IVF, in vitro fertilization

*** p < 0.001 by Student’s t-test for continuous variables.