Supplementary Table 1.

Predictors of sperm retrieval failure via univariate logistic regression

Characteristic	OR (95% CI)	P
Age (year)	0.96 (0.83–1.12)	0.606
Testis volume (ml)	0.79 (0.66–0.95)	0.012
PRL (mIU l−1)	1.00 (1.00–1.00)	0.328
FSH (IU l−1)	1.00 (0.96–1.04)	0.884
LH (IU l−1)	1.08 (1.00–1.17)	0.061
E2 (pmol l−1)	1.00 (0.99–1.01)	0.820
Testosterone (nmol l−1)	0.95 (0.88–1.03)	0.194
Inhibin B (pg ml−1)	1.00 (0.97–1.02)	0.856

OR: odds ratio; CI: confidence interval; PRL: prolactin; FSH: follicle-stimulating hormone; LH: luteinizing hormone; E2: estradiol