Table 3: Baseline patient characteristics, treatment variables, and IVF outcomes of the patients grouped according to the cut-off values for female age and DHEAS level predictive of clinical pregnancy (cutoffs are selected by ROC curve analysis).

Age category (years)<37.5≥37.5
>5.7≤5.7>5.7≤5.7
DHEAS category ( mol/L)Group 1Group 2Group 3Group 4
( )( )( )( )

Patient characteristics
 Age (y)34.0 ± 2.7(3)(4)34.1 ± 1.8(3)(4)39.7 ± 1.7(1)(2)40.5 ± 1.9(1)(2)
 BMI (kg/m2)23.5 ± 3.823.0 ± 3.3(3)(4)26.2 ± 5.0(2)24.5 ± 3.7(2)
 AFC7.0 ± 4.07.4 ± 3.66.0 ± 3.05.8 ± 3.7
 AMH (pmol/L)3.2 ± 1.93.5 ± 1.8(4)2.3 ± 1.52.6 ± 1.6(2)
 DHEAS (µmol/L)7.0 ± 0.7(2)(4)3.6 ± 1.2(1)(3)6.9 ± 0.9(2)(4)3.5 ± 1.4(1)(3)
 FSH (IU/L)9.0 ± 2.99.6 ± 8.39.1 ± 4.110.3 ± 6.9
 LH (IU/L)4.3 ± 1.84.6 ± 2.63.9 ± 1.15.0 ± 2.2
(pmol/L)192 ± 73217 ± 103248 ± 130239 ± 153
(nmol/L)1.9 ± 0.6(2)(4)1.2 ± 0.5(1)(3)2.0 ± 1.9(2)(4)1.3 ± 0.6(1)(3)
Treatment variables
 Duration of stimulation (d)10.7 ± 1.310.3 ± 1.610.6 ± 3.010.7 ± 1.5
 Total gonadotrophins used (IU)3200 ± 3922953 ± 6433167 ± 9013064 ± 633
 Number of ICSI cycles, % ( )73.9 (17/23)72.2 (26/36)71.4 (5/7)76.2 (32/42)
IVF outcomes
 Number of oocytes retrieved3.1 ± 1.4(4)3.2 ± 2.4(4)2.9 ± 1.72.0 ± 1.5(1)(2)
 Number of oocytes eligible for fertilization2.5 ± 0.8(4)2.2 ± 1.1(4)2.11.6(1)(2)
 Number of embryos transferred1.5 ± 1.11.3 ± 1.20.9 ± 1.11.0 ± 0.9
 Implantation rate per embryo transferred (%)32.4(2)(4)8.6(1)(4)12.53.8(1)(2)
 Clinical pregnancy rate per cycle initiated (%)37.5(2)(4)8.9(1)11.12.0(1)

Note: values are presented as mean ± SD. AFC: antral follicle count; AMH: anti-Müllerian hormone; BMI: body mass index Conversion formulas for the AMH, DHEAS, , and values in mass units are as follows: ng/mL = pmol/L: 7.14, g/dL 0.027 = mol/L, pg/mL 3.67 = pmol/L, and ng/dL 0.0347 = mmol/L, respectively. Fisher's exact test, Chi-quadrat test, and Kruskal-Wallis test with post-hoc analysis according to Conover were used for between-group comparison where appropriate. Superscripted numbers in parentheses denote P < 0.05 compared with Group 1; P < 0.05 compared with Group 2; P < 0.05 compared with Group 3; P < 0.05 compared with Group 4.