Table 4: Cycle parameters, clinical pregnancies and deliveries in frozen-thawed cycles (n=273)
Parameter Clinical Pregnancy P value Live Birth P value
  Yes No Yes No
Fresh cycle protocol type   0.34* 0.21*    
Oocytes retrieved 15.46 ± 6.4 13.81 ± 5.8 0.04** 15.31 ± 6.4 14.01 ± 5.9 0.16**
Oocytes fertilized 11.33 ± 5.4 9.65 ± 4.7 0.01** 11.09 ± 5.3 9.88 ± 4.8 0.10**
Cleaved embryos 9.45 ± 4.3 8.34 ± 3.8 0.04** 9.41 ± 4.4 8.46 ± 3.8 0.12**
Number of embryos frozen in fresh cycle 6.64 ± 4.4 5.31 ± 3.7 0.01** 6.7 ± 4.4 5.43 ± 3.8 0.03**
Number of embryos thawed 2.67 ± 1.1 2.98 ± 1.5 0.11** 2.70 ± 1.1 2.94 ± 1.5 0.27**
Number of embryos transferred after thawing 2.01 ± 0.7 2.11 ± 0.7 0.33** 2.00 ± 0.6 2.11 ± 0.8 0.36**
Assisted hatching performed (%) 6.6 14.7 0.07* 7.4 13.7 0.21*
Mode of endometrial preparation for FET            
Spontaneous (n=21) 6 (7.9%) 15 (7.7%) 1.0*** 5 (9.3%) 16 (7.4%) 0.67***
Artificial (n=249) 70 (92.1%) 179 (91.8%)   49 (90.7%) 200 (92.2%)  
Mean endometrial thickness (cm) 0.972 0.9914 0.47** 0.9881 0.9854 0.93**
Max Estradiol (pmol/l) 1724.7 1427 0.15** 1720.6 1458.1 0.26**
* x2-test     **t-test     ***Fisher’s exact test