Table 2. Ovarian response and embryo development for day-3 vs. day-5 embryo transfers.
Characteristic Day-3 embryo transfer Day-5 embryo transfer
Total dosage of rFSH (IU) 1665.0±557.5 1836.6±545.8
Duration of stimulation (Days) 7.8±1 7.9±1.1
Final estradiol level (pg/mL) 2054.9±766.1a 2877.5±1331.2b
Number of follicles 14.0±7.7a 24.2±9.9b
Number of retrieved oocytes 8.5±4.2a 13.5±5.8b
Number of mature oocytes 6.6±3.5a 10.4±4.0b
Number of fertilized oocytes 5.1±2.9a 8.6±3.7b
Number of embryos on day-3 5.0±2.8a (98%) 8.4±3.7b (99.2%)
(% fertilized oocytes)
Grade-1 embryo 2.1±2.0a (40.3%) 5.0±2.4b (56.2%)
Grade-2 embryo 1.8±1.8a (35.4%) 3.0±2.8b (30.2%)
Grade-3 embryo 1.2±1.3 (22.3%) 1.6±2.0 (12.9%)
Number of blastocyst on day 5 N/A 5.2±2.8 (73%)
(% of day-3 embryos)
Grade A N/A 0.4±0.7 (4.7%)
Grade B N/A 2.6±1.9 (29.6%)
Grade C N/A 3.4±2.2 (38.7%)
Number of embryo transfer 2.3±0.7a 2.1±0.4b
Endometrial thickness (mm) 10.7±2.2 10.6±2.6

Different superscripts denote statistical difference (p<0.01).