Table 2 Comparison of FET cycles between the D5 group and D6-on-D5 group
|  | D5 group(n = 1270) | D6-on-D5 group(n = 103) | P-value |
|---|---|---|---|
Maternal age(years) | 31.37 ± 4.42 | 31.89 ± 4.46 | 0.254 |
Paternal age (years) | 33.54 ± 5.08 | 33.88 ± 4.97 | 0.507 |
BMI(kg/m2) | 21.22 ± 2.74 | 21.23 ± 2.67 | 0.978 |
Endometrial thickness(mm) | 9.72 ± 1.46 | 9.82 ± 1.37 | 0.466 |
Number of blastocysts transferred | 1.16 ± 0.37 | 1.39 ± 0.49 | 0.000 |
Type of infertility | Â | Â | Â |
Primary infertility | 47.6%(604) | 41.7% (43) | 0.256 |
Secondary infertility | 52.4%(666) | 58.3% (60) | Â |
Endometrial preparation | Â | Â | Â |
Natural cycles | 40.6% (515) | 38.8% (40) | 0.733 |
HRT cycles | 59.4% (755) | 61.2% (63) | Â |
Number of blastocyst transferred | Â | Â | Â |
Single blastocyst transfer | 84.2% (1069) | 61.2% (63) | 0.000 |
Double blastocyst transfer | 15.8% (201) | 38.8% (40) | Â |
Quality of blastocysts transferred | Â | Â | Â |
Qualified | 12.4% (157) | 41.7% (43) | 0.000 |
Good | 87.6% (1113) | 58.3% (60) | Â |
Clinical pregnancy rate (%) | 66.0(838/1270) | 55.3(57/103) | 0.029 |
Implantation rate (%) | 62.1(913/1471) | 44.8(64/143) | 0.000 |
Early miscarriage rate (%) | 11.2(94/838) | 21.1(12/57) | 0.026 |
Multiple pregnancy rate (%) | 8.9(75/838) | 12.3(7/57) | 0.399 |