Outcome parameters

All parameters were classified according to the type of translocation. Patient baseline characteristics and COS parameter are presented in Table ​Table1.1. Transferrable rate was calculated according to the equation: number of normal/balanced embryos/number of embryos biopsied and was the main PGD outcome. Biopsy outcomes of SNP arrays are summarized in Table ​Table2.2. Pregnancy was confirmed 12 days after embryo transfer (ET) if the serum HCG was elevated. Clinical pregnancy was defined as the presence of fetal heartbeat (FHB) in the uterus under transvaginal ultrasound scan.

COS parameters and results

Data are expressed as mean ± SD. Data refer to analyzed cycles that were only those who were completed; cancelled cycles are not included in the analysis

COH controlled ovarian hyperstimulation, Gn gonadotropins, OPU oocyte pick-up, MII metaphase II, FET frozen embryo transfer

*P <0.05; significant difference between Robertsonian translocation group and reciprocal translocation group ( Welch t test with F test for variance performed as appropriate)

Outcomes of biopsied blastocysts

Values are expressed as n (%) or mean ± standard deviation of the mean (95 % confidence interval)

^aSignificant differences (P < 0.05) within translocation type (chi-square test): Pearson = 79.63, P < 0.001

^bSignificant differences (P < 0.05) within maternal age (chi-square test): Pearson = 10.69, P = 0.014

^cStudent’s t test: t = 3.99, P < 0.001