Table 1. List of fields included in database.

Field title in database	Data entry
General information
Centre number
Disease name
Disease category	1=Autosomal recessive; 2=Autosomal dominant, 3=X-linked recessive, 4=X-linked dominant
Cycle number
Embryo information for PGD cycle
Embryo ID	Embryo identification for PGD cycle
Fertilization PN number	0, 1, 2, 3
Day PGD biopsy
Number cells on which PGD results based	1, 2, etc
Embryo morphologya grade at PGD	1=best, & 4=poorest
Genetic analysis for PGD and reanalysis
PGD genotype	M=pathological allele; N=normal
PGD embryo status	1=not affected; 2=affected; 3=aberrantb
Reanalysis genotype	M=pathological allele; N=normal
Reanalysis embryo status	1=not affected; 2=affected; 3=aberrantb
Conditions of reanalysis, assay type, and outcome(s)
Day reanalysis
Embryo morphologya grade at reanalysis	1=best, & 4=poorest
Number cells reanalysed	indicate if whole embryo
Reanalysis result CONCORDANT STATUS	Y/N
Possible reason discordancy	1=ADO; 2=contamination; 3=mosaicism; 4=other
Assay type	1=multiplex; 2=singleplex

^aEmbryo morphology was categorized in to four subgroups, with grade 1 being the quartile embryos of best morphology, and grade 4 the quartile embryos of poorest morphology (according to the Alpha Scientists in Reproductive Medicine and ESHRE Special Interest Group of Embryology consensus for embryo morphology assessment scoring criteria in each centre¹⁰).

^bAberrant: This refers to analysis using linkage marker protocols, when an embryo may be classified as likely having abnormal ploidy (eg trisomy) based on marker analysis; the genotype for the specific disease may also be ‘unaffected'.