In preimplantation genetic diagnosis (PGD), embryos are created by IVF and cells removed from these embryos for genetic analysis. Until recently, testing was solely for the disease the couple carried. The use of array-comparative genomic hybridisation and single nucleotide polymorphism arrays has entered the PGD arena. These techniques allow all chromosomes and many genes to be examined. The analysis of the whole genome prior to implantation brings ethical concerns. Will healthy couples opt for PGD to select their ‘best’ offspring? This lecture marks International Women’s Day - 8 March