Cystic fibrosis (CF) is the first monogenic disorder for which single cell preimplantation genetic diagnosis (PGD) has been successfully applied. The spectrum of mutations in CF is extremely heterogeneous, and hence, the development of mutation-specific PGD protocols is impracticable. The current study reports the development and evaluation of a general multiplex marker polymerase chain reaction (PCR) protocol for PGD of CF. Four closely linked highly polymorphic (CA)(n) repeat markers D7S523, D7S486, D7S480 and D7S490, flanking the cystic fibrosis transmembrane regulator (CFTR) gene, were used. In 99% of the single cells tested (100 leukocytes and 50 blastomeres), multiplex PCR results were obtained and the overall allelic drop out (ADO) rate varied from 2 to 5%. After validation for the presence of ADO and additional alleles, 95% of the multiplex PCR results were accepted to construct the marker genotypes. Depending on the genotype of the couple, and taking into account the embryos lost for transfer due to validation criteria (5%), ADO (0-2%) and single recombination (1.1-3%), in general >90% of the embryos could be reliably genotyped by PGD using a single blastomere. The risk of misdiagnosis equals the chance of a double recombination between informative flanking markers and is <0.05%. Therefore, this polymorphic and multi-allelic marker system is a reliable and generally applicable alternative for mutation-directed PGD protocols. Furthermore, it provides a test for the origin of the detected genotype and also gives an indication of the chromosomal ploidy status of the blastomere tested.

Pre‐implantation genetic diagnosis (PGD) is generally defined as the testing of pre‐implantation stage embryos or oocytes for genetic defects. It has been developed for couples whose potential offspring are at risk of severe Mendelian disorders, structural chromosome abnormalities or mitochondrial disorders. Pre‐implantation embryo diagnosis requires in vitro fertilization, embryo biopsy and either using fluorescent in situ hybridization or polymerase chain reaction at the single cell level. Therefore, it is a complex procedure which requires much experience. Aneuploidy screening to improve medically assisted reproduction (in vitro fertilization/intracytoplasmic sperm injection) is a variant type of PGD. The past, present and future of this development are strongly related to the natural occurrence of chromosomal mosaicism in the pre‐implantation embryo. PGD should be included in each reproductive health care programme. It is recognized as an important alternative to pre‐natal diagnosis. However, diagnosis from a single cell remains a technically challenging procedure, and the risk of misdiagnosis cannot be eliminated. An ethical discussion of the question of whether PGD is acceptable at all–the ‘desirability question’–is a rearguard action. Discussion must primarily focus on the conditions of exercising due caution in and the dynamics of PGD.

The ESHRE PGD Consortium was formed in 1997 to survey the practice of preimplantation genetic diagnosis (PGD). Since then, three reports have been published giving an overview on PGD from an ever-increasing number of centres and reporting on an increasing number of PGD cycles and pregnancies and babies born after PGD. After these initial influential publications, important shortcomings were identified primarily on the method of data collection, i.e. with Excel spreadsheets, and in the timing of the collection (cycles were collected in a different time frame from pregnancies and babies, making the follow-up of cycles very difficult). This is why the Steering Committee has made a major investment in developing and implementing a new database in FileMaker Pro 6. It was also decided that cycles would be collected from one calendar year, as well as the pregnancies and babies ensuing from that particular calendar year. This gave us the opportunity to take a closer look at the data collected earlier, and to attempt to improve their quality. This is a report on the corrected data from the first three data collections (I-III) as well as the result of the last data collection (IV) that was completely carried out using the new database.

Infertility care has improved remarkably over the last few decades and has received growing attention from health care providers. Several treatments, including expensive options such as Assisted Reproductive Techniques, are now widely available for routine clinical use. In most cases, adoption of these treatments has occurred without robust cost-effective analyses. IVF for unexplained infertility and ICSI in the absence of semen abnormalities are two examples of this gradual technology creep. More in-depth economic analyses in the field of infertility are undoubtedly warranted. However, performing these analyses is challenging because infertility care poses a number of unique challenges. Studies of cost-effectiveness are open to criticism because there is a lack of consensus about the outcomes of choice and the appropriate perspective. The use of quality adjusted life years (QALYs) to allow comparisons with other clinical conditions is also controversial because the value associated with infertility care cannot be easily captured in QALYs. Moreover, their use triggers the crucial question of whose QALYs merit consideration-an individual's, a couple's or a child's. In conclusion, economic analysis in infertility represents a peculiar but crucial challenge. If management of infertility is to become an integral part of publicly or privately funded health care systems worldwide, better quality data and a shared vision about the costs and benefits of infertility treatments are needed.

The fifth report of the ESHRE PGD Consortium is presented (data collection V). For the first time, the cycle data were collected for one calendar year (2002) in the following October, so that data collection was complete for pregnancies and babies. The data were collected using a Filemaker Pro database and divided into referrals, cycles, pregnancies and babies. There are currently 66 active centres registered with the consortium; however, the data presented here were obtained from 43 centres and included 1603 referrals, 2219 cycles, 485 pregnancies and 382 babies born. The cycle data were divided into preimplantation genetic diagnosis (PGD) for inherited disorders (including chromosome abnormalities, sexing for X-linked disease and monogenic disorders), aneuploidy screening (PGS) and the use of PGD for social sexing. Data collection V is compared with the previous cumulative data collection (I-IV), which comprised 4058 PGD/PGS cycles that reached oocyte retrieval.