When fertility centers dispose of embryos, how should this be done? Current regulatory guidelines by the Human Fertilisation and Embryology Authority state that, when terminating the development of human embryos, a clinic should act with sensitivity, taking account of the embryo’s “special status” and respecting the interests of the gamete providers and recipients. As yet, it is unclear as to how and to what extent this achieved within fertility clinics in the UK. Resultantly, this paper examines the largely undocumented domain of embryo disposal practice. By undertaking an empirical study into policy and procedure and noting divergence in clinic practice, it then comments on the ethical implications of these protocols for patients and practitioners. Specifically, this paper argues for a more holistic approach to embryo disposal. An approach that effectively meets the requirements of the lab, is respectful of the “special status” of the human embryo, and, perhaps most importantly, reflects the multifaceted needs of the patient.

The objective of this study was to compare the rates of clinical pregnancy after the transfer of vitrified and thawed human embryos on days 3, 4 and 5 of embryonic development. In this retrospective study, the results of 148 embryo transfer cycles, using embryos frozen and thawed over the 3-year period between January 2016 and December 2018 at the Gülhane Training and Research Hospital Department of Gynecology and Obsterics Reproductive Medical Center of the University of Health Sciences, Ankara, Turkey were examined. Following embryo transfer – including 29 dissolved embryos frozen on day 3, 80 frozen on day 4, and 39 frozen on day 5 – results were examined in terms of clinical pregnancy rates. In this study, across all three groups, no significant differences were observed in terms of patient age, the number of oocytes collected, infertility reasons, the number of embryos dissolved, transfer day, or the number of embryos transferred. According to the transfer day, the rates of clinical pregnancy and ongoing pregnancy were significantly higher for embryos frozen on day 4 and transferred on day 5. Significantly higher rates of pregnancy and live birth were determined during in vitro fertilization (IVF) treatment with the freezing of human embryos on day 4 and the transfer of those embryos on day 5.

In general, solitary right aortic arch carries the left-sided ductus arteriosus communicating between the left subclavian and pulmonary arteries or the right-sided ductus connecting the descending aorta to the left pulmonary artery. Serial sections of fifteen 5- to 6-week-old embryos and ten 8- to 9-week-old fetuses suggested that the pathogenesis was unrelated to inversion due to dysfunction in gene cascades that control the systemic left/right axis. With inversion, conversely, the ductus or the sixth pharyngeal arch artery should connect to the right pulmonary artery. The disappearance of the right aortic arch started before the caudal migration of the aortic attachment of the ductus. Sympathetic nerve ganglia developed immediately posterior to both aortae, with a single embryonic specimen showing a large ganglion at the midline close to the union of the aortic arches. These ganglia may interfere with blood flow through the distal left arch, resulting in the ductus ending at the descending aorta behind the oesophagus. In another fetus examined, a midline shift of the ductus course resulted in the trachea curving posteriorly. Therefore, solitary right arch is likely to accompany abnormalities of the surrounding structures. The timing and site of the obstruction should be different between types: an almost midline obstruction near the aortic union needed for the development of the left-sided ductus and a distal obstruction near the left subclavian arterial origin needed for the development of the right-sided ductus. A mass effect of the sympathetic ganglia may explain the pathogenesis of any type of anomalous ductus arteriosus shown in previous reports of the solitary right arch.

This study aimed to investigate the optimum number of embryos to be biopsied in order to increase the likelihood of obtaining a balanced/normal embryo following preimplantation genetic diagnosis (PGD) by fluorescence in situ hybridisation (FISH) for translocation carriers. Patients with low number of fertilised oocytes (≤5) or low number of embryos available for PGD (<7) underwent multiple hormonal stimulation cycles and their embryos from each cycle were vitrified and accumulated to obtain at least three embryos for PGD. Fifty-seven PGD cycles were performed for translocation carriers by FISH on day 3 of embryo development. PGD and pregnancy outcomes were examined according to the number of embryos biopsied. The cancellation rates of embryo transfer for the reciprocal translocation carriers were 40% when more than eight embryos were biopsied and it was as high as 78% when low number of embryos (less than nine) were biopsied. For Robertsonian translocation carriers, when more than eight embryos were biopsied, there were no embryo transfer cancellations. This study showed that when there are more than nine embryos biopsied for PGD, the likelihood of obtaining a balanced embryo and positive pregnancy outcome is significantly higher (P < 0.05) in such the overall pregnancy rate was 63% for reciprocal and 86% for Robertsonian carriers. This was reduced to only 7% for reciprocal and 14% for Robertsonian translocation carriers when less than nine embryos were biopsied. One of the limitations of this study was that the analysis was performed by FISH and more studies should investigate the outcomes of embryo accumulation following comprehensive chromosome analysis.

Balanced reciprocal translocation carriers are usually phenotypically normal. Although the reproductive risk of these carriers varies, they generally have a lower chance to produce normal or balanced gametes. Preimplantation genetic diagnosis (PGD) is offered to these patients to increase their chances of becoming pregnant by selecting a balanced embryo for transfer. This study aimed to analyse the development and the PGD outcome of the embryos obtained from reciprocal translocation carriers focusing on ones with chromosome 10 rearrangements. In total, 27 reciprocal translocation carriers underwent 31 cycles of PGD. PGD was performed using multicolour fluorescence in situ hybridisation for 298 embryos and of these 136 were obtained from couples carrying translocations involving chromosome 10 rearrangements. Carriers of translocations involving chromosome 10 rearrangements have a lower chance of producing normal or balanced embryos compared with the carriers with other rearrangements. The development of embryos obtained from the patients with chromosome 10 rearrangements was impaired and only a limited number of embryos developed to the blastocyst stage.