After single embryo transfer thawed PGD does not affect pregnancy rates

Transfer of an embryo at a tme when, in a woman's uterus after the embryos were IVF (IPR) and gel in the blastocyst, a real option of pregnancy, researchers, prices were as good as blastocysts, the cell is not a PGD removed before freezing. The results mean that it will be possible to reduce the number of multiple pregnancies after the PID and the complications arising in the context of these pregnancies.

The research was at the 25th Annual Meeting of the European Society of Human Reproduction and Embryology in Amsterdam online and in Europe, the leading journal of reproductive medicine, human reproduction, at the same time today.

Dr. Yacoub Khalaf, director of design support single Guy's and St Thomas' Hospital, London (UK), the Conference said: "To our knowledge, our study is the first to obtain assurance that the strategy the elective single embryo transfer with a good prognosis, patients with PID, supported by a powerful PID cryoconservation service during pregnancy can have the effect that the prices are comparable to those of non-biopsy embryos by that in the conventional framework of fertility treatment. The results should enhance fertility centers for island cycles inherited genetic disruption of their efforts to reduce pregnancy rates following several different forms of design treatment. Given the growing frequency of PGD cycles performed each year, the great advantage of the application of this political. "

Until now, fertility specialists do not have a single embryo transfer for the PID for inherited genetic diseases, because of concerns about the way to biopsy embryos survive after freezing and thawing. "He felt that the impact of biopsy of the embryo" of zero tolerance limited. This concern is not about the science, but only on models of low survival rate of embryos frozen biopsy, "said Khalaf.

From January 2006 to July 2008 Dr. Khalaf and his colleagues suggest single embryo transfer, in conjunction with excess frozen blastocysts for couples, the PID for hereditary genetic disorders such as cystic fibrosis. All embryos were biopsy for PID, the third day after fertilization, which, it is time they begin to share. Healthy embryos were grown in the laboratory for more than two to three days to ensure, as far as achieving the next phase of development - the blastocyst stage. At this time, 32 couples with two or more embryos, the success of the blastocyst stage have been the possibility of the stomach and the rest of jelly. The researchers compared the outcomes of pregnancy by another 32 frozen-thawed PGD cycles in couples with pregnancy, the results of a couple, where conventional 191 cycles of IVF / ICSI were performed with frozen embryos and thawed before the implantation, biopsy, but not at every stage.

They found that the blastocyst survival after thawing was similar between PGD and IVF / ICSI-group (87% versus 88% respectively). There was no significant difference in implantation and clinical pregnancy rates (35% versus 29% and 34% versus 36% respectively). The entire course of pregnancy for all cycles of freezing (PGD and IVF / ICSI) was 34%, in comparison with the UK national average for frozen thin skirt of cycles (18% live birth rates per thaw ).

If, during the same period was compared to the period just before embryo transfer policy was the PID for couples of pregnancy in cycles of PGD fresh meat fell from 36% to 10 % free prices in the pregnancy.

Dr Khalaf said: "This indicates that the research, clinical decisions should not be at the expense of reducing the effectiveness of treatment. You can responsibilities and chances of success for your patients and clinical evaluation using the techniques.

"For patients, it is certain that the chance a couple, a healthy child, not reduced to a single blastocyst and freeze the surplus. Frozen blastocyst, which have a very good chance that a pregnancy healthy and, therefore, patients will not feel under pressure to have more than one embryo replaced (with the increased risk of multiple pregnancy), for the use of their biopsy, not embryos, Otherwise, they could very little use. Now, it is frozen blastocyst offers them the chance of a healthy pregnancy without you throughout the cycle. "

The first author paper in Human Reproduction, Dr. Tarek El-Toukhy, a consultant in reproductive medicine and the PID on supporting the unique design Guy's and St Thomas' Hospital, said: "This study is a continuation of efforts for the promotion of IVF and security only by PGD and blastocyst freezing of embryos "