Artificial insemination New method worked

Retort baby born according to new method in artificial insemination

08/07/2013

In England, the first baby born after artificial insemination was born in June, whose genome was known in advance. The embryo would have been sorted out if he had been ill.

Baby Connor
This morning, UK confirmed what experts have been predicting for months: the entire genome of artificial embryos can be fully deciphered before being transferred to the mother. British reproductive geneticist Dagan Welss of Oxford University announced this morning at the annual European Reproductive Medicine (ESHRE) conference in London that the first baby embryo to undergo this procedure was born in the US in June. The genetic material could already be read before the mother was even pregnant. The parents of the baby named Connor had tried in vain to get children for years. After all, the 36-year-old's pregnancy was successful after artificial insemination and selection of the genetically sound embryo.

Priced cheaper
The first tests with the so-called „Next Generation Sequencing“ (NGS) had been successfully applied by a team led by Wells of the Biomedical Research Center at Oxford University. „NGS provides unprecedented insights into the biology of embryos, "says Wells, adding that while traditional methods have a maximum success rate of 30 percent, it is believed that this may be due to hidden chromosome defects, although the reason for this is unknown. The new method, which should also be cheaper than previous methods, will now be tested in a larger scale study.

Decipher and analyze the entire genome
The new procedure has already been used by other couples. Thus, according to the British researchers, the birth of another baby is imminent, in which the genome was deciphered by the same method before transplanting it into the womb. The new test procedure is a further development of preimplantation genetic diagnosis (PID). This is used to target embryos for specific genetic diseases before they are used for artificial insemination. For this purpose, individual cells are removed from the embryo and genes in the genetic material of the cells are individually tested for defects. It is usually about defects that are only on one gene, the monogenic hereditary diseases. If a parent is suspected of having an inherited disease, then embryos can be tested. Thanks to further development, the scientists are now able to decipher and analyze the entire genome from the tiny amount of genetic material from two or three cells of the embryo.

„Baby-take-home rate“
At present, scientists around Wells are not concerned with complete genome decoding, but the aim is to achieve a particularly high pregnancy rate during IVF treatment so that patients are spared repeated cycles of treatment and hormone administration. For IVF (in vitro fertilization - Latin for „Fertilization in the glass“) is an artificial insemination, which is used since 1978 in the treatment of unmet need for children. Since then, three million children have been born worldwide using test tube fertilization. In Germany the costs are partly taken over by the health insurance companies. The rate of successful births after artificial insemination is considered by reproductive physicians as „Baby-take-home rate“ designated.

Pregnancy rates of at least 70 percent
In the new procedure, the scientists read the genetic molecules only superficially to determine a possible chromosome disorder (aneuploidy) of the embryo. That would be the case if the cells do not have the correct number of 46 chromosomes. Missing (monodomies) or supernumerary (trisomies) chromosomes are considered the cause of the failure of the pregnancy treatment. Such deviations carry the very high risk that the embryo is not viable or leads to a miscarriage. For example, in trisomy 21, the cause of Down's syndrome, about two thirds of affected fetuses die in the womb. The IVF physicians achieve in the first attempt pregnancy rates of at least 70 percent according to the experience with the chromosome tests. Regardless of the age of the women, the success rate remains stable.

German legal situation unclear
Among lawyers is disputed whether the new method in Germany would be allowed under the PID law. Only recently, after years of political and ethical conflict, Parliament had allowed the introduction of PGD, but within narrow limits and on the assumption that hardly more than 200 such investigations would be conducted annually. However, if the new method were to become a routine fertility treatment, tens of thousands of embryo tests would be performed annually. The majority would not pass this and be sorted out in the lab before nature does. Klaus Diedrich, chairman of the PID Commission at the German Society for Gynecology and Obstetrics, considers it unlikely that the method will be introduced in Germany: „In the UK, the screening was conducted only on suspicion, which is unthinkable in Germany. "(Ad)