Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Is the test - tube conception dangerous?

The number of “infants from a test-tube” is growing year by year, and in highly developed countries it will soon make 1% to 3% of all new-borns.

But how safe are the auxiliary reproductive technologies (ART)? Having summarized the data accumulated by the world science, specialists of the Research Institute of Medical Genetics (Tomsk Scientific Center, Siberian Branch, Russian Academy of Medical Sciences) tried to look into only one aspect of the ART safety – risk of genomic imprinting diseases.

What kind of diseases are they? Normal mammal development requires that maternal and paternal gene sets differed functionally. In certain genes, only the maternal copy should work. And in others – only the paternal copy should. The mechanism regulating functional differences of parental genomes is called genomic imprinting. This is a complicated and multi-step process, which starts in the parental gametal cells, where special enzymes mark and disconnect the required genes (a human being has about 70 of them), and continues after impregnation. Heavy pathologies can be caused by failure of such marking at some stage, and several genomic imprinting diseases are known with human beings.

Genomic imprinting reacts to external factors, and the researchers expected that the auxiliary reproductive technologies could influence it. The first example of such influence was discovered in experiments on animals’ artificial impregnation. The “large posterity syndrome” sometimes develops with big horned cattle and sheep after embryo cultivation, the posterity weight often by twice exceeding the norm. Another important indication is increased fetus mortality in the course of pregnancy and in labour, at that the pregnancy is long and the delivery is difficult. The deceased fetus and new-borns have internal pathologies. The “large posterity syndrome” caused by derangements of genomic imprinting is very similar on the surface to the Wideman-Beckwith human syndrome arising for the same reason. In case of the Wideman-Beckwith syndrome, infants are born very big and with multiple pathologies. The syndrome frequency is normally one case per 12 to 15 thousand of new-borns, but it is several times higher with the children born with the help of the ART.

The researchers suggest several hypotheses explaining why genomic imprinting diseases occur more often in case of the ART than in case of traditional conception. Firstly, the process may be influenced by methodical peculiarities of artificial impregnation. In case of extracorporal fertilization, women are injected hormones to stimulate the ovulation. Possibly, gonadotropins accelerate maturation of ovums, which have not finished yet the genomic imprinting process. In some cases ovums have to be cultivated in nutrient medium prior to fertilization, and after fertilization embryos are bred on it before transplanting in the maternal organism. The nutrient medium composition and the lack of signals coming from the maternal organism in a normal case can also impact genomic imprinting, which takes place both in maturing ovums and in the developing embryo. It is not improbable that the genome marking can be influenced by cryopreservation of gametal cells and embryos, which is often practiced.

Secondly, the ART enables the events that would have never happen in a natural way. Thus, “anomalous” ovums can mature in case of hormone stimulation, such ovums would have scarcely mature during a natural cycle. Spermatozoa also can have imprinting defects. Normally, their fertility is low but they can be used for artificial impregnation, and then trouble is inevitable. Finally, artificial impregnation makes it possible that ill children are born with infertile married couples who have predisposition to genomic imprinting diseases.

Now, there is no unanimous opinion among the researchers as regards to the ART and genomic imprinting diseases. Some assume that the birth “the test-tube” children is an extremely rare event and it cannot be the reason for rejection of artificial impregnation. Their opponents believe that the genomic imprinting abnormalities cases known to us make only the visible part of the iceberg. We do not know too many things, and the risk of giving birth to infants with imprinting defects is although little, but important. Therefore, it is necessary to investigate the problem and to make extracorporal fertilization safe in every respect.

Nadezda Markina | alfa
Further information:

More articles from Health and Medicine:

nachricht NIH scientists describe potential antibody treatment for multidrug-resistant K. pneumoniae
14.03.2018 | NIH/National Institute of Allergy and Infectious Diseases

nachricht Researchers identify key step in viral replication
13.03.2018 | University of Pittsburgh Schools of the Health Sciences

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

TRAPPIST-1 planets provide clues to the nature of habitable worlds

21.03.2018 | Physics and Astronomy

The search for dark matter widens

21.03.2018 | Materials Sciences

Natural enemies reduce pesticide use

21.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>