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According to the largest study of babies born following the technique, taking an eighth of a developing embryo during IVF treatment to test for genetic diseases is “completely safe”.

Preimplantation genetic diagnosis (PGD) can help doctors spot diseases like cystic fibrosis before deciding whether to continue with fertility treatment.

However, there have been concerns about PGD’s safety.

Three days after an egg has been fertilized in an IVF clinic, the developing embryo would be made up of just eight cells.

It is at this stage that doctors can delicately remove one of those cells to test for more than 100 genetic diseases. If the embryo is given the all-clear, it can then be transferred into the woman’s womb.

Preimplantation genetic diagnosis (PGD) can help doctors spot diseases like cystic fibrosis before deciding whether to continue with fertility treatment

Preimplantation genetic diagnosis (PGD) can help doctors spot diseases like cystic fibrosis before deciding whether to continue with fertility treatment

PGD is rare, but the University Clinic in Brussels, Belgium, part of the Free University, performs about 600 PGD cycles every year.

Its data on 995 babies born through the technique between 1993 and 2008 was presented at the European Society for Human Reproduction and Embryology conference in Turkey.

It suggested the risks of low birth weight, premature birth, major malformations and the perinatal death rate was the same as for other forms of IVF.

Lead researcher Dr. Sonja Desmyttere said: “Embryo biopsy does not adversely affect the health of newborn PGD children.

“It is important for parents to know that PGD is a safe option.”

She advised prospective parents should “go for it,” but added that research was still taking place on the impact of the test later in life.

Other research on PGD presented at the conference suggested that testing for hereditary breast cancer was a “good” and “feasible” option for parents.

The genes BRCA1 and BRCA2 are known to hugely increase the risk of breast cancer. Women with one of these genes have a 60% to 80% chance of developing breast cancer in their lifetimes. There is also an increased risk of ovarian cancer.

The genes can be detected by PGD, meaning embryos could be selected that do not have a heightened risk of breast cancer.

Doctors at two large fertility clinics at university hospitals in Maastricht, in the Netherlands, and Brussels, have reported 42 pregnancies after screening for BRCA genes between 2006 and 2011.

Prof. William Verpoest, from the Vrije University in Brussels said: “We now believe that this technique offers an established option for those couples seeking to avoid the risk of inherited BRCA in their children.”

However, he admitted this “would never be a default option” for all couples with BRCA genes, as the procedure was ethically controversial.

 

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US researchers have used a blood sample from mother and saliva from father to sequence the genome of a foetus in the womb.

At the time, the mother was just 18 weeks into the pregnancy.

The doctors said the findings, reported in Science Translational Medicine, could eventually lead to foetuses being screened for thousands of genetic disorders in a single and safe test.

However, they also caution it would raise “many ethical questions”.

US researchers have used a blood sample from mother and saliva from father to sequence the genome of a foetus in the womb

US researchers have used a blood sample from mother and saliva from father to sequence the genome of a foetus in the womb

The scientists at the University of Washington used pieces of the foetus’ DNA which naturally float around in the pregnant woman’s blood.

These fragments were then pieced together using the parents’ DNA as a guide to build a complete “map” of the foetus’s genome.

They then compared the genetic map drawn 18 weeks into pregnancy with the foetus’ actual DNA taken from the umbilical cord after birth. It was 98% accurate.

The researchers hope their findings will one day be used to test safely for genetic diseases.

Tests do already exist such as those for Down’s syndrome. To test for Down’s syndrome a sample is taken from the sac around the developing foetus, which comes with a risk of miscarriage.

They also say new genetic defects, which are not present in the parents, could be picked up if the technique could be improved. Such mutations form in the eggs, sperm or at conception.

There were 44 new mutations in the foetus and the screen at 18 weeks found 39 of them. However, the screening also detected 25 million possible new mutations or false positives.

One of the researchers, Dr. Jay Shendure, said: “This work opens up the possibility that we will be able to scan the whole genome of the foetus for more than 3,000 single-gene disorders through a single, non-invasive test.”

 

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