Aurora magazine

Non-invasive prenatal screening is spreading more and more in Japan. Soon, the medical institutions authorized to perform fetal DNA tests will increase. The decision comes after an exponential increase in requests in the country, also in relation to the rise in the average age of the first pregnancy.

The non-invasive prenatal screening tests were introduced in Japan in 2013, but were immediately debated. The guidelines of the Japan Society of Obstetrics and Gynecology have restricted the use of these tests to a few facilities. In addition, tests can only be performed on women 35 years of age or older with a history of chromosomal abnormalities. However, the increase in demand has pushed many unauthorized structures to offer the test anyway.

The situation made it necessary to stop unauthorized testing, in favor of certified fetal DNA tests. For this reason, the Japan Society of Obstetrics and Gynecology has decided to expand the authorization to new medical institutions. The goal is to incorporate non-invasive prenatal screening tests into routine medical checks.

Since the introduction of fetal DNA tests in 2013, the increase in facilities offering this type of service has been limited. We started with 15 certified facilities all over Japan and reached 89 in 2017. Maybe too little for the requests of a whole country.

Source: japantimes.co.jp

The majority of women with high or medium risk choose non-invasive prenatal screening as a secondary test for trisomy 21. This is revealed by a study published online in the International Journal of Obstetrics and Gynaecology. According to the authors, the fetal DNA test would be used by most Chinese women to verify the data of the first test.

Dr. Yvonne Kwun Yue Cheng from the University of Hong Kong followed a group of women who underwent prenatal tests. The women involved were considered high or medium risk. All had a genetic test for the trisomies 13, 18 and 21 and for all the results had been positive.

The standard procedure provides that a positive genetic test result is followed by a confirmation test. In addition to the amniocentesis, the options also included a precise, completely non-invasive fetal DNA test. Women were also free to refuse further tests.

Of the 347 high-risk women, 99% chose to perform a further prenatal screening test. Of these 216 (62.2%) they chose the fetal DNA test. Among the 614 participants at medium risk, however, as many as 507 (82.6%) chose the fetal DNA test. Among the 34 women who performed nuchal translucency, 21% chose non-invasive prenatal screening as a second test.

In a context where response times and costs were similar, most women chose the non-invasive prenatal screening test. Nevertheless, according to doctors, the best combination remains a fetal DNA test followed by a possible amniocentesis.

Source: medicalxpress.com

In recent years, the non-invasive prenatal screening tests for Down's syndrome are gaining ground. According to a study by the Murdoch Children's Research Institute (MCRI), other genetic tests should be added to this widespread test.

Fetal DNA tests for prenatal diagnosis of Down syndrome are offered to all women over a certain age. In the case of other genetic diseases, however, it is thought that the problem concerns only those who have had cases in the family. Yet fragile X syndrome, spinal muscular atrophy and cystic fibrosis have a risk rate comparable to that of Down syndrome, if put together.

Genetic tests for the three hereditary genetic diseases have been available since 2012. They are usually recommended to those who already suspect they are healthy carriers. A way of acting that neglects a large part of the population, perhaps unaware of their family history. The principal author of the study, Professor David Amor, believes that these tests should be available for all couples wishing to make a child.

From the data collected it emerged that 1 in 20 people among those analyzed is the bearer of one of the three genetic diseases. 88% of these individuals were not aware of the risk, as they were not aware of any case in the family. So none of them would have carried out the genetic test, if it had not been involved in the test.

Among the couples analyzed, 1 in 240 presented a high risk of transmitting the disease to the offspring. In addition, prenatal screening tests revealed the presence of one of the diseases in about 1 pregnant woman in 1000. These are comparable to the incidence of Down syndrome.

Source: medicalxpress.com

The use of non-invasive prenatal screening tests is increasing year by year. So there are also concerns about the lack of understanding of these techniques, both by doctors and patients. For this reason, The Journal of Applied Laboratory Medicine has published an explanatory article on it. The goal is to provide doctors who follow the magazine all the information needed to reassure even the most anxious patients.

Thanks to a drop of maternal blood, a non-invasive prenatal screening test allows you to identify common genetic abnormalities. Down's syndrome and others are diagnostically diagnosed in the uterus without risk for either the mother or the baby. At first the test was recommended especially for high-risk pregnancies. More and more studies, however, show its utility in low-risk pregnancies.

In 2016, the American College of Obstetrics and Gynecologists renewed their guidelines. She now recommends that fetal DNA tests be tested on all women who are on hold, regardless of age. Despite its success, however, this technology is still not very well understood.

In the article, a team of experts from the University of Washington in Seattle explains how doctors should face the tests. Still too few people understand that non-invasive prenatal screening is just one element of diagnosis. If a negative result gives assurance that the fetus is healthy, it is not mathematical the opposite. If the test is successful, it is best to proceed with further analysis that confirms or deny the first result.

The authors also warn of the use of rare genetic testing. In these cases, it is best to proceed with caution. There are indeed many less studies on the effectiveness of these tests, rather than those applied to Down or Evans syndrome.

Source: aacc.org