New Prenatal Test Promises a Safer Way To Detect Abnormalities

A groundbreaking new blood test promises to isolate potential genetic defects as early as the 9th week of pregnancy -without any risk to mother or baby. Here's what you need to know.


By Colette Bouchez

If a group of Hong Kong doctors are right, it may now be possible to map out an unborn baby’s entire genetic blueprint using just one tube of the mother’s blood – and do it  as early as the 9^th week of pregnancy. 

That’s the hope for  a brand new  blood test that promises to give parents the information they need about the health of their unborn baby, without the need for invasive testing that carries a risk of miscarriage. 

Indeed,  at present the most common way to detect a fetal abnormality is a procedure known as amniocentesis. In  this test –  usually performed between the 15^th and 20^th week of pregnancy – doctors insert  a needle into the mother’s abdomen to extract samples of the amniotic fluid surrounding the baby in the uterus. By testing this fluid doctors are able to map out an array of potential genetic birth defects.

While the test works exceedingly well, it is not without it’s drawbacks – the most serious of which is a 1% risk of miscarriage . This procedure-induced pregnancy loss becomes even more overwhelming when the parents learn that the test results are normal – and their baby would have been normal as well. 

But now a   team of scientists from the Chinese University in Hong Kong promise to do away with any risk of that heartbreak by using the new non-invasive blood test to detect  the same problems as an amniocentesis, without any risk to mother or baby.  And, to do so as early as the 9^th week of pregnancy.

In the past  looking for genetic disorders via a blood test was a long and laborious process requiring a separate set of parameters for each individual disorder.  This was because doctors believed only isolated portions of a baby’s DNA were present in the mother’s blood.

Now however, the Hong Kong doctors say their groundbreaking discovery  reveals that  the entire genetic blueprint for each child is present in a single sample of a mother’s blood. This , they say, opens the door to detecting an entire  range of genetic abnormalities -   including the most common  forms of anemia known as alpha and beta thelassaemia, as well as cystic fibrosis  - with a single, non -invasive test.

 Dennis Lo Yuk-ming, who led the research, told the Deutsche Presse –Agentur that the process of teasing out all the elements to make the test work was on the order of “assembling a jigsaw containing a million pieces.”

So how did they do it?  The new  blood test works, say experts, by first isolating the chromosomes inherited from the father, and then locating the rest of the baby’s DNA by looking for differences in the level of gene concentration in the mother’s blood –indicating which genes the baby inherited. 

Together, these two pieces of information  form the  genetic blueprint of the unborn child. 

While the blood test is indeed promising,  presently it’s very costly. The researchers say their  next step is to bring the cost down, which the scientists believe is entirely possible by reducing the search to include only  the most common genetic defects.  The new, more affordable  test could become available worldwide  as early as the coming year.  

For more information on ways to prevent the risk of birth defects related to miscarriage visit Green Fertility.com – or pick up a copy of Green Fertility – Nature’s Secrets for Making Babies.

 Copyright by Colette Bouchez 2010 - All Rights Reserved. In addition to US Copyright, the text of this FERTILITY BLOG is licensed under a Creative Commons Attribution 3.0 License. All Formatting and style elements of this page are not available under this license and Colette Bouchez retains all rights in those elements.  The creators and authors of this blog may or may  not benefit from the mention of products or services featured in these pages.