Pregnancy Over 40 and Down Syndrome
Many women, especially those who are older in age, undergo some type of prenatal screening.For More On Pregnancy Over 40, Visit www.getpregnantover40.com
This article talks about some of the possible risks and the risk of false positives. It is even possible that normal pregnancies which test positive may end in termination, even when the fetus is normal. Read more:Needle test
A positive test at this point does not mean Down's is highly likely - in some cases, only one in 20 women who screen positive actually have an affected baby.
To confirm or rule it out, a further test is offered - either amniocentesis and chorionic villus sampling, both of which use a fine needle to take tissue or fluid from inside the womb.
However, the charity suggests that the risks linked to these invasive tests, and the high number carried out, lead to 400 miscarriages in pregnancies unaffected by Down's.
Some research suggests that the miscarriage rate following chorionic villus sampling may be as high as 2%, the researchers said, which, if true, would raise that toll closer to 600.
National guidelines now recommend a newer version of screening - the "combined test", which may be more accurate in predicting which women are at higher risk of carrying a baby with Down's.
However, the researchers said that despite a lower number of invasive tests, the heavier reliance of this method on chorionic villus sampling earlier in pregnancy could actually mean an increase in the number of healthy babies lost if the miscarriage rate using this method was closer to 2%.
from:
news.bbc.co.uk
