DNA Testing Coupons

Why is amniocentesis or CVS is preferred over PUBS even though it gives more detailed results?

PUBS is also known as Percutaneous Umbilical Blood Sampling which examines fetal blood directly from the umbilical cord and uses that sample to detect the disorder. This method is used to detect many kinds of genetic disorders that the unborn child might have, and can also tell about certain blood conditions or infections but, even so, other tests like CVS & Amniocentesis DNA Tests are preferred over this test. In PUBS the sample is obtained by use of an ultrasound. The doctor uses ultrasound to detect the umbilical cord and then with the guidance of the ultrasound inserts a needle...