Gestational dating ultrasound
When there are sufficient numbers of dividing cells the specimen is removed from the incubator and the placental cells are split open with an enzyme.The individual chromosomes are counted and analysed. As every pair is analysed, the results not only indicate the presence or absence of an extra chromosome number 21(Down Syndrome), but excludes chromosome abnormalities in the other 22 chromosome pairs.It can, however, be performed at any time throughout the remainder of the pregnancy.What preparation is required prior to the procedure?This can help make the uterus more accessible for the needle test. The specimen is sent to a laboratory to be processed.
The individual bands of each chromosome are examined in great detail for subtle genetic abnormalities such as This test excludes not only Down syndrome, but a wide variety of subtle and major chromosome abnormalities. It is advisable for someone to take you home after the test and that you rest for the remainder of the day.If the sex chromosome option is ordered, results will be reported as either low or high probability.If gender is requested this will be labelled as male or female.Most patients find the examination much more tolerable when compared to a cervical PAP smear.During the scan the sonographer may need to gently press on the abdomen to move bowel out of the way and bring the ovaries and other pelvic structures into view.