BUN study results

NORMAL! No amniocentesis for me.

1 in 1,200 for Down's
1 in 10,000 for something else I don't even know how to spell

More information about the BUN study:

Cedars-Sinai's Department of Obstetrics and Gynecology has served as the Los Angeles area's training and quality assurance center since the BUN study was started last year. Lawrence D. Platt, M.D., a specialist in maternal-fetal medicine and prenatal diagnosis, and chairman of the Department of Obstetrics and Gynecology, is the trial's principal investigator at Cedars-Sinai.

"Having one of the pioneers of these studies on board adds even more depth to a staff that is nationally recognized for its size and leadership in research in first-trimester screening. For our patients, the arrival of Dr. Snijders means greater experience and opportunity," said Dr. Platt, who also serves as president of the American Institute of Ultrasound in Medicine and is one of the world's most respected authorities on ultrasound and the development of three-dimensional ultrasound imaging.

The BUN study screens women for several factors that together appear to indicate whether a fetus is at high risk for a chromosomal abnormality, particularly Down syndrome. The result of the genetic defect that creates an extra copy of chromosome 21, Down syndrome is the most common chromosome anomaly, comprising about 50 percent of all chromosomally abnormal babies. The level of risk is determined by looking at two proteins in the mother's blood, the thickness of the skin on the baby's neck, and the mother's age.

Specifically, the two blood proteins that have been found to be indicators of risk are called "free beta human chorionic gonadotropin" (hCG) and "pregnancy associated plasma protein A" (PAPP-A). If hCG is present in the mother's blood in high concentrations, and PAPP-A is low, the baby is considered to be at high risk.

It also has been found that fetuses with Down syndrome and other abnormalities tend to have an excess of skin at the back of the neck, which can now be visualized by ultrasonography in the first trimester. Risk also increases with advanced maternal age. While first-trimester screening can be performed on pregnant women of all ages, women who will be 35 or older at the time of delivery are especially encouraged to participate in the BUN study.

According to estimates, screening by maternal age and nuchal translucency now identifies more than 80 percent of fetuses with Down syndrome. When the maternal blood protein markers are taken into account, the detection rate may be as high as 90 percent.