Pregnant women have the option of having a series of blood tests performed called maternal serum screenings. These screenings can help identify certain anomalies such as spinabifida, down syndrome, or trisomy 18. A blood sample is taken and the screenings pose no threat to the fetus. Down syndrome and spinabifida are not rare medical conditions. Approximately 1 in every 650 live births is a child with down syndrome and 1 in every 750 live births is a child with spinabifida.
The alpha-fetoprotein, or AFP, is one of blood tests performed. It measures the amount of AFP in the mother's blood. In down syndrome the amount of AFP tends to be lower than normal. In spinabifida, the amount of AFP in the mother's blood tends to be higher than normal. Screenings such as the AFP are not always accurate and are known to return "false positives."If an AFP indicates that the fetus may have an anomaly, doctors will recommend an amniocentesis.
Amniocentesis is a much more accurate diagnostic test considered to be 99% accurate. Amniocentesis is usually done between the 14th and 18th week of pregnancy. It is not recommended prior to the 14th week because of the increased risk of miscarriage. Amniocentesis is controversial because when done during the appropriate time, it increases the risk of miscarriage an additional 1/2 to 1%. Amniocentesis is also controversial because 80% of women who choose to have an amniocentesis and find it is positive for an anomaly opt for abortion. Amniocentesis results typically take 2 weeks to be returned, so most expecting parents get amniocentesis results in the 16th to 20th week of pregnancy.
If amniocentesis is refused, there are additional markers that can be identified on an ultrasound to help diagnose genetic anomalies without posing risk to the fetus. Like maternal serum screenings, ultrasound markers are not always accurate, but the two can be used in combination to help determine the risk of a fetal anomaly.
 | Prenatal testing is a routine part of care that allows your doctor to treat any conditions that might harm your developing baby. Learn what they look for and what tests to expect. |
 | Amniocentesis is a test that screens for a variety of genetic and developmental disorders in the womb. Since it is an invasive procedure, there are slight risks of injury to both mother and child. |
Heartburn and pregnancy go hand in hand. For many moms-to-be, heartburn kicks up during the first trimester and tends to get worse in the second and third trimesters. |
 | Pregnancy ultrasound is a safe test that can help to determine the health of your baby. It can also serve as an early warning system for any abnormalities. |
Down Syndrome screening isn't like tests that produce a yes or no result; it only indicates the potential for the condition, and says little about the symptoms a child will have. |
