Parenting: Pregnancy

The screening is done 16 to 18 weeks after the last menstrual period. The test is routine and poses no threat to mother or baby. Blood is drawn from the mother's arm and sent to a laboratory for testing. Results are normally available in one week, depending on the laboratory used.

Maternal serum Alpha-fetoprotein (MSAFP) is produced by the liver of the fetus and enters the mother's bloodstream. Elevated levels of MSAFP may mean a neural tube defect or absence of all or part of fetal brain material, otherwise known as anencephaly. Triple screening can diagnose a high percentage of anencephaly and spina bifida cases. A low level of MSAFP could be an indication of Down syndrome; however, an AFP screen is not as accurate as an amniocentesis or chorionic villus sampling (CVS) in detecting Down syndrome, according to R. Harold Holbrook, Jr., M.D. of Stanford University. Only an amniocentesis or CVS screen can definitely diagnose or exclude Down syndrome. An AFP test can show a risk of an abnormality, not a diagnosis.

On a happy note, an elevated MSAFP level could also mean twins have been conceived, according to the Inland Northwest Regional Perinatal Center. A miscalculated due date can cause an elevated level, too.

Additional testing is performed in the event of an abnormal AFP test result and genetic counseling is available for the parents. According to the Cleveland Clinic Health Information Center, for every 1,000 mothers tested, 25 will have an abnormal test result. However, out of those same 25 abnormal results, only one or two will have a confirmed result of an abnormal fetus after further testing is completed. Even with those statistics, an abnormal test result can bring panic and anxiety to an expecting couple.

Dr. Jacob Canick is the lab director at the division of prenatal and special testing for the department of pathology at Women & Infants Hospital of Rhode Island. The facility is the primary teaching affiliate of the Brown University School of Medicine for obstetrics, gynecology and newborn pediatrics. Canick explains that the AFP3 test is a triple-marker test, checking the protein hormones AFP, estriol and HCG. He and his team of researchers have developed a four-marker test, the AFP Quad test, which can also detect high levels of a fourth protein hormone called Inhibin A.

"Inhibin A and HCG protein hormone levels tend to be high and ASP and estriol protein hormone levels tend to be low in the event of a fetus with Down syndrome," Canick says. Please note that although the new ability to check this fourth hormone increases the accuracy of the test, an abnormal result may not be a sure sign of fetal abnormalities. The AFP Quad test is not yet available in all areas.

Steve and Marian King from Long Beach, Calif., were delighted to find out that they were expecting their third child. The good news came at a difficult time for the couple. Marian's mother was terminally ill and Marian spent the first several weeks of her pregnancy at her mother's bedside.

The couple received an abnormal AFP test result two weeks after Marian's mother passed away. Marian and Steve were referred to a genetic counselor and were fortunate enough to get an appointment the very next day. The plan was that the counselor would meet with Marian and Steve for an hour, then an ultrasound would be performed to view the fetus. Within a few moments into the ultrasound, Steve asked, "Do I see two heads?" Five months later, Marian gave birth to healthy twin boys.