AFP Test

AFP Test or Alpha-fetoprotein test is conducted on pregnant women to check the AFP level in the blood. The liver in the fetus produces AFP naturally. Determining the amount of AFP in the mother's blood will help identify any neural tube defect in the fetus. Neural tube defects arise in 2 out of every 1,000 pregnancies. AFP test also helps check for Down's syndrome. There are 60% chances for detecting Down's syndrome when the AFP levels are low in the blood. AFP can also be calculated from the sample of amniotic fluid of a pregnant woman. This screening test is generally performed between 16 and 18 weeks of pregnancy and is very sensitive between 15 and 17 weeks. The accuracy of the AFP test result lies in the exact age of the fetus. The AFT test is also referred to as maternal serum alpha-fetoprotein (MSAFP). AFP test is done on men and non-pregnant women too to confirm cancer in the testicles, stomach, pancreas, liver and the ovaries. High levels of AFP can indicate renal cell cancer.

Interpretation of AFP test results: In men and non-pregnant women, the values of the AFP test is 0-6.4 IU/mL (international units per milliliter), 0-20 nanograms per milliliter (ng/mL) or 0-20 micrograms per liter. In pregnant women of about 15 - 22 weeks gestation, the AFP results usually show 19-75 IU/mL, 7-124 ng/mL or 7-124 microgram per liter. AFP test values vary depending on the weight of the woman and race. Black women have higher values than white women and white women have higher values than Asian women. High AFP can suggest multiple pregnancies, fetus with neural tube defects, and abdominal wall defect in the fetus or fetal death. In non-pregnant adults, high AFP values mean cancer in the testicles or ovaries. High AFP can also indicate liver disease and bowel inflammation.

Anencephaly

Anencephaly is a rare birth defect in which major parts of the brain, scalp and skull of the fetus fail to develop completely. Anencephaly is a type of neural tube defect wherein the neural tube which is flat initially and later folds and closes together to form a tube, fails to close.

Infants with Anencephaly are born without cerebrum or cerebellum responsible for thinking and coordination. However they do have brain stem that allows them to breathe and their hearts to beat. Whatever brain tissue that develops, often is not covered by bone or skin. Babies born with Anencephaly are often still born or die within few hours or days of birth.

The exact causes of Anencephaly are not known. However it is proven that the deficiency of folic acid prior to and during pregnancy may increase the chances of neural tube defects. Pregnant women taking certain prescription drugs for diabetes and anti depressants are also at higher risk of giving birth to anencephalic babies. Some of the other factors that may put the expectant mother at risk are environmental pollution, exposure to household chemicals especially those containing teratogens substances, or other toxins. Anencephaly does not run in families; it results from a combination of genes inherited from both sides coupled with environmental factors.

Symptoms

Newborns with Anencephaly are born without bony covering over the back of the head and also around the front and sides of the head. Their ears are normally folded and their mouth has a cleft palate. Due to the absence of cerebrum, the baby stays in a vegetative state.

Diagnosis

Anencephaly is diagnosed as early as at 11-14th week of pregnancy, with certainty by performing ultrasound scan. The condition is also suspected when a pregnant mother's serum test reveals elevated alphafetoprotein (AFP)levels. Higher levels of AFP are only indicative of neural tube diseases, but does not in any way, confirm the condition. Hence further tests such as amniocentesis along with high definition ultrasound are ordered to confirm the condition.

If the prenatal test, for any reason, is missed and the fetus survives the term, the very appearance of the infant allows the medical team to diagnose Anencephaly. A large portion of the skull of the infant will be absent and the scalp, which extends to the margin of the bone will also be missing with no recognizable cerebral hemispheres. Often acrania is another similar condition which is confused with Anencephaly.

Treatment

There is no cure or treatment available for Anencephaly. These babies do not have chances of survival beyond few hours or days. Parents may require counseling services to cope up with the loss of their child.

Genetic testing

Genetic testing is a method of genetic diagnosis to check for the susceptibility to hereditary diseases and can also be used to establish the ancestry of any person. Genetic testing studies the chromosome, breaking it to individual genes. In a broader sense, it can be used as a biochemical test for scrutinizing the existence and nonexistence of main proteins that hint abnormalities of certain genes. Genetic testing studies the abnormality in the chromosomes, genes or proteins. It can be used to find out whether a particular genetic condition is developing and it's chances of being passed over to the future generations.

The most widely used type of genetic testing is newborn screening. Genetic testing during pregnancies is called as prenatal genetic testing and is performed during pregnancy to screen or identify birth defects. This provides ample information on the developing fetus both for the parents and the physician. Amniocentesis and chorionic villus sampling is the common diagnostic test performed to diagnose any defect in the fetus. These diagnostic tests are ordered for if the triple test (AFP test, hCG blood test, and UE3) returns abnormal results.