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.

hCG blood test

hCG blood test or pregnancy blood test measures the accurate amount of pregnancy hormone, human chorionic gonadotropin (hCG) in the bloodstream. Pregnancy hormone hCG is produced by the placenta. It can be assessed in the blood and urine of a woman within 10 days of fertilization. hCG can be measured by:

Quantitative pregnancy blood test: This test measures the accurate amount of hCG in the blood of a woman and plays a vital role in assessing the age of the fetus. This test also helps in checking if the pregnancy is developing normally.

Qualitative pregnancy blood test: This test can only tell if there is hCG present in the blood and can give no further information. This test result is like the home based pregnancy test kit just giving a 'yes' or 'no'.

In men and non pregnant women, the typical levels of hCG is less than 5 international units per liter (IU/L). In pregnant women, it is about 5 - 100 during 24 to 28 days after last menstrual period (LMP). During 4 to 5 weeks after the LMP, the hCG is about 50-500 IU/L and peaks to about 12,000 - 270,000 IU/L during 14 - 16 weeks of pregnancy. High levels of hCG can signify multiple pregnancy or molar pregnancy or Down's syndrome. In non-pregnant women and in men, it can signify cancerous or non-cancerous tumor of the testicles or ovaries. Low values of hCG in pregnant women can signify ectopic pregnancy, death of baby or that the pregnancy is not proceeding the way it has to. It can also indicate a spontaneous miscarriage.

Bone density test

Special x-rays are used to determine how many grams of bone mineral content (calcium and other bone minerals) is filled into a section of the bone. Bones with high mineral content indicate very dense bones thus indicating the bones are strong and have fewer chances of breakage. Bone density tests are recommended by doctors to check for osteoporosis. Bone density tests are done either by central or peripheral devices. Central devices are huge machines on which the patient can lie down. Such devices are mainly used to check the lumbar vertebrae (lower region of the spine), the narrow neck of the femur bone adjoining the hip and the bones of the wrist and the forearm.

Dual energy X-ray absorptiometry (DXA): This test produces exact results and is the most preferred choice to diagnose osteoporosis. The patient will be asked to lie down on a padded platform as an imager (an apparatus like a mechanical arm) passes above the body. The required information is captured by the device and the test is completed within 20 minutes. The amount of radiation exposure in this test is equal to one-tenth of a chest x-ray radiation. DXA scan can detect even a 1% change in the bone, that which can not be achieved through an ordinary x-ray.
Quantitative CT scan: The bone density (especially spine) is measured with the help of a computerized tomography (CT) scanner along with computer software. The scan produces a three-dimensional picture which also relates to the aging consequences of the bone and diseases other than osteoporosis. The patient is made to lie down on a movable table that is directed into a big tube-like area where images are pictured. The test is completed within 20 minutes and the radiation exposure is slightly more when compared to the DXA scan.

Peripheral devices are moveable machines that measure the bone density on the periphery of the skeleton. e.g. finger, wrist or heel. They are smaller machines when compared to the central devices and can be found in pharmacies and have their own restrictions. These machines are used to check for the bone density in the heel, or wrist or fingers.