Search results
Results from the WOW.Com Content Network
AFP is normally elevated in infants, and because teratoma is the single most common kind of tumor in infants, several studies have provided reference ranges for AFP in normal infants. [5] [6] [7] Perhaps the most useful is this equation: log Y = 7.397 - 2.622.log (X + 10), where X = age in days and Y = AFP level in nanograms per milliliter. [8]
As an example, Alpha-fetoprotein (AFP) testing is used to screen for a neural tube defect (NTD) during the second trimester of pregnancy. If the median AFP result at 16 weeks of gestation is 30 ng/mL and a pregnant woman's AFP result at that same gestational age is 60 ng/mL, then her MoM is equal to 60/30 = 2.0.
The normal range of AFP for adults and children is variously reported as under 50, under 10, or under 5 ng/mL. [ 21 ] [ 22 ] At birth, normal infants have AFP levels four or more orders of magnitude above this normal range, that decreases to a normal range over the first year of life.
In adults a normal amount of AFP is 0-40nng/mL and high levels of this can indicate diseases, cancer, and fetal defects. In pregnant people AFP levels rise at 14 weeks until 32 weeks, and range between 10 and 150 ng/mL in the middle of gestation. This is why AFP can be used alongside other tests as a tumor marker protein in adults. [12]
The most common abnormality the test can screen is trisomy 21 (Down syndrome).In addition to Down syndrome, the triple and quadruple screens assess risk for fetal trisomy 18 also known as Edwards syndrome, open neural tube defects, and may also detect an increased risk of Turner syndrome, triploidy, trisomy 16 mosaicism, fetal death, Smith–Lemli–Opitz syndrome, and steroid sulfatase ...
Second-trimester maternal serum screening (AFP screening, triple screen, quad screen, or penta screen) can check levels of alpha fetoprotein, β-hCG, inhibin-A, estriol, and h-hCG (hyperglycosolated hCG) in the woman's serum. The triple test measures serum levels of AFP, estriol, and beta-hCG, with a 70% sensitivity and 5% false-positive rate.
Reference ranges (reference intervals) for blood tests are sets of values used by a health professional to interpret a set of medical test results from blood samples. Reference ranges for blood tests are studied within the field of clinical chemistry (also known as "clinical biochemistry", "chemical pathology" or "pure blood chemistry"), the ...
Cell-free fetal DNA (cffDNA) is fetal DNA that circulates freely in the maternal blood.Maternal blood is sampled by venipuncture.Analysis of cffDNA is a method of non-invasive prenatal diagnosis frequently ordered for pregnant women of advanced age.