Description
During pregnancy, foetal AFP reaches maternal circulation through the placenta and peaks at week 13 of gestation after which AFP level rapidly declines until term. Maternal AFP is used to screen for foetal abnormalities; if the foetus has an open neural tube, AFP leaks into the amniotic fluid and causes an increase in amniotic fluid AFP level which causes maternal AFP level to rise.
Indications
Altered AFP levels have been observed concurrent with aberrant growth manifestations. Maternal AFP is used to assess the risk of carrying a fetus with open neural tube defect. Maternal AFP is also increased in cases of omphalocele, gastroschisis, defective kidneys, and fetal demise and is normally increased in multiple pregnancies (twins). Decreased levels are seen in molar pregnancy, missed abortion, pseudocyesis and Down's syndrome. AFP measurement can be performed alone or in combination with "β-HCG and / or FE3. If in combination with "β-HCG and FE3, the test is called a Prenatal Interpretive Screen and is usually performed between weeks 15 and 20 of pregnancy to assess the risk of carrying a foetus with open neural tube defect or Down's syndrome.
Sample Type, Quantity & Conditions
1 ml Serum 1 ml Na2, K2-EDTA or Li, Na-Heparin Plasma Stability: 3 Days at Room Temperature 7 Days at 2-8 °C > 7 Days at -20 °C
Special Precautions
Collect sample between 15-20 weeks of gestation. Provide the following information: Gestational age of mother on date of sample collection. Weight and date of birth of mother & relevant patient history. Specimen must be collected before amniocentesis.
Normal Range
ng/mL Dependent on Gestational Age, See Report
