Analysis of AFP in pregnancy: when to do and why?
Analysis of AFP in pregnancy is necessary for determining chromosomal abnormalities of fetal development, pathologies of internal organs, defects in the development of the nerve channel. The optimal period for the analysis of alpha-fetoprotein is the interval between the 12th and 20th weeks, the ideal period is 14-15 weeks.
What can AFP analysis signal during pregnancy?
According to the international system of standards, the designation of abnormalities in AFP is measured in MoM (multiples of median-fold median), which indicates the mean values ??corresponding to this term of pregnancy. Normal values ??are from 0, 5 to 2, 5 MoM, and if the AFP levels deviate from the norm in one direction or the other, this may indicate problems in fetal development:
Excess AFP in pregnancy:
- multiple pregnancy;
- improperly defined gestational age;
- malformation of the neural tube;
- kidney pathology;
- liver necrosis;
- umbilical hernia of the fetus;
- non-growth of the anterior abdominal wall of the fetus
- other malformations of the fetus.
Decreased AFP level during pregnancy:
- retarded fetal development;
- Down syndrome;
- Trisomy 18;
- other chromosomal abnormalities;
- probability of miscarriage, death of the fetus;
- bubble skidding.
Adverse AFP analysis in pregnancy - do not panic!
According to statistics, about 5% of pregnant women who take the test receive unfavorable results, but 90% of these women subsequently have healthy children. It should be taken into account that the analysis of AFP during pregnancy can not in itself cause a diagnosis, it is just a marker for determining the risk. In addition, the analysis of AFP itself in pregnancy does not have a full informative value: it must be carried out together with ultrasound, and also with analysis of the levels of hCG and free estriol (the so-called triple test).
The need to submit the analysis and the timing of its conduct should be set by the doctor. To carry out the analysis, blood from the vein is taken - in the morning and on an empty stomach (if there was a breakfast, it should take at least 4 hours to donate blood). If the result is unfavorable, the doctor will advise to undergo the analysis again and send the pregnant woman to a more complicated ultrasound and prescribe an analysis of the amniotic fluid. It is also likely to need a geneticist consultation.