Screening for the 2nd trimester

Of course, every future mother wants to believe that her baby will be born healthy. But, as practice shows, various pathologies of the fetus are not so rare.

Such diseases as Down's syndrome, Edwards, and many other chromosomal abnormalities are cunning enough:

• First, it is impossible to predict their development in advance (as a rule, pathology is formed immediately after conception, and neither parents nor doctors can influence this process);
• secondly, these diseases are difficult to reconcile with a full-fledged life, they do not succumb to either medication or surgical treatment, and the born babies can be said to be doomed to suffering;
• thirdly, it is very difficult to diagnose the disease in utero. Even the most recent research methods are not always able to make a final verdict. In most cases, only the percentage of probability of a child with anomalies is announced to the parents. And the decision to keep pregnancy or not, remains for them.

Nowadays, doctors recommend that all pregnant women undergo perinatal screening in the first and second trimester of pregnancy in order to identify the risk of having a baby with severe developmental ailments. This examination is considered the most reliable.

What is meant by perinatal screening of the 2nd trimester?

During the entire period of pregnancy, prudent future mothers undergo two prenatal screening: in the 1st and 2nd trimester. However, the second screening is more informative, because at such a time it is much easier to understand what deviations from the norm in the analyzes may mean, and some pathologies are already clearly visible on the ultrasound.

In general, perinatal screening of the 2nd trimester means:

1. Biochemical screening of the 2nd trimester (triple test), which shows nothing but compliance with the norms of the values ​​of the three elements in the mother's blood (AFP, hCG, estriol).
2. Screening ultrasound is an extensive study (the structure of the fetal internal organs is carefully examined, the condition of the placenta and amniotic fluid is determined).
3. Cordocentesis is an additional study conducted according to the indications of doctors.

Indicators and norms of the second screening for pregnancy

So, in the process of screening, the AFP level is determined. AFP is a protein that is produced by the fetus. Normally AFP can fluctuate within 15-95 U / ml, depending on how many weeks the second screening was done. If the results obtained were higher than normal, doctors may suggest a violation of the development of the spinal cord or a defect of the neural tube. Underestimated AFP may indicate a number of diseases, such as Down's syndrome , Edwards syndrome, or Meckel syndrome. However, in such situations, the interpretation of screening is very ambiguous.

The second thing that doctors see after the second screening is the level of estriol. Its value should increase with the increase in the gestational age. Underestimated estriol may indicate chromosomal abnormalities (Down syndrome) or the threat of premature birth.

Also, chromosomal pathology is indicated by an elevated level of hCG .

As for screening ultrasound, then you should rely only on the professionalism and care of the doctor who conducts the procedure.

When do the second screening?

Depending on how many weeks the second screening was done, correction is introduced when deciphering the results. Basically, experts recommend not to delay with the survey and have time to submit the necessary tests before the 20th week. The optimal time for the second screening for pregnancy is 16-18 weeks.