Procedure for conducting a double pregnancy test
Prenatal examination includes ultrasonic and biochemical (blood test) screenings. Do not worry: these tests are absolutely safe and do not affect the health of the expectant mother, the course of pregnancy and the development of the baby. Doctors recommend such tests to all pregnant women. The results of the studies do not give an accurate diagnosis, but only help to detect a group of risk of chromosomal abnormalities. For example, as a result of changes in 21 chromosomes, a baby can be born with Down's syndrome (dementia). And if not everything is in order with the 18th chromosome, then the child may develop oligophrenia (Edwards syndrome).
What is the procedure for conducting a "double" pregnancy test?
In the morning on an empty stomach, a future mother gives blood from a vein to determine two parameters:
- ? -HGH (free? subunit of human chorionic hormone);
- PAPP-A (pregnancy associated plasma protein A), plasma protein A, associated with pregnancy.
A change in the level of these proteins indicates a risk of the fetus having chromosomal abnormalities. Biochemical screening is supplemented by ultrasound examination of the collar zone of the fetus (it is also called the "width of the cervical transparency" or "cervical fold"). Ultrasound shows the accumulation of subcutaneous fluid on the back surface of the child's neck. If the doctors found that the baby is unbending the head, then this value can increase by 0, 6 mm. And if you bend, then decrease by 0, 4 mm. The threshold value of this indicator is 3 mm.
Suspicion of pathology is caused by high numbers. In this case, the doctor looks at other signs of chromosomal abnormalities. For example, if the crumb does not determine the nasal bone or the blood flow in the acacia sinus is violated, then this may indicate Down's syndrome. Also about genetic abnormalities say an increase in the size of the bladder, tachycardia, a decrease in the maxilla in the child.
However, the increased risk is not yet evidence that the baby is not all right. Such indicators are only an occasion for more careful observation.
Results of a double pregnancy test
In order to find peace and confidence that the baby grows and develops normally, doctors recommend the "double" test to all women. The results of this analysis are often presented in units of MoM (multiples of median). This is a coefficient that indicates the degree of deviation of the indicators of a particular analysis from the mean. If everything is normal, then MoM on the entire pregnancy should be from 0, 5 to 2. Ideal option - unit. But in the case of different genetic pathologies of fetal development, all values ??of MoM in the screening performed are simultaneously different.
If the results of the "double" test showed a decrease in the concentration of the free? -subunit of human chorionic hormone, then this may indicate a threat of miscarriage. A very low level? -HCG suggests Edwards syndrome. If this hormone in the blood is much greater than it should be in the norm, then doctors will suspect that the baby has Down syndrome. Here there is one "but": an increased rate of? -HCG is absolutely normal in multiple pregnancies. However, the level of ?-hCG increases not only in the presence of a genetic disease in the child, but also in diabetes mellitus.
Do not worry, if you have a high level of plasma protein A (RAPP-A): in the blood of a future mother, this rate increases throughout the gestation period. A very low concentration of RAPP-A should guard you. In this case, this indicates a possible development in the baby syndromes of Down or Edwards.
The deviation from the normal levels of? -HCG and RAPP-A is also promoted by smoking, a significant deviation from the norm of the body weight of the future mother, race, inaccurate information about the date of the onset of pregnancy and other factors. Therefore, do not make hasty conclusions until you are sure that the results of the tests do indeed show the genetic pathologies in the child. To do this, go through ultrasonic and biochemical screenings again, do a so-called chorionic villus villus biopsy. This analysis is carried out through a cut in the abdominal cavity of the mother or through the cervix. Here, an instrument is introduced, which takes a sample of tissues for examination. In the end, you can also wait until 18-21 weeks of pregnancy and make a "third" planned test.
It should be understood that the poor results of a "double" test is not yet a diagnosis, but simply an increased likelihood of a genetic disease in a child. After all, the results of analyzes are affected by many factors. In any case, do not make hasty conclusions on your own. It is best to consult a few doctors and do a second screening. This will help you calm down and make the right decision.
Excellent tests for you and let your baby be born healthy!