- And we have the youngest - Down - sadly my mother said.
- How?! A screening you do?
- No, we somehow did not send. We decided that two children of normal, nothing to spend money. And then in the hospital taken aback ...
I have no words. After all, a woman in childbirth to leave is not getting any younger, and the risk of having a child with Down syndrome It increases significantly after 35 years! Immediately I remembered another conversation. Two years ago at the antenatal clinic patient he told me, "We girls talked in the hallway and decided: screening - This is for those who have money to spare. "
Apparently, those who have no extra money, it can grow and maintain a disabled child. But people Down syndrome They live very long, and it can survive their parents. Who they are needed? The State? Do not make me laugh.
Women often do not fully understand how and why we study, doctors suggest holding. Let's define what prenatal screening .
The English word «Screening», means "to sift." In medicine skringovye study conducted for the fact that to a large group of people quickly find a small group in which the risk of developing certain diseases is high. Today we talk about screening to identify groups at risk of birth defects in the fetus.
Currently, it recommended holding prenatal screening the following types of congenital malformations in the fetus:
- Down syndrome (trisomy of the twenty-first pair of chromosomes).
- Edwards Syndrome (trisomy of the eighteenth pair).
- Neural tube defects (spina bifida and anencephaly).
The key to understanding this problem is the word "risk". These terrible state meet not so rare. For example, the probability of having a child with Down syndrome It is 1 in 700 births. Edwards Syndrome rarer - 1 time for 7000 delivery. The frequency of spina bifida ranges from 1 to 2 per 1000 live births.
Theoretically, every pregnant woman has some risk of having a child with severe genetic diseases. It is clear that an individual's risk increases if mom older than 35 years or were born in the family have kids with such defects. It is clear that even if the risk is 1: 2 chance of having a healthy baby is as much as 50%.
Screening - this is not a diagnosis. Screening - A way to select a group of pregnant women in whom the risk of having a baby with a birth defect is so large that it is necessary to conduct studies qualifying.
Let us clearly define: what we do and why?
Why do the screening?
1. We conduct the most accurate screening combined with computer processing of information in order to calculate the risk for each patient.
2. If the risk is high, it is necessary to conduct a study to clarify - depending on the duration of pregnancy, chorionic villus biopsy or amniocentesis. The goal - we obtain fetal cells, a geneticist and a good doctor will determine its chromosome set. We not only see exactly where a boy or a girl. We will definitely know if everything is OK with the chromosomes, suspicions and risks finally disappear or turn into a diagnosis.
3. If genetic research confirms that the fetus has a severe genetic pathology, couples will be asked to terminate the pregnancy.
Prenatal screening In principle, is voluntary. So make a decision on whether or not to take this analysis, it is necessary to the very end. Let's examine the information well and honestly answer the question: if I'm ready to give birth to such a child. It is unpleasant and difficult topic, but it must begin. I really do not like the style of reasoning "as God wills." There is some movement concepts. "The Lord sends us to the test." Test - this is not necessarily the birth and upbringing a sick child. Maybe the test - it's just all the action to be taken, that this child is not born. Any treatment such anomaly exists.
If you are not willing to terminate a pregnancy, do not do the screening. It really is "thrown out money."
All done, screening carried out, and the risk of getting high - it is an occasion to continue the movement, not for tears and tantrums. Remember, the risk - it is not a diagnosis. We go to invasive diagnostics.
Of course, you are obliged to warn, and warn that the use of invasive methods there is a risk of abortion. For this reason, doctors all over the world, and bother with the biochemical markers and complex computer calculations - we can not safely hold the fence material for genetic testing to all pregnant women. Genetic testing of the material obtained from the fruit will exclude or confirm a chromosomal abnormality.
If you are not willing to give consent to invasive diagnostics, do not do the screening. It really is "thrown out money."
Women who do not fall into the risk group do not need to conduct more invasive research. But the good result of screening - is not a guarantee! The risk is still there. He's just a little, and it is a material point in physics, can be neglected. It is not appropriate to carry out expensive and risky research all in a row - use a little, a lot of problems. With the same success it is possible to "child" in the selection of IVF embryos. It is very difficult, very expensive, but effective.
How do the screening?
The more accurate and correct information will be collected, the lower the probability of errors in the calculation of risk. The sooner we know about a problem, the better we can handle it. Screenings I and II trimester of pregnancy are different - use different biochemical markers.
The algorithm of prenatal screening I and II trimester:
1. We expect pregnancy.
I trimester screening within the period of 10 - 13 weeks of pregnancy. An error in the calculation of pregnancy significantly reduces the accuracy of the calculation of risk. I remind you that the term of pregnancy in obstetrics is considered to be from the first day of the last menstrual period. If the cycle is irregular, an obstetrician-gynecologist would think, to assess the size of the uterus, to do ultrasound, etc. In any case, on the referral form, we are brought to the attention of the average length of the menstrual cycle, the length of the shortest and longest cycle at irregular periods.
2. Make ultrasound.
US carries a specially trained person in terms of 10-13 weeks of pregnancy. This is a very important study. These measurements will be needed for the calculation of risks and I and in II-trimester. The doctor must measure the CTE - coccyx-rump length and TVP - nuchal translucency. The correct definition of RTA requires a good ultrasound device with high resolution and special skills of the doctor.
Optimally conduct ultrasound after 11 weeks, during this period fails to notice the majority of gross malformations:
- Diagnosis of omphalocele is possible only after 12 weeks.
- Diagnosis of anencephaly is possible only after 11 weeks of pregnancy, because only this period appear ultrasound signs of ossification of the fetal skull.
- Evaluation of four-chambered heart and large vessels is possible only after 10 weeks of pregnancy.
- Bladder is visualized in 50% of healthy fetuses at 10 weeks, 80% - 11 weeks and all fruits - 12 weeks.
Recently, in addition to measuring the RTA for the diagnosis of Down syndrome at the end of the first trimester ultrasound, the following signs:
- Determination of the nasal bone. At the end of the first trimester nasal bone is not determined by ultrasound at 60-70% of fetuses with Down syndrome and only 2% of healthy fruit.
- Assessment of blood flow in arantsievom (venous) duct. Violations of the waveform of blood flow in the duct arantsievom detected in 80% of fetuses with Down syndrome, and only 5% of chromosomally normal fetuses
- Reducing the size of the maxilla
- Increase in the size of the bladder ("megatsistit")
- Moderate tachycardia in the fetus.
If a patient came to the ultrasound screening for early study should be repeated in the correct period.
No, do not do too much harm US! Harmful not receive the necessary and important information.
3. properly execute directions.
On how fully and correctly executed the direction depends on the accuracy of calculations.
The weight and gestational age on the date of blood, race, diabetes, a history of smoking, pregnancy resulting from IVF, a complete list of drugs that are taken during pregnancy with dosage, the birth of children with genetic disorders in the past, these US - all of these factors included in the calculation of risk.
4. We pass the blood.
Donate blood for biochemical screening should be as close as possible to the US. Ideal: US yesterday, today blood. Blood collection shall be held not earlier than 3-4 hours after the last meal, ideally - in the morning on an empty stomach.
The set of indicators will be different at different stages of pregnancy. At 10-13 weeks of pregnancy tested the following indicators:
- Free β-subunit of human chorionic hormone human (St. Β-hCG)
- PAPP-A (pregnancy associated plasma protein A), associated with pregnancy plasma protein A
In the I trimester calculated risk of detection in the fetus Down's syndrome and Edwards syndrome . The risk of neural tube defects by double test can not count as a key indicator for determining the risk is α-fetoprotein, which is only beginning to define the second trimester of pregnancy. If the results of the test in the first trimester indicate a risk of chromosomal abnormalities of the fetus, to exclude the diagnosis of chromosomal abnormalities to the patient can be carried out chorionic villus sampling.
The gestation of 14 - 20 weeks of the last menstrual period (Recommended dates: 16-18 weeks) are determined by the following biochemical parameters:
- Total hCG or free β-subunit of hCG
- Α-fetoprotein (AFP)
- Free (unconjugated) estriol
According to these indicators are calculated the following risks:
Down syndrome (trisomy 21)
Edwards syndrome (trisomy 18)
neural tube defects (cleft spinal canal (spina bifida) and anencephaly).
Explanation of the screening results
A sea of tears shed over our women obscure and terrible words on the blank answers.
We look at the schedule, looking for a black bar that grows from the numbers corresponding to your age. The bar in the green zone - great in the yellow zone - go, a column in the red zone - welcome to amniocentesis or chorionic villus sampling - the risk is high.
To write using information from the article II Guzova "Prenatal screening in IDC group of companies"
- All posts gynecologist
Blog gynecologist
Go back to the main page
Немає коментарів:
Дописати коментар