2 trimester screening
Pregnancy And Childbirth / / August 12, 2017
How is the screening of the second trimester
second trimester of pregnancy for many women marked by screening, triple test for fetal chromosomal pathology.This study is considered to be slightly less informative than the one that is carried out at the end of the first trimester.Nevertheless, biochemical screening and 2 trimester ultrasound can and are seen as objective data for the calculation of risks and even make an accurate diagnosis.
What is a study of the above, what is its informative value, may it be a mistake?Screening of 2 terms - is a complex medical interventions, blood from a vein and ultrasound, the results of which are entered into a computer program to calculate the risk of Down syndrome, Edwards, Patau, Turner, triplodii and others.
This decoding results of biochemical screening program 2 terms given in the form of quantitative risk.For example, "Down syndrome - 1: 1800.This means that a woman of the same age in 1800, with the same features of the pregnancy, the results of ultrasound and a blood test, a child is born with this pathology.
Since just numbers risk many women are not taken seriously, they decide to go only part of the survey.Namely, ultrasound screening for 2 terms, which can demonstrate malformations of organs and systems of the fetus, to assume his genetic disease on the basis of some markers, such as the shortening of the nasal septum or the absence of the phalanx of the little finger.In addition, prenatal screening for second trimester makes it possible to diagnose overt congenital malformations face, heart, stomach, brain and spinal cord, urinary tract and kidney integrity.Many of these abnormalities are indications for abortion, since it is not subject to surgical treatment and do nonviable fetus.Also, some markers that indicate genetic abnormalities, but can not always be identified.For example, pyelectasia kidneys, hyperechoic inclusions into the heart, hyperechoic bowel, and so on.. These markers require re-examination.And trimester blood screening 2 is very useful in this case.But even if the screening results will be good, after 2-3 weeks of repeated ultrasound.It is desirable to make the ultrasound expert class, consider the problem areas, including in 3D mode, so the information will be more accurate.
1 trimester screening and a second screening during pregnancy are different methods of implementation.So, at the first screening it is very important to accurately observe the deadlines for a blood test and an ultrasound.This should be done necessarily in one day.And the timing of the second screening in pregnancy for ultrasound and biochemical analysis differ.So, the future mother donates blood alpha-fetoprotein (AFP), free in-hCG and ekstriol on term of 16-18 weeks.Adherence to this deadline is necessary!But the US is the most informative on term of 20 weeks.However, only effective biochemical screening no more than 70%.That is about 30% of the favorable results of blood tests are false-negative, those who gave them will have children with Down syndrome or Edwards.
At the same time, the adverse effects of screening 2 terms are usually an indication for invasive diagnostics.On a longer term is either amniocentesis (16-20 weeks), or cordocentesis (over 20 weeks).Moreover, amniocentesis is less dangerous in terms of complications in the form of late spontaneous miscarriage or premature birth.Sometimes it happens that 2 trimester screening standards for ultrasound shows a baby is born with the syndrome ... The reason for this is the lack of some markers of chromosomal abnormalities, poor visualization by ultrasound, and sometimes even carelessness doctor.
Many women are poorly versed in how to make a screening ultrasound 2 trimester blood tests are dealt.And try to pass these examinations independently.Err on the timing of the obtained results of blood tests without calculated risks - all this makes screening very misleading.After deciphering the results of the second trimester screening - it is the task of a special computer program, not a pregnant woman or her doctor.By the way, to perform biochemical analysis of blood in this case is not necessarily all in a row expectant mothers.The coupons are usually issued only to those who had a bad first screening, a second screening during pregnancy carries a clarifying nature.
sure to pass this examination as women older than 35-40 years, and no matter whether they have their own children, suffering from alcoholism and (or) drug addiction, surviving severe viral disease in the early stages of gestation, those who already havechildren born with a chromosomal abnormality, if closely related status, and reception of drugs having toxic effects on the fetus.
to influence the accuracy of the results are such facts as IVF, multiple pregnancy, maternal diabetes, too little, or a lot of weight a woman, some bad habits.