Screening Tests

Studies required during pregnancy:

After pregnancy is detected, your doctor will ask you for some tests within the first 12 weeks. The purpose of this is to diagnose a problem early and intervene in time, if any, before the pregnancy progresses.

These tests:

• Blood type
• Hemogram (blood count)
• Complete urinalysis
• Urine culture
• TSH
• HbsAg
• Anti HCV
• AntiHIV
• Rubella IgM
• Sphilis
• CMV IgM
• Toxoplasma IgM.

After evaluating you, your doctor will request some of these tests, perhaps more.

Screening Test in Pregnancy

Dual The test

• It is performed between the 11th and 14th weeks.
• This test, which is performed by taking blood from your arm, has no harm to the mother and the baby.
• It is not mandatory.
• The dual test is a screening test for two genetic diseases called trisomy 21 (Down syndrome) and trisomy 18.
• Like all screening tests, the dual test does not give definitive results, only these two genetic diseases. It shows the possibility of the disease in your baby. In other words, a good result of the double test does not mean that there is nothing in the baby, or vice versa, if the result is risky, it does not indicate that the baby has Down syndrome.
• The position of your baby is very important for this test to be performed, because the test is evaluated. Your baby's nuchal thickness should be measured accurately, if possible, the nasal bone should be seen clearly.
• A nuchal thickness of more than 3 mm increases the risk of Down syndrome.

What is Down Syndrome? ?

• Down syndrome, trisomy 21; It is a genetic difference that results from the presence of an extra chromosome in the 21st chromosome pair as a result of a genetic irregularity.
• Down syndrome is often associated with disorders in mental cognition and differences in physical development, such as typical facial appearance.
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• It often has problems such as mild or moderate learning disabilities.
• Down syndrome is a disorder that can be identified during pregnancy or at birth.
• Down syndrome has a rate of 1 in every 800 to 1000 births. It is found in; Statistics have shown that this rate increases with increasing maternal age.
• Typical facial features of Down syndrome, in addition; A single deep palm line instead of a double one on the palm of the hand, an almond-shaped eye caused by epicanthic folding, a palebral cleft, low muscle tone, a larger gap between the big toe and the second toe, and a drooping tongue morphology can be seen. There is no rule that all of these symptoms will be seen, some may be present and some may not be.
• The main health problems caused by Down syndrome are the risks of congenital heart failure, gastroesophageal reflux disease, recurrent ear infections and thyroid disorders.
• Thanks to family and medical support and early intervention in the early stages of childhood, people with Down syndrome can establish a socially integrated life with support.
• Children with Down syndrome are generally larger in terms of height and weight. They grow up slowly, learn more slowly, and have more difficulty solving problems and making decisions than other children. Intelligence levels remain lower than normal.

What is Trisomy 18?

• Trisomy 18 also known as Edwards syndrome (Trisomy E) 6000 It is a chromosomal abnormality that occurs once in a live birth.
• While normally there are two pairs of each chromosome in all human cells, this anomaly has three pairs of chromosome 18.
• Approximately 80% of babies with this syndrome have this syndrome. It is a female baby.
• The incidence of trisomy 18 increases as the mother gets older.
• Approximately 90% of pregnancies with trisomy 18 chromosomal structure are lost in the womb during the embryonal period or the fetal period.
• 90% of those born alive die before they turn one year old.

Approximately half of babies born with Edwards syndrome die in the first week.

Abnormalities seen in Trisomy 18:

• Mental retardation.
• Heart anomalies are the most common (VSD, ASD).
• Kidney anomalies (horseshoe kidney).
• Omphalocele, gastroschisis.
• Growth retardation in the womb.
• Growth failure.
• Polyhydramnios.
• Hand and foot anomalies observed in trisomy 18 are typical. (C lenched hand, club foot or rocker-bottom feet, radius aplasia).
• Eating and breathing difficulties after birth.
• Double test, triple test, quadruple test or ultrasonography performed during pregnancy Examinations can provide information about the presence of trisomy 18, but a definitive diagnosis cannot be made with these methods.
• For a definitive diagnosis, chromosomal examination with CVS or amniocentesis is required. In cases where the diagnosis was not made before birth, the diagnosis is made by chromosomal analysis after birth. In chromosome examination, it is seen that the 18th chromosome has three pairs.

Triple Test, Quadruple Test

• In fact, the quadruple test is one of the triple test. It is an advanced version, especially if you are under 35 and have the opportunity, I recommend you to have a quadruple test because the reliability of the quadruple test is much higher than the triple test, especially in people under 35.
• This test, which is done by taking blood from your arm, has no harm to the mother and the baby.
• It is not mandatory.
• These tests are performed between the 16th and 20th weeks. The disadvantage of these tests, which are performed approximately 1 month after the double test, is that information about Down syndrome and trisomy 18 is approximately 1 month late.
• The advantage of these tests over the double test is that they give us an idea about cerebrospinal development disorders called neural tube defects. .
• Since these tests are screening tests, they do not give definitive results.
• If your result is indicated as risky in the double, triple, quadruple test and whether your baby has Down syndrome or trisomy 18 diseases. If you want to know for sure, you should definitely benefit from diagnostic procedures such as chorionic villus sampling, amniocentesis, cordocentesis.

What is Neural Tube Defect?

• The structure called the neural tube is a structure that starts from the brain tissue and extends downwards, including the spinal cord. Disruption of development for any reason causes any part of the tube to remain open. This condition is called neural tube defect.
• If the opening is somewhere along the spinal canal, it is spina bifida, and if it is in the skull, it is encephalocele or anencephaly.
• Spina bifida is a condition between the two vertebrae. It is a defect in which the halves cannot meet at the midline. The membranes surrounding the spinal cord alone (meningomyelocele) or the spinal cord tissue together with the membranes (meningomyelocele) herniate from the area that remains open in the midline.
• Spina bifida is most commonly seen in the lumbar region.
• Spina bifida in our country is approximately It is a congenital defect observed at a rate of 3 in 1000.
• It is more common in those with insulin-dependent diabetes and those with epilepsy.
• Recurrence of the event is observed in expectant mothers who use high doses of folic acid after birth with spina bifida. The decrease in the probability supports the view that the defect may have a close relationship with folic acid.
• In the detailed ultrasonography examination performed during pregnancy, some signs in the head (narrowing of the region called the posterior fossa, deformity in the skull) raise the suspicion of spina bifida, while the above-mentioned signs The absence of spina bifida is reassuring.
• In large defects, as the pregnancy progresses, fluid accumulation in the head (hydrocephalus) also occurs.
• In addition, the value obtained in the triple and quadruple test or in the alphafetoprotein examination requested alone If it is higher than expected according to the week of pregnancy, it also brings up the possibility of spina bifida.
• The definitive diagnosis is made by seeing the defect in ultrasonography.

Level Ultrasound (Detailed Ultrasound)

• In normal pregnancy follow-up, fetal anomaly screening is performed by gynecologists between 17-22 weeks.
• Fetal anomaly screening (first level ultrasonography) is performed in every normal, risk-free pregnancy. It is performed to investigate the presence of a congenital defect (anomaly).
• When a risk or suspicion is detected in the fetal anomaly scan, the patient is referred to a detailed (second level) ultrasonography examination for detailed examination.
• Here, the perinatologist examines again. and gives detailed information to the family about the baby's condition.
• The examination takes approximately 20-30 minutes.
• Sometimes, if there is a suspicion, ultrasonography is performed again after 3-4 weeks, but if no suspicion or risk is detected, normally It is done once during pregnancy and cannot be done again.
• Detailed ultrasonography reveals the inside of the baby's head, brain, spine (waist). openness), inside the chest, heart, abdominal organs, stomach, intestines, kidneys, arms, legs (introversion in the hands and feet), fingers (deficiency or excess), face (cleft palate, lip), etc. Every organ is examined in detail.
• In addition, the baby's water and placenta (the baby's partner) are evaluated.
• Even if detailed ultrasonography is performed by the most experienced specialists in the best centers, it can never detect 100% of the anomalies in the baby.
• About 70% of anomalies can be detected on average.
• Because some anomalies do not show symptoms that can be detected on ultrasound, some anomalies develop in later months after ultrasound.
• Normally, approximately 10% of all pregnancies occur. Approximately 2-3 of them have anomalies (congenital defects).
• In identical twins and consanguineous marriages, this rate increases to 4-5%.
• Another issue that should not be confused is the 4-dimensional ultrasound examination of the baby's face. Seeing hands and feet is not enough for a detailed ultrasound, it can never replace it.
• Although 4-dimensional ultrasound is very enjoyable for the expectant mother, it does not provide an advantage in detecting anomalies in the organs.
• In detailed evaluation, normal 2-dimensional ultrasound is used to detect developmental disorders in the fetus. Ultrasound examination is used.

Sugar Loading Test

• Although the expectant mother did not have diabetes before pregnancy, glucose, that is, sugar, in the blood during pregnancy. There may be an increase in the level.
• This is a development that will indicate gestational diabetes in the expectant mother.
• Sugar load test should be applied to expectant mothers between 24 and 28 weeks.
• During the test. The expectant mother is first given 50 g of glucose.
• An hour later, the glucose level in the blood is checked.
• During the determination of this rate, when the glucose level is below 140 mg/dl, it is determined that the expectant mother does not have gestational diabetes.
• However, if the glucose in the blood exceeds this value, the test must be repeated with 100 g of glucose for 3 hours.
• After the loading, which will last for 3 hours, it is definitely determined whether the expectant mother has gestational diabetes.
• We can now perform a one-time 75 gram sugar test instead of 50 and 100 gram sugar tests.

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