Pregnancy is a period lasting for average 9 months 10 days or 40 weeks. Pregnancy is considered in 3 terms. The first 3 month is “Trimester 1” month 4-6 is “Trimester 2”, month 7-9 is “Trimester 3.” The first 3 month period of the pregnancy in other words “Trimester 1” is a more difficult term than other terms due to sharp changes because of progestogen secreted and adaptation period of the body to the pregnancy.
Patient assessment and preparation for the pregnancy prior to pregnancy is the pregnancy care. The processes are as follows:
• Confirmation of the pregnancy (Ultrasonographical or blood pregnancy test - ẞ-hCG)
• Routine pregnancy tests (blood and urinary tests)
• Genetic screening tests (Down syndrome-Trisomy 21, Trisomy 13 and Trisomy 18)
Pregnancy ultrasound examinations are performed by the obstetrician and gynecologists without directing the patient to radiology department or other centers for ultrasonography.
What’s genetic screening test?
It is investigated whether the infant is in risk group in terms of chromosome anomalies, Down syndrome- Trisomy 21, Trisomy 13 and Trisomy 18 or not. According to the test results, the expectant parents are informed whether the infant is in the risk group for the said chromosomal anomalies or not. Considering these test results, it is not possible to say that “Your baby is exactly healthy or ill”.
1. Trimester screening test 11-14 test
It is performed in week 11-14 of the pregnancy. Thickness of nape (nuchal transluceny) measurement and PAPP-A in the mother’s womb and free ẞ-hCG hormone is examined and risk is calculated for Down syndrome-Trisomy 21, Trisomy 13 and Trisomy 18. During this screening test, parameters contributing to evaluate health of the baby are examined at our clinic.
These parameters are:
• Nasal bone of the baby
• Facial angle
• Intracranial translucency: Ductus venosus doppler examination for early diagnosis of Spina bifida
• Hepatic artery Doppler examination
• Uterine artery Doppler examination: determination of preeclampsia-pregnancy hypertension and restriction of development in pregnancy.
• Measurement of cervix length: determination of risk of preterm delivery
2. Trimester screening test (Triple-Quadruple test)
It is preferred for the patients not having 1. Trimester screening tests. It is performed in weeks 15-21 of the pregnancy. In addition to fetal biometry, free ẞ-hCG, estriol, AFP (triple test) and inhibin (quadruple test) is examined and risk is calculated for Down syndrome-Trisomy 21, Trisomy 13 and 18.
Important note: Only one genetic screening test is recommended for every pregnant at our clinic and it is 1. Trimester test ( 11-14 test). We recommend 2. Trimester screening test (triple-quadruple test) for the patients not having 1.trimester screening test. If both tests are conducted and evaluated separately, amniocentesis will be applied to 10 of 100 pregnant (due to false positivism) unnecessarily. Integrated screening test method is applied to perform two tests together and programs yielding one result are should be used and the result should be evaluated.
Screening test results are evaluated by your doctor and your risk condition is determined. “Genetic diagnosis tests” are recommended for the patient in high-risk group.
Genetic Diagnosis Tests
Genetic diagnosis test is performed for the pregnant in high risk group by the results of screening tests and chromosomes of the baby are determined and whether there is numerical and structural anomaly of chromosomes or not is determined and final result is obtained.
These tests are as follows:
Chorion Villus sampling (CVS): Fetal cells are aspired from the placenta by accessing needle in the mother’s womb between the weeks of 11-14 of the pregnancy and genetic examination is performed.
Amniocentesis: Sample is taken from amniotic fluid (the fluid where the baby develops) by accessing with a needle in mother’s womb between the weeks of 16-22 of the pregnancy.
Cordocentesis: Blood of the baby is taken from the umbilical cord of the baby by means of a needle in mother’s womb after week 20 of the pregnancy.
Performance of pregnancy care with ultrasonography (2 –dimension, 3 and 4-dimension, color Doppler and power Doppler)
18-23 week genetic sonogram (detailed ultrasonographic examination): organ development of the baby is examined.