Prenatal Screening: Specific Blood Test, Procedures, Outcomes, and Potential Hazards
Pregnancy brings about significant changes in a woman's life, both physically and mentally. Among the visible changes is the transformation of the mother's body, yet the most critical change occurs invisibly as the baby grows inside her. Regular medical check-ups, including the quadruple marker test, are essential to ensure the baby's healthy development.
Also known as quad screen or quadruple marker test, this blood test assesses the risk of certain health issues in the baby, such as Down syndrome, trisomy 18, and neural tube defects like spina bifida. The test is conducted during the second trimester of pregnancy, between 15 and 20 weeks, and can provide valuable insights into the baby's health and potential genetic conditions.
The purpose of the quadruple screening is to identify chromosomal abnormalities. Based on the results, doctors may recommend invasive diagnostic tests, like amniocentesis, to gain a better understanding of the baby's condition. Although the quadruple test only highlights the likelihood of the baby having a birth defect, it does not pose any health risk to the mother and baby.
To undergo the quadruple marker test, women should consult their healthcare physician for guidance. The test's recommendation depends on the mother and baby's risk factors, such as age, family history of birth defects, and previous children born with birth defects. High-risk women, such as those over 35, women with a family history of birth defects, and women with type 1 diabetes, should consider the test more seriously.
The screening involves analyzing a blood sample to measure levels of four substances: alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), unconjugated estriol, and inhibin A. AFP can indicate the possibility of the baby having spina bifida and anencephaly, a severe neural tube defect causing the absence of parts of the brain and skull. hCG is a hormone produced by the placenta during early pregnancy, and low estriol levels may indicate the possibility of Down's syndrome or Edward's syndrome (Trisomy 18). Inhibin A indicates the possibility of the baby having Down's syndrome.
The quadruple marker test results are then computed using a formula that takes into account the baby's gestational age, the mother's age, and other factors. The results are expressed as a risk assessment ratio for Down's syndrome, trisomy 18, and neural tube defects. Higher risk ratios indicate a greater chance of the child having one of these conditions.
Normal test results indicate that the baby is healthy, whereas abnormal results do not necessarily mean that the baby has a birth defect. False positives may occur due to inaccurate gestational age or other factors, and further tests, such as an ultrasound, amniocentesis, or chorionic villus sampling, may be needed to eliminate the risk of a positive quad screen test for Down's syndrome.
The quadruple marker test has a detection rate of approximately 75-80% for Down syndrome and over 85% for neural tube defects. The test's false positive rate is 5%. Factors such as multiple pregnancies, the effect of in vitro fertilization, diabetes, and chemical interference can influence the test's accuracy.
In conclusion, the quadruple marker test plays a crucial role in assessing the risk of certain genetic disorders and birth defects in the baby. Normal test results provide peace of mind, while abnormal results require further investigation. It is essential to consult with a qualified medical professional for guidance and interpretation of the test results.
Sources:
- Nemours Kids Health - Prenatal Test: Multiple Marker Test
- Cleveland Clinic - Quad Screen
- American Pregnancy Association - Quad Screen Test
- Mount Sinai - Quadruple screen test
- Genetics in Medicine - Second trimester maternal serum screening for fetal open neural tube defects and aneuploidy
- Pregnancy involves regular medical check-ups, such as the quadruple marker test, to ensure the baby's health and screen for potential medical-conditions like Down syndrome, trisomy 18, and neural tube defects.
- This test, also known as quad screen or quadruple marker test, and conducted during the second trimester of pregnancy, measures levels of four substances to identify chromosomal abnormalities, including AFP, hCG, unconjugated estriol, and inhibin A.
- CBD, a popular wellness supplement, should not be used during pregnancy without consulting a healthcare professional, as its effects on pregnancy, fetal development, and certain medical-conditions, including cancer, are still under scientific study.
