Pregnancy is a beautiful time, full of expectation and enthusiasm for a new family member.
The first weeks of pregnancy are exciting but can be anxious, even for first-time mothers. Like most expectant mothers, you can be reassured that your baby is normal and healthy. We as doctors are just as interested in your family and in making sure you have a smooth pregnancy and a healthy baby.
Most pregnancies end happily with the birth of a healthy baby. At the same time, however, each woman has a small inherent risk of having a child with a chromosome abnormality. Prenatal screening is designed to identify women who are at risk of giving birth with such abnormalities. Scientific research over the last 2 decades has shown that an ultrasound scan between 11-14 weeks can help detect up to 85-90% of such chromosomal abnormalities.
What is first-trimester screening?
Early trimester screening, commonly referred to as first-trimester screening, usually involves both a maternal blood screening test and an ultrasound test.
Why is the first trimester screened?
The purpose is to check whether the baby has chromosomal problems (such as Down syndrome or Edward syndrome) or birth defects (such as heart problems). It is important to understand that this is a preliminary test, not a definitive diagnosis. If the results raise concern, another test is needed to confirm or rule out the diagnosis.
What are chromosomal abnormalities?
Our bodies’ cells include microscopic components known as chromosomes. These chromosomes carry genes that determine how we develop. In most humans, each cell has 23 pairs of chromosomes. When our body makes the cells it needs to make a baby, the chromosome pairs divide and rearrange themselves. Sometimes these pairs of chromosomes don’t split correctly by mistake, and the baby’s cells may have an extra copy of chromosome 21. Trisomy 21—also known as Down’s syndrome—is brought on by this.
The extra chromosome cannot be removed from the cell, so there is no cure for the condition.
What does trisomy 21 screening negative mean?
A trisomy 21 screening negative means that no indication of Down syndrome, caused by an extra copy of chromosome 21, was detected in the screening test.
What is Down’s Syndrome?
Down’s syndrome is the most common chromosomal abnormality, where babies are born with an extra chromosome 21. Down’s syndrome occurs in 1:700 pregnancies worldwide. The term “syndrome” refers to a set of distinguishing characteristics. Some people with Down’s syndrome are more severely impacted than others when it comes to learning challenges.
Will the tests tell me for sure if my baby has Down syndrome?
We begin by offering all women a test that does not carry the risk of miscarriage. A screening test is the name for this kind of examination. Screening tests don’t give a definitive answer, but they can help us tell which children are at higher risk of developing Down’s syndrome. This is why we only offer a diagnostic test for women who are at increased risk.
Combined first-trimester screening test:
At this clinic, you can choose to have a screening test for Down’s syndrome which includes a scan and blood test. You can take this test between weeks 11 and 14 of pregnancy.
At this stage of pregnancy, all babies have a very thin film of fluid under the skin on the back of the neck. We can measure this as part of the scan and this is known as nuchal translucency measurement.
The blood test measures the amount of certain substances passing from the baby to the mother. If a baby has Down’s syndrome, different amounts of this substance can be found in the mother’s blood. Blood test results are combined with nuchal translucency measurements, along with the mother’s age, weight, and stage of pregnancy, to determine the likelihood that your baby will have Down’s syndrome. It is a combined test and the result is given as a risk diagram.
Second Trimester Screening:
This is a blood test and can be done between 14-20 weeks of pregnancy. The results are given as a risk diagram. Why is first-trimester screening important?
First-trimester screening is important for several reasons:
Diagnosis at an early stage: These screenings can detect possible chromosomal abnormalities and other fetal health conditions in the early stages of pregnancy, enabling timely and appropriate medical intervention and counseling.
Enhanced Bonding: The process of going through screenings and learning about the developing baby can create a deeper bond between expectant parents and their growing baby.
Conclusion
Embrace this exciting chapter in your life with confidence.