Genetic testing in pregnancy provides important information about the health of the foetus, enabling families and medical professionals to make educated decisions about pregnancy. Congenital disorders including spina bifida, Down syndrome, and trisomy 13 can be identified by these tests. It is crucial to remember that Genetic Testing in Pregnancy are voluntary and has to be discussed with a healthcare professional.
Overview of Prenatal Genetic Testing
What is Prenatal Genetic Testing?
Expectant parents might learn about possible genetic conditions or birth abnormalities that a fetus may have from prenatal genetic testing. These tests are optional, in contrast to common prenatal exams like blood type, blood count, or glucose screening. It is crucial to talk with your healthcare practitioner about which tests are suitable for your circumstances. In addition to standard pregnancy tests, some people decide to have prenatal genetic testing.
Chromosome or genetic disorders are caused by abnormalities in an individual. The instructions for how your body works are encoded in genes, which are stored on chromosomes. Congenital diseases can be identified prenatally by genetic testing, and certain problems are present from birth.
There are two main types of prenatal genetic tests: screening tests and diagnostic tests.
Types of Genetic Testing in Pregnancy
Although they do not diagnose genetic disorders, screening tests aid in determining their risk. An aberrant result does not prove the existence of a genetic illness; rather, it suggests a higher risk for one. Medical professionals can assist in interpreting the data and suggest additional actions, such as diagnostic tests if required.
Some common prenatal genetic screening tests include:
Carrier Screening: This blood test looks for genetic alterations that may raise the fetus’s risk of developing single-gene diseases, which are serious medical issues. Spinal muscular atrophy, sickle cell disease, and cystic fibrosis are a few examples.
Testing of the second parent is recommended if one parent is discovered to be a carrier. A severe form of the disease could develop in the fetus if both parents have the same genetic risk. Usually, carrier screening is done just once in a lifetime. To get the most accurate results of Genetic Testing in Pregnancy, contact Risa IVF today!
Checking for Abnormal Chromosome Numbers: One-half of each chromosome should come from each parent when chromosomes are inherited in pairs. Fertilization errors can cause an additional or missing chromosome, which can result in disorders like Turner syndrome (a missing X chromosome) or Down syndrome (an extra chromosome 21).
Types of tests include:
Cell-Free Foetal DNA Screening (NIPT): This non-invasive test examines tiny pieces of foetal DNA in the mother’s blood to search for common chromosomal abnormalities. Usually, this test is carried out ten weeks into the pregnancy.
Serum Screening: To assess the likelihood of chromosomal abnormalities, this blood test measures different protein levels. Sequential screening, quad screening, and first-trimester serum screening are a few examples. Consult your provider as these tests are conducted at particular intervals during pregnancy.
Screening for Physical Abnormalities
Sometimes chromosomal abnormalities result in physical problems in the developing foetus. Blood tests and ultrasounds can be used to determine the likelihood of such problems during pregnancy.
Nuchal Translucency:
At 11 to 14 weeks of gestation, this ultrasound evaluates the thickness of the fetus’s neck and provides information regarding the likelihood of genetic abnormalities and physical malformations, such as abnormalities of the heart.
AFP Screening (Maternal Serum Screen):
This blood test determines the mother’s blood’s AFP level. Elevated levels could suggest anatomical flaws in the fetus’s face, back, or abdomen. The test is performed between weeks 15 and 22 of pregnancy.
Quad Screen:
This test evaluates the likelihood of chromosomal abnormalities and neural tube problems by measuring four chemicals in the mother’s blood. Also referred to as a multiple marker screen, it is carried out between weeks 15 and 22 of pregnancy.
Foetal Anatomy Scan:
This ultrasonography assesses the physical characteristics of the developing fetus, encompassing the heart, lungs, brain, belly, face, arms, and legs. Usually, between weeks 18 and 20, the procedure is carried out.
It is crucial to keep in mind that prenatal screenings only offer a preliminary diagnosis—they do not offer a conclusive one.
Diagnostic Tests for Prenatal Genetic Conditions
Types of Genetic Testing in Pregnancy
Prenatal diagnostic testing can verify whether the foetus has a genetic issue. In these procedures, cells from the placenta or amniotic fluid are removed, and their condition is examined. When there is a high probability of a genetic issue or when a screening test results are abnormal, diagnostic testing is usually advised.
The most common diagnostic tests include:
Amniocentesis: To take a sample of amniotic fluid from the amniotic sac, a needle is inserted through the mother’s skin into the uterus during this procedure. Usually, amniocentesis is carried out between weeks 16 and 20 of pregnancy.
Chorionic Villus Sampling (CVS): A small sample of placental cells is taken for this test. The healthcare provider may choose to put the needle into the vagina or abdomen, depending on the situation. Usually, between weeks 11 and 13, CVS is carried out during pregnancy.
The gathered samples are sent to a laboratory for examination, where a variety of diagnostic procedures, including microarray, conventional karyotyping, and fluorescence in situ hybridization (FISH), may be carried out. While some results could be available in as little as 72 hours, others might take several weeks.
Who Should Consider Genetic Testing in Pregnancy?
It is a personal choice to have prenatal genetic testing done. Speak with your healthcare practitioner if you are unsure. The outcomes may reveal vital details regarding the health of the foetus. As part of standard prenatal care, all pregnant patients are offered genetic screening by healthcare practitioners.
Families may decide to have diagnostic genetic testing done during pregnancy for the following reasons:
- Unusual findings from a genetic screening examination.
- A personal or family history of genetic disorders.
- The mother is older than 35.
- A history of stillbirth or miscarriage.
Test Details
Is Genetic Testing Necessary During Pregnancy?
Genetic testing relating to pregnancy is not necessary. It’s a personal decision influenced by your beliefs and medical history. Some parents choose to get tested to prepare for raising a child with a genetic condition, while others may need to make difficult decisions based on the test results. It is entirely up to you and your healthcare professional to decide whether to proceed with diagnostic testing or prenatal screening.
How is Genetic Testing in Pregnancy Conducted?
A pregnancy blood test is required for the majority of prenatal genetic testing. Your doctor can suggest more intrusive diagnostic procedures like amniocentesis or CVS if the results show a high chance of a congenital disease.
First Trimester Screenings
Screenings during the first trimester, such as the NT ultrasound, cell-free foetal DNA test, and serum test, are usually conducted between weeks 11 and 14. Assessing the risk for common chromosomal diseases like Down syndrome is made easier by combining the results of blood tests with ultrasound findings.
At any time throughout pregnancy, even as early as 6 to 10 weeks gestation, carrier testing can be performed. These assays detect single-gene disorders that may be inherited by the developing foetus. Carriers, however, are unable to identify diseases like Down syndrome that result from aberrant chromosomal numbers.
Second Trimester Screenings
Screenings for the second trimester take place between weeks 15 and 22 of pregnancy. These include the quad screen, which evaluates four proteins to determine the likelihood of genetic or physical abnormalities, and the maternal serum alpha-fetoprotein (AFP) screen. During this period, another screening technique is a foetal anatomy ultrasound.
Can Genetic Screenings Be Inaccurate for Down Syndrome?
A prenatal screening could potentially be erroneous at any time. Information regarding the accuracy rates of any screening tests conducted during pregnancy can be obtained from your healthcare provider.
Does Genetic Testing While Pregnant Come With Any Risks?
Prenatal tests are risk-free and only require a small blood sample. However there is a small increase in risk associated with diagnostic procedures like amniocentesis or CVS, including bleeding, infection, or miscarriage.
Results and Follow-Up
When Will I Receive My Test Results?
While the results of diagnostic testing can vary from several days to weeks, genetic screening test findings are typically available within a few days. The results will initially be given to your healthcare provider, who will then communicate them to you.
What Do the Results of Genetic Screening Tests Show?
Tests for genetic screening evaluate risk but do not offer a conclusive diagnosis. A positive result means that there is a greater chance of a genetic condition; a negative result means that there is a lesser chance. Your doctor might suggest additional diagnostic tests or put you in touch with a genetic counsellor to go over the findings and potential course of action.
Can Genetic Screening Tests Determine the Baby’s Gender?
Not only does cell-free DNA screening (NIPT) determine the likelihood of genetic disorders, but it can also reveal the sex of the foetus. Foetal sex may also be revealed by ultrasound. But the main goal of the test is not to determine foetal sex; rather, it is a secondary benefit.
At Risaa IVF, we prioritize the health and well-being of both mother and child. Our advanced genetic testing during pregnancy offers peace of mind by identifying potential genetic conditions early on. Contact us today!
