Despite the lack of recent data, various research has indicated that Asian women are less likely to get prenatal testing compared to their other ethnic counterparts in western developed countries. However, Asian women are more likely to give birth to babies with genetic defects.
Prenatal testing broadly includes two kinds of tests carried out during pregnancy: the diagnostic test and the screening test. Both tests provide valuable information on the fetus’ health status. All parents wish for their newborns to be healthy and smiling, and as parents-to-be, there is a lot of anticipation for the arrival of your newborn including worries about their health.
This article will discuss the types of prenatal testing and questions that would come in handy if you are considering this option.
Two Types of Prenatal Testing
Our genetic material is organised into 46 different packages called chromosomes. Some people are born with different numbers of chromosomes, or their chromosomes might have deformities, which might negatively influence their learning and growth. A screening test aims to look for these abnormalities at the early stage of the pregnancy. The screening test consists of three parts.
- Combined first-trimester screening involves an ultrasound between 11 and 13 weeks of pregnancy and a blood test between 10 and 13 weeks of pregnancy. This screening can identify approximately 85% to 90% of babies with Down syndrome (a chromosomal defect where there are 3 copies of chromosome 21 instead of 2 copies) and other chromosomal defects.
- Cell-free DNA screening is a blood test done from 10 weeks of pregnancy onwards, to estimate the chance of Down syndrome. It can also detect a baby’s blood type and gender.
- Second-trimester serum screening is a blood test done between 15 and 20 weeks of pregnancy to detect Down syndrome.
Only a diagnostic test, such as an amniocentesis or chorionic villus sampling (CVS), can tell whether your baby has a genetic or chromosomal condition. Most people choose to have a screening test first before going through either one of the diagnostic tests as diagnostic tests carry a small chance of miscarriage.
- Amniocentesis is done between 15 and 20 weeks of pregnancy. The fluid surrounding the fetus is drawn out by an ultrasound-guided needle. The fluid at that stage contains many fetal cells and proteins. The genetic material in the fetal cells can be of diagnostic value to rule out potential genetic diseases. It can also test fetal lung maturity and provide forensic paternity testing.
- Chorionic villus sampling (CVS) is done between 10 and 13 weeks of pregnancy. An ultrasound-guided needle is inserted into the placenta to obtain a tissue sample. CVS has a similar function to amniocentesis. Although CVS can be done earlier than amniocentesis, it has a greater risk of miscarriage in general.
What are the Pros and Cons?
Like all other medical tests, prenatal testing has its pros and cons. On one hand, prenatal testing offers you peace of mind that your fetus is healthy. Also, knowing in advance about your baby can help you prepare if your baby has special needs. On the other hand, the screening test only gives you a possibility, in terms of percentage, of your baby having a certain genetic disease. This can bring unnecessary anxiety for the parents, which can have a negative hormonal influence on the baby.
Questions to Ask Yourself Before Deciding on the Test
To get you and your spouse to be mentally prepared, here are some very important questions to ask yourselves as parents-to-be.
- What will you do if the test shows your fetus has genetic conditions? Is abortion legal in your jurisdiction? Can you afford the treatment if the baby was to be born?
- How accurate is the result in your local lab or hospital? Can more tests be done to make the results more accurate?
- Knowing the risk of infection and miscarriage, are you mentally prepared for these to happen?
No jurisdiction in the world mandates prenatal testing, but some countries’ public health insurance covers the cost. It entirely depends on the parents to decide whether prenatal testing is the best option for them. Consult your doctor and discuss this with your family members. For parents-to-be, this is the first among so many life-changing decisions you will need to make for your children in the next few decades.