Everything You Need to Know About Routine Antenatal Screenings and Tests

Happy pregnant woman visit gynecologist doctor at hospital or medical clinic for pregnancy consultant. Doctor examine pregnant belly for baby and mother healthcare check up. Gynecology concept.

To ensure the health of both you and your unborn child, several standard prenatal screenings and tests are advised while you’re having a child. Prenatal screenings are performed to identify any potential health problems that would need to be watched during pregnancy. Prenatal exams performed regularly can also aid in identifying any potential issues that can occur during labor. Everything you need to know about prenatal screenings and tests is covered in this blog post.

Blood tests

One of the most popular prenatal screening procedures performed during pregnancy involves blood tests. These examinations are carried out to look for any potential problems that might be there, such as anemia, certain infections, and chromosomal abnormalities. Important details about a mother’s blood type, Rh factor, and other blood-related conditions can also be learned from prenatal screening tests. Here is the list of the various routine blood tests that are carried out during pregnancy along with the time when they are conducted:

  • Blood type and Rh status: done at the first prenatal visit
  • Haemoglobin and hematocrit: done at the first prenatal visit
  • Rubella immunity: done at the first prenatal visit
  • Hepatitis B surface antigen: done at the first prenatal visit
  • Syphilis: done at the first prenatal visit and again at 28 weeks
  • HIV: done at the first prenatal visit and again at 28 weeks
  • Varicella immunity: done at the first prenatal visit
  • Cytomegalovirus (CMV) and toxoplasmosis: done at the first prenatal visit if the woman is considered at high risk
  • Blood glucose (for gestational diabetes screening): done between 24 and 28 weeks
  • Anaemia screening: done between 24 and 28 weeks
  • Group B streptococcus (GBS) screening: done between 35 and 37 weeks

It is important for expecting mothers to understand the importance of prenatal screening and the various prenatal testing options available to them. Your healthcare provider will provide you with prenatal tests and a screening schedule that you should follow throughout your pregnancy. By having the necessary screenings and tests done throughout your pregnancy, you can ensure that your baby is healthy and that any potential issues are caught early on.

Ultrasounds

Ultrasound imaging is one of the most common prenatal screening tests used to monitor a baby’s development throughout pregnancy. It is a type of imaging that uses high-frequency sound waves to create images of the baby and its surrounding structures in the uterus. Ultrasound is an important part of prenatal testing options as it can be used to determine the baby’s position, age, size, and physical structure.

Ultrasounds are generally considered safe and painless, and they provide a lot of valuable information to healthcare providers. They can detect fetal anomalies and multiple pregnancies, evaluate placenta placement, estimate fetal weight, and assess amniotic fluid levels. It is also possible to identify some chromosomal disorders during an ultrasound.

The importance of prenatal screening tests cannot be overstated. Regular ultrasounds throughout pregnancy can provide important information about the health of both mother and baby, allowing healthcare providers to make informed decisions about care. A typical prenatal test and screening schedule might involve an ultrasound every four weeks from 18-20 weeks gestation, with additional ultrasounds as needed for women who have high-risk pregnancies.

Nuchal translucency scan

A nuchal translucency scan is a prenatal screening test that can detect genetic abnormalities in an unborn baby. It is an ultrasound that measures the back of the baby’s neck to check for any physical signs of Down syndrome, Edwards syndrome, or other chromosomal defects. This scan is done between 11 and 14 weeks of pregnancy and is commonly included as part of routine prenatal screening tests.

During this procedure, the doctor will measure the thickness of the nuchal fold (the collection of tissue behind the baby’s neck) with an ultrasound machine. The doctor will also measure the circumference of the baby’s head, abdomen, and femur (thighbone). The results are then used to calculate the baby’s risk of having a chromosomal abnormality. If a high risk is identified, additional testing may be recommended.

This is an important prenatal test because it is one of the most reliable methods to diagnose some serious genetic disorders early in pregnancy. This allows couples to decide if they want to continue the pregnancy or terminate it, as well as allows them to make more informed decisions regarding further prenatal testing options.

Amniocentesis

Amniocentesis is a medical procedure in which a small sample of the amniotic fluid surrounding the fetus is removed and analyzed. It’s typically recommended when there is a high risk of certain chromosomal or genetic conditions, such as Down syndrome, or when certain structural abnormalities are suspected.

Amniocentesis is usually performed between 15 and 20 weeks of pregnancy. It is usually recommended in the following cases:

  • If a woman is 35 or older at delivery
  • If a woman has a positive result on a screening test such as a first-trimester screen, integrated screen, or cell-free DNA test
  • If there is a family history of a chromosomal or genetic disorder
  • If a previous pregnancy was affected by a chromosomal or genetic disorder
  • If a structural abnormality was detected during ultrasound

It’s important to note that amniocentesis is an invasive procedure and carries a small risk of complications such as bleeding, infection, or miscarriage. Always consult with your healthcare provider to discuss the risks and benefits of the procedure and whether it is the right option for you.

Genetic analyses

Prenatal screening tests are used to determine the likelihood of genetic abnormalities in a developing fetus. Karyotyping, non-invasive prenatal testing, and chromosomal microarray are typical prenatal tests for genetic diseases.

Compared to karyotyping and microarrays, a more recent kind of test called non-invasive prenatal testing (NIPT) examines fetal DNA circulating in the mother’s blood. NIPT is often used to identify Down syndrome and other chromosomal abnormalities-related diseases. As compared to amniocentesis, NIPT is a less invasive option, as it does not require the removal of amniotic fluid from the uterus. It is also associated with a lower risk of miscarriage, as it is only a blood test.

NIPT is also able to detect a wide range of chromosomal abnormalities, not just the common ones like Down syndrome, Edwards syndrome, and Patau syndrome. However, NIPT is a screening test and not a diagnostic test, so if the results are positive, additional diagnostic testing, such as amniocentesis or chorionic villus sampling (CVS), is needed to confirm the results. Additionally, NIPT is not 100% accurate, so false positive or false negative results may occur.

Conclusion

Prenatal screening testing is of extreme importance during pregnancy. According to the American College of Obstetricians and Gynaecologists, every trimester of pregnancy should include at least one prenatal test or screening. This will provide you and your healthcare provider with the much-needed progress details of your baby’s growth and development. Additionally, it’s crucial to adhere to your prenatal testing schedule so that any problems or worries can be swiftly resolved.