Second Trimester Pregnancy Tests

The second trimester of pregnancy, spanning from the 13th to the 26th week, is a critical phase in foetal development and maternal health. Getting routine blood tests done during the second trimester of one’s pregnancy is not only helpful in checking the growth of the baby but also in diagnosing and mitigating any potential risks and disorders.  

Second Trimester Pregnancy Tests 

 The second trimester of pregnancy is a period that typically begins around the 13th week and extends until the 26th week. This phase is more comfortable for the mother as it brings relief from the discomforts of the first trimester, such as morning sickness and fatigue, while the more challenging symptoms of the third trimester are yet to emerge.  

During this time, the developing foetus undergoes significant growth and development. The foetus becomes more active, and expectant mothers can often feel the baby's movements. The foetus’ development during this period includes the following:  

• The baby's bones start to harden, and their vital organs continue to mature. 
• The placenta develops fully. 

• The fingers and toes become fully separated and the nails start to grow 
• The baby starts to grow hair on its head 
• The brain further develops and the baby can respond to certain stimuli.  

By the end of the second trimester, most of the baby's major systems, including the respiratory and digestive systems are functional to some extent. 

As for the mother, proper nutrition and regular exercise become increasingly important during this period. Many women experience a boost in energy during the second trimester, making it an ideal time to tackle necessary preparations for the baby's arrival. The usual symptoms during this period include: 

• Increase in appetite. 
• The pregnancy becomes more visible as the foetus grows.  
• Mothers may experience weight gain and frequent backaches. 
• Mothers may experience a creamy white coloured vaginal discharge. 

 It is vital to remain vigilant about potential complications. High blood pressure, gestational diabetes, and other issues can arise, making regular prenatal check-ups essential. Many mothers opt for a blood test during the second trimester of their pregnancy to screen for various conditions and birth defects. Any unusual symptoms, such as severe abdominal pain or vaginal bleeding, should be promptly reported to a healthcare professional.  

Importance of Second Trimester Screening 

Prenatal screening and tests during the second trimester of one’s pregnancy hold immense importance for many reasons. It plays a pivotal role in ensuring both the well-being of the baby and the expectant mother. Typically performed between the 15th and 20th weeks of one’s pregnancy, these tests offer a window of opportunity to potential issues and conditions that may impact the developing foetus.  

One of the primary reasons for getting tests done in the second trimester is to assess the risk of abnormalities, most notably Down syndrome, Trisomy 18 and open neural tube defects. 

• Open Neural Tube Defects: 

Neural tube defects are conditions in which the baby's spinal cord, brain, or related structures do not form correctly. Diagnostic procedures such as ultrasound imaging and pregnancy tests during second trimester provide more detailed information about the baby's condition, helping parents and healthcare providers make informed decisions about potential treatments.  

• Trisomy 18: 

Trisomy 18, is a rare condition that can cause growth delays and intellectual disabilities. Early detection of this condition through second trimester screening tests can help doctors to plan for appropriate treatment plans and support systems.   

• Down Syndrome: 

Tests done during the second trimester of one’s pregnancy can also help in an early diagnosis of Down syndrome. Down syndrome is a condition that leads to developmental and intellectual challenges in humans. Detecting it early allows parents to prepare for potential challenges and make informed decisions about their baby's care and future. 

What does the Second Trimester Screening include? 

The second trimester is a crucial period marked by various screenings. Such screenings are designed to provide valuable insights into how the pregnancy is progressing and potential issues or conditions that may arise.  

 The various types of tests and why they are performed are as follows: 

• Multiple Marker Screening: 

This blood test analyzes specific substances in the mother's blood, including Alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and estriol. Elevated or decreased levels of these markers can indicate an increased risk of chromosomal abnormalities or neural tube defects.  

• Ultrasound: 

An ultrasound scan during the second trimester provides detailed images of the baby's anatomy. It can help identify physical anomalies, measure fetal growth, and estimate the gestational age.  

• Glucose Screening: 

This test assesses the mother's blood sugar levels to detect gestational diabetes. High blood sugar during pregnancy can lead to complications for both the mother and the baby. 

• Amniocentesis: 

This test is done to check for any genetic disorders or neural tube defects. It takes a sample of the amniotic fluid that contains the baby in the womb.  

Some other types of screening tests that may be required are tests for: 

• High blood pressure 
• Thyroid  
• Hepatitis C 
• Tuberculosis 

While a lot of expectant mothers order at-home blood tests during their second trimester of pregnancy to avoid fatigue and chances of infections, tests such as ultrasounds and Amniocentesis need to be done at the hospital.  

Results + Next Steps 

The results of second trimester screening tests can evoke a range of emotions for expectant parents. It's important to remember that these tests are not definitive diagnoses but rather indicators of potential risks. Understanding what the results may mean, consulting with one’s healthcare provider, and taking appropriate next steps is crucial during this phase of pregnancy. 

• Normal Results:  

If the results indicate that the baby has a low risk of abnormalities or neural tube defects, it can be a relief. However, it's important to continue with regular prenatal care and follow one’s doctor’s advice to monitor the pregnancy's progress. 

• Abnormal AFP Results: 

Alpha-fetoprotein (AFP) is a protein produced by the baby's liver that enters the mother's bloodstream. Elevated AFP levels do not always indicate any abnormalities in the baby and could sometimes also be caused if one is having twins or is further along in the pregnancy. However, it is routine to prescribe multiple tests of the AFP blood test in the second trimester to rule out complications. If levels are elevated after repeated tests, then more investigation may be required.  

It is essential to discuss one’s reports with a healthcare practitioner. They will be able to explain the findings, what they mean, and the potential implications for the well-being of both mother and child.