Essential Lab Tests in Second Trimester of Pregnancy

The second trimester of pregnancy is exciting—you can feel your baby move, and your bump becomes more visible.

With increased energy and reduced nausea, staying on top of prenatal care is essential. Important tests during this stage include triple marker - second trimester, glucose screening and blood tests for anaemia and infections, ensuring your and your baby's well-being.

Let us understand blood tests during pregnancy second trimester in detail.

The Maternal Serum Screening - Triple Marker test is a crucial prenatal screening tool typically performed between the 15th and 20th weeks of your second trimester. This simple blood test during pregnancy second trimester measures the levels of three specific substances in your blood: Alpha-Fetoprotein (AFP), Human Chorionic Gonadotropin (hCG), and Unconjugated Estriol (uE3).

Here's how the Maternal Serum Screening - Triple Marker test can benefit you:

• Early detection of genetic disorders: This test helps identify the risk of chromosomal abnormalities such as Down syndrome and Edwards syndrome, as well as neural tube defects like spina bifida, allowing for timely intervention and better management of your pregnancy.
• Non-invasive and affordable: As a non-invasive blood test, the triple marker test is an affordable, simple and safe procedure, making it accessible as part of your routine prenatal care.
• Comprehensive risk assessment: By analysing the levels of the three markers, you and your healthcare provider can make more informed decisions about the course of your pregnancy and offer appropriate counselling and support.

The Maternal Serum Screening - Quadruple Marker test is another essential prenatal screening tool performed during the second trimester, usually between weeks 15 and 20. This test expands upon the triple marker test by measuring an additional substance called Inhibin A with AFP, hCG, and uE3.

The benefits of the Maternal Serum Screening - Quadruple Marker test include:

• Enhanced accuracy: By incorporating the measurement of Inhibin A, the quadruple marker test provides a more accurate assessment of the risk for chromosomal abnormalities than the triple marker test alone.
• Comprehensive screening: This test screens for Down syndrome and Edwards syndrome and helps detect other chromosomal abnormalities and neural tube defects, giving you a complete picture of your baby's health.
• Peace of mind: Knowing the quadruple marker test results can provide reassurance or help you prepare for any potential challenges, allowing you to make informed decisions about your pregnancy and your baby's future.

Malaria remains a concern in parts of India, especially in forested tribal areas of Chhattisgarh, Andhra Pradesh, Madhya Pradesh and Telangana. While not as widespread as before, it still affects about 12% of pregnant women, with the parasite’s affinity for the placenta making first-time pregnancies more vulnerable.

Malaria during pregnancy can cause maternal anaemia, fetal growth retardation, preterm birth, low birth weight, miscarriages, and, in severe cases, maternal and foetal death. Early detection is key, and the Peripheral Smear for Malarial Parasite (MP) test is one of the most reliable diagnostic tools. It is advised only if medically indicated.

What is the MP Test?

The Peripheral Smear for Malarial Parasite (MP) test is a blood test that detects malaria parasites, identifies the type, and measures parasite load. It aids in early diagnosis and timely treatment.

How is the Test Done?

The MP test is quick and simple:

• A blood sample is drawn, usually from the arm.
• A drop is placed on a glass slide and stained.
• A lab technician examines it under a microscope to detect and identify the parasite.

What the Test Can Reveal

The MP test provides valuable insights, including:

• The presence of malaria parasites.
• The type of Plasmodium species (e.g., P. falciparum, P. vivax).
• The parasite density, which helps assess the severity of the infection.

Preparing for the MP Test

No special preparation is needed. You can eat and drink as usual before the test. Wear comfortable clothing that allows easy access to your arm.

The TB Gold test (Quantiferon) is an interferon-gamma release assay (IGRA) that screens for latent tuberculosis infection (LTBI) by measuring the immune system’s response to TB bacteria. This helps diagnose both latent and active TB infections.

Early detection of latent TB infection in the second trimester is crucial for preventing progression to active TB, which can lead to severe complications for both mother and baby. The test is particularly important for pregnant women at higher risk, such as those with weakened immunity or HIV, as they are more susceptible to TB progression during and after pregnancy.

This is not a routine test and is only done if medically indicated and advised by your healthcare provider.

Key features and benefits include:

• Simple blood sample collection process
• High sensitivity and specificity for detecting TB infection
• Results are available within a few days, allowing for prompt treatment if needed

Here's how the TB Gold test can benefit you during your second trimester:

• It requires only one visit to collect a blood sample, unlike the traditional tuberculin skin test (TST), which requires two visits.
• The results are objective and laboratory-based, reducing the subjective variation associated with the interpretation of tests.
• It is not affected by previous BCG vaccinations or exposure to non-tuberculosis mycobacteria, making it highly specific.
• Results are typically available within three to five business days, allowing for prompt action if needed.

Detecting and treating LTBI during pregnancy is crucial, as it can prevent the development of active TB disease, which can be harmful to both the mother and the baby. Active TB during pregnancy can lead to complications such as:

• Increased risk of miscarriage, preterm labour, and low birth weight
• Higher chances of congenital TB in the newborn
• Potential transmission of TB to the baby after birth

By incorporating the TB Gold test into your second trimester screening, you can take proactive steps to safeguard your health and the health of your growing baby. 

If any of your blood test results during pregnancy come back abnormal, try not to panic. An abnormal result doesn’t necessarily mean something is wrong with you or your baby. Sometimes, factors like medications, diet, or sample handling can influence test results.

The first step is to discuss your results with your healthcare provider. They will review the findings in the context of your overall health and pregnancy history. Depending on the specific abnormality, your provider may recommend additional testing, such as a repeat blood test or an ultrasound, to gather more information.

Abnormal results may require changes to your prenatal care plan, such as adjusting your diet, taking supplements, or monitoring your condition more closely. Your healthcare provider will work with you to develop an appropriate management strategy to ensure the best possible outcomes for you and your baby.