Tuberculosis (TB) is a bacterial infection that primarily affects the lungs but can spread to other body parts. Concerns about medical interventions, including diagnostic tests and vaccinations, are common for pregnant individuals. Understanding TB and its potential interactions with pregnancy is important for informed health decisions.
Understanding Tuberculosis in Pregnancy
Tuberculosis can manifest in two main forms: latent TB infection (LTBI) and active TB disease. With latent infection, the bacteria are present in the body but remain inactive, causing no symptoms and not spreading to others. In contrast, active TB disease means the bacteria are multiplying, leading to symptoms and the potential for transmission.
Active TB during pregnancy can negatively impact both the pregnant individual and the developing fetus. Untreated active TB is associated with increased risks of premature birth, low birth weight, and, in rare instances, congenital TB in the infant. The physiological changes of pregnancy, such as an increased respiratory rate and fatigue, can sometimes mask the symptoms of early TB, potentially delaying diagnosis.
TB Testing During Pregnancy
Testing for tuberculosis infection during pregnancy is performed using methods that include the Tuberculin Skin Test (TST), also known as the Mantoux test or PPD test, and Interferon-Gamma Release Assays (IGRAs). The TST involves injecting a small amount of purified protein derivative (PPD) into the skin, which is then observed for a reaction after 48 to 72 hours. IGRAs are blood tests, such as the Quantiferon-TB Gold test, that measure immune response to TB bacteria.
Both TSTs and IGRAs are considered safe for use during pregnancy and do not pose a risk to the fetus. Healthcare providers typically recommend these tests for pregnant individuals who have specific risk factors, such as recent exposure to someone with active TB, a weakened immune system, or residence in an area where TB is common. A positive test result indicates TB infection, prompting further evaluation, including a chest X-ray with abdominal shielding, to rule out active disease.
TB Vaccination for Pregnant Individuals
The Bacillus Calmette-Guérin (BCG) vaccine protects against severe tuberculosis, especially in infants and young children in prevalent regions. This vaccine contains a weakened, live form of the Mycobacterium bovis bacterium. It is administered as a single injection, typically into the skin.
Current guidelines generally do not recommend BCG vaccination during pregnancy because it is a live vaccine. The use of live vaccines during pregnancy is usually avoided due to a theoretical risk to the developing fetus. In most contexts, the benefits of BCG vaccination do not outweigh these potential risks for pregnant individuals. If a pregnant individual is eligible for BCG vaccination, it is typically advised to receive it after delivery.
Treating TB Infection During Pregnancy
When tuberculosis infection or disease is diagnosed during pregnancy, treatment is carefully managed to protect both the pregnant individual and the fetus. For active TB disease, treatment should begin immediately, as the risks of untreated TB outweigh the risks associated with the medications. Standard treatment regimens often involve a combination of drugs such as isoniazid, rifampin, and ethambutol. Streptomycin, however, is generally avoided due to potential harmful effects on the fetus.
For latent TB infection, treatment can often be delayed until after delivery, particularly if the pregnant individual has no additional risk factors for progression to active disease. However, if there are high-risk factors, such as HIV co-infection or recent close contact with an active TB case, treatment may be initiated during pregnancy. Isoniazid is a common treatment for latent TB in pregnancy, and it is typically given with pyridoxine (vitamin B6) to reduce potential side effects. All treatment decisions are individualized and made in consultation with healthcare providers to ensure the safest and most effective approach.