ANA Test in Pregnancy

One of the many factors involved in a woman’s ability to become pregnant as well as to maintain a pregnancy is a healthy and properly functioning immune system. The Antinuclear Antibody (ANA) test is given to help doctors identify problems with the immune system that might impact fertility.

Immune System and Pregnancy

The immune system is designed to detect and destroy foreign substances that enter the body. In order for a woman to maintain her pregnancy, it is necessary to fool the immune system into thinking that the fetus is not a potentially dangerous infection in need of removal. To protect the fetus from its own mother’s immune system, the developing fetus negotiates a complex relationship with the mother’s immune system, which prevents the mother from developing antibodies to her baby.

Autoimmune Disorders and Pregnancy

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An autoimmune disease occurs when the immune system becomes confused and generates antibodies that attack the cells of the body even though they are not foreign invaders. Women are much more likely than men to be diagnosed with an autoimmune disorder. In fact, diagnosis peaks during a woman’s childbearing years, which makes a certain amount of sense considering the stress that preparing for a potential pregnancy can have on the immune system. After all, the female immune system may be called upon at any time to change its rules and ignore what would otherwise be considered a foreign invasion in order to allow a pregnancy to begin and progress.

The ANA Test

Women who have been diagnosed with an autoimmune disorder tend to have persistent issues with becoming pregnant as well as maintaining a pregnancy. In fact, women who have not been diagnosed with an autoimmune disorder but who have experienced multiple miscarriages often test positive for some of the markers of autoimmune disorders. This has led to the use of the ANA test in women that have either had failed pregnancies or difficulty conceiving even if they do not display any other symptoms of autoimmune disease. The ANA test is a commonly used screen for autoimmune disorders, and works by detecting the presence of antinuclear antibodies, which are substances produced by the immune system that attack components of the patient’s own cells.

Interpretation of Results

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The absence of Antinuclear Antibody in the blood is a negative result and generally indicates that there is no autoimmune disorder present. Significant levels of ANA in the blood can indicate the presence of an autoimmune disorder. Lower level, but still positive results, can be obtained in a pregnant woman without other symptoms of autoimmune disease. This does not mean that she has or will develop a serious autoimmune reaction, but it can mean that the immune system has the potential to develop antibodies against a developing fetus, a situation that in the absence of treatment could result in the ending of the pregnancy. Low-level positive results in a woman who has recently experienced a miscarriage can be interpreted to mean that an autoimmune response might have been responsible for the ending of her pregnancy.


The ANA test is a valuable tool that can allow doctors to identify and address some underlying causes of infertility and identify women who may be at-risk for repeat miscarriage. If the ANA test is positive, further testing may be required to clarify immune status as well as determine the appropriate treatment course. A variety of treatment options exist that can maximize the probability of a successful pregnancy for women who have autoimmune issues. These treatments include the steroid prednisone, aspirin or the drug heparin, which is a commonly used blood thinner.