How does the immune system adapt to pregnancy?

How does the immune system adapt to pregnancy?

• A. Immunosuppressive effects due to cytokines, prostaglandin E2, steroid hormones, estrogen, and hCG
• B. Immune system remains unchanged
• C. Immune system becomes hyperactive
• D. No immune changes occur

Answer: (A)

Pregnancy requires the maternal immune system to tolerate the fetus, which carries paternal antigens, without shutting down overall defense. This adaptation is driven by immunomodulatory signals from cytokines, prostaglandin E2, and steroid hormones including estrogen and other hormones like hCG. Together, these factors create a tolerogenic environment that promotes regulatory T cells and a shift toward anti-inflammatory (often Th2-skewed) responses, dampening cytotoxic and inflammatory pathways while still allowing protection against infections. This balance prevents fetal rejection while maintaining safety against pathogens, rather than a blanket suppression or no change in immune activity.

Pregnancy requires the maternal immune system to tolerate the fetus, which carries paternal antigens, without shutting down overall defense. This adaptation is driven by immunomodulatory signals from cytokines, prostaglandin E2, and steroid hormones including estrogen and other hormones like hCG. Together, these factors create a tolerogenic environment that promotes regulatory T cells and a shift toward anti-inflammatory (often Th2-skewed) responses, dampening cytotoxic and inflammatory pathways while still allowing protection against infections. This balance prevents fetal rejection while maintaining safety against pathogens, rather than a blanket suppression or no change in immune activity.