Which statement best describes Th1 and Th2 balance during pregnancy?

Which statement best describes Th1 and Th2 balance during pregnancy?

• A. Th2 anti-inflammatory increases to enhance antibody-mediated immunity; Th1 pro-inflammatory decreases
• B. Th1 increases to boost cell-mediated immunity
• C. No change in Th1/Th2 balance
• D. Th2 decreases and Th1 increases

Answer: (A)

During pregnancy, the maternal immune system shifts toward Th2-type, anti-inflammatory responses to tolerate the fetus. Th2 activity rises to support humoral immunity, while Th1 pro-inflammatory activity declines to lessen inflammatory cell–mediated reactions. This combination best describes the protective bias needed in pregnancy. If Th1 activity increased or if there were no change, inflammation could threaten fetal tolerance, which is not consistent with the maternal immune adaptation during pregnancy.

During pregnancy, the maternal immune system shifts toward Th2-type, anti-inflammatory responses to tolerate the fetus. Th2 activity rises to support humoral immunity, while Th1 pro-inflammatory activity declines to lessen inflammatory cell–mediated reactions. This combination best describes the protective bias needed in pregnancy. If Th1 activity increased or if there were no change, inflammation could threaten fetal tolerance, which is not consistent with the maternal immune adaptation during pregnancy.