Why did pregnancy trigger my hypothyroidism?
Natural immune shifts during pregnancy, together with a genetic tendency and other predisposing factors, can trigger hypothyroidism in some women.
Hypothyroidism is an immune disease for most
For 90 percent of Americans, hypothyroidism is caused by Hashimoto’s, an autoimmune disease in which the immune system attacks and destroys the thyroid gland.
The immune system has two major arms of function, one that reacts immediately to an invader, and one that reacts later to produce antibodies. When one of these arms of becomes overly dominant it can trigger an autoimmune disease.
Going into pregnancy predisposed
Pregnancy and the postpartum periods naturally polarize the immune system. In the third trimester the delayed immune response is dominant. Postpartum the immediate immune reaction is stronger.