What are the key factors that contribute to the immunology of pregnancy and how do they impact the health and development of the mother and fetus?

During pregnancy, the mother's immune system undergoes changes to tolerate the fetus, which is genetically different. Key factors include hormonal changes, immune cell regulation, and the placenta's role in immune tolerance. These factors help prevent rejection of the fetus while protecting against infections. Imbalances in immune regulation can lead to complications like preterm birth or preeclampsia, affecting both the mother and fetus.