Shaping maternal physiology: Immune control of reproductive adaptation.

Pregnancy is one of the most extensive physiological transitions of adult life, requiring coordinated adaptation across virtually every maternal organ to support fetal growth while preserving maternal health. Although these changes have traditionally been viewed as endocrine driven, emerging evidence identifies the immune system as an active regulator of maternal physiology. The immune system is increasingly recognized as a broad regulator of host physiology, positioning it as a key driver of maternal adaptation. In this work, we discuss how pregnancy reprograms maternal immunity to orchestrate physiological reprograming of tissues. This framework shifts the view of maternal immunity from one centered on immune homeostasis and fetal tolerance to one in which immune cells actively instruct physiological short- and long-term adaptation across maternal organs to shape health beyond reproduction.