A new article in Ecological and Evolutionary Physiology examines how the immune system and reproduction interact in female mammals, especially during pregnancy, from mating to birth.
Lauren E. MacDonald, Chloe C. Josefson, Bethaney D. Fehrenkamp, and Teri J. Orr explore how this relationship evolved and its effects on survival in their paper, " Reproductive Immunology from Copulation to Parturition in an Evolutionary and Ecological Context ."
They find that reproductive success may depend as much on immune balance as biology, making the case for considering the immune system as a key player in reproductive strategy.
Unlike past papers that focused narrowly on humans or livestock, this paper draws on insights across diverse species—including bats, marsupials, and rodents—to uncover how immune systems have evolved to manage reproduction. "The intersection between the reproductive and immune systems is particularly dynamic," they write, pointing out cooperative interactions, such as when inflammation facilitates implantation and placentation, and opposing interactions, such as when the adaptive immune response is suppressed to avoid harm to the sperm."
The authors review literature showing how pregnancy is a biologically risky period, including how diseases might spread more easily in pregnant animals, and why reproductive failure is sometimes the result of immune miscommunication. The paper also highlights how different stages each require specific immune shifts. "Immune changes during reproduction are not always antagonistic, and immune defense isn't monolithic," they write. In the meantime, a strong immune defense may reduce reproductive success, while prioritizing reproduction can leave mothers vulnerable to infection.
There is a need for a female-centric approach to understand the true complexity of reproductive immunology, the authors posit, stating that most immunology studies are based on male physiology. "It is important to apply this female-centric perspective in future studies addressing the physiological, ecological, and evolutionary aspects of reproductive immunology," they write.
Ecological and Evolutionary Physiology primarily publishes original research examining fundamental questions about how the ecological environment and/or evolutionary history interact with physiological function, as well as the ways physiology may constrain behavior. For EEP, physiology denotes the study of function in the broadest sense, across levels of organization from molecules to morphology to organismal performance and on behavior and life history traits.
