Prolactin's Role in Regulating Body Temperature During Pregnancy

Prolactin is widely recognized for its crucial functions in facilitating milk production and encouraging maternal caregiving behaviors. Recent research from the University of Otago—Ōtākou Whakaihu Waka has unveiled an additional vital role of prolactin: its involvement in controlling body temperature throughout pregnancy.

According to senior author Dr. Rosie Brown from the Department of Physiology, maintaining an appropriate body temperature is essential for maternal and fetal health, involving complex regulation by the central nervous system. The study, published in Cell Reports, demonstrates that prolactin acts within the hypothalamus—the brain's temperature regulatory center—to help manage core body temperature during gestation.

During early pregnancy, a woman's core temperature tends to rise rapidly, likely due to increased progesterone levels. As pregnancy progresses, metabolic heat production also increases owing to fetal growth, maternal tissue development, and higher food intake. Interestingly, in late pregnancy, the core temperature decreases, and researchers have now identified prolactin as a key hormone facilitating this heat loss, which is crucial for maternal and fetal well-being.

Dr. Brown emphasizes that this temperature regulation helps prevent hyperthermia—a condition that can adversely affect fetal brain development—and supports a safe environment for the fetus. This hormonal influence underscores how pregnancy involves intricate physiological adjustments driven by changes in hormone levels.

Furthermore, this discovery enhances understanding of how hormones like prolactin modify brain functions to promote survival. It also raises potential considerations for animal reproduction, especially in the context of climate change, as prolactin pathways might serve as adaptive mechanisms to environmental thermal challenges.

The research offers valuable insights into the biological processes during pregnancy and highlights prolactin’s dual role in supporting lactation and regulating body temperature to optimally support both mother and baby.