“Stanford is a terrific place to do this work, because I can draw upon the strengths in basic science programs such as neuroscience and developmental biology at the School of Medicine, as well as the clinical expertise in neonatology at Packard Children’s Hospital.”
- Anna Penn, MD, PhD
Research about placenta's role may help premies
Throughout pregnancy, a mother’s placenta surrounds her baby with life-giving nutrients and hormones that help the fetus develop into a healthy newborn. Infants born prematurely, however, lose the full benefit of this organ and can face serious complications. For reasons not fully understood, infants born before 28 weeks gestation are at high risk for neurological difficulties, often causing them to lag behind their peers in brain development well into childhood.
Packard neonatologist Anna Penn, MD, PhD, wants to understand why. In collaboration with fellow faculty members in Stanford’s Neuroscience Institute, Penn is using her background in developmental biology to find ways to nurture brain development in preemies. Their work spans fields as diverse as neurosurgery, computer science, maternal-fetal medicine, and biology.
Penn is investigating why boys have poorer neurodevelopmental outcomes than girls following premature birth. Her team has found that newborn male mice exposed to abnormally low levels of oxygen lose greater brain volume than newborn females under the same conditions. The hippocampus, a brain region critical for learning and memory, showed the greatest sex-linked difference. Penn is now studying the role of sex steroids, to which the brain is exposed in high amounts during fetal development, in long-term anatomical and behavioral changes.
In addition, Penn is studying how placental estrogen, progesterone and testosterone affect fetal brain development. She suspects that preemies’ early disconnection from the placenta deprives them of hormonal cues that guide key aspects of brain maturation. Understanding this aspect of development may eventually make it possible to replace the missing hormones after birth, Penn says.