New research findings suggest that stress during the first trimester of pregnancy alters the placenta’s protein content, which affects brain development. A research group at University of Pennsylvania School of Veterinary Medicine set search for a biomarker to explain the increased risk of schizophrenia for males born to women with heightened stress during pregnancy that had been observed in previous human studies. The research group, headed by Tracy Bale, performed an experiment producing stress for mice so as to compare placenta development. The placenta of male offspring showed lower levels of O-linked-N-acetylglucosamine transferase (OGT).
To examine the relationship between the gender discrepancy in OGT levels and brain development, the research team genetically altered OGT in a female mouse to be half that of a normal female mouse and discovered changes in over 370 genes that are instrumental to neurological development. Bale and her research team compared the OGT expression of mothers’ placentas after birthing males with that of the male side of the placenta, finding that the male side of the placenta had reduced OGT expression. This pattern in the OGT distribution of human placentas mirrors that found in the experiment with mice. The reaction of OGT expression to a mother’s stress during gestation may be a protective measure, but because males have less of the enzyme naturally the response increases risk of neurological complications. While OGT must still be confirmed as a biomarker for the relationship between prenatal stress and brain development in humans, this information may further prevention and early detection.