Inadequate nutrition during early pregnancy impairs fetal brain development, according to a new animal study [Proceedings of the National Academy of Sciences, 108 (7): 3011-16]. Researchers found decreased formation of cell-to-cell connections, cell division, and amounts of growth factors in the fetuses of baboon mothers fed a reduced diet during the first half of pregnancy.
"Our collaboration allowed us to determine that the nutritional environment impacts the fetal brain at both the cellular and molecular levels," said Laura Cox, PhD, an associate scientist at Texas Biomed, formerly the Southwest Foundation for Biomedical Research. "We found dysregulation of hundreds of genes, many of which are known to be key regulators in cell growth and development, indicating nutrition plays a major role during fetal development by regulating the basic cellular machinery."
The study involved scientists at the Southwest National Primate Research Center of Texas Biomedical Research Institute, the University of Texas (UT) Health Science Center at San Antonio, and Friedrich Schiller University in Jena, Germany.
The team compared two groups of baboon mothers, one eating as much as they wanted during the first half of pregnancy and the other receiving 30 percent less food, a level of nutrition similar to what many prospective mothers in the United States experience. The brain developmental stages of the nonhuman primate model are close to those of human fetuses. Most previous research in this area was conducted in rats.
"This study is a further demonstration of the importance of good maternal health and diet," said senior author Thomas McDonald, PhD, of the UT Health Science Center. "It supports the view that poor diets in pregnancy can alter development of fetal organs, in this case the brain, in ways that will have lifetime effects on offspring, potentially lowering IQ and predisposing to behavioral problems."
While marked nutrient restriction is known to adversely affect development of the fetal brain, Dr. McDonald said the study "is the first demonstration of major effects caused by the levels of food insecurity occurring in sections of U.S. society and demonstrating the fetus's vulnerability to moderate reduction in nutrients."
Researchers now must review the common notion that the mother is able to protect the fetus from dietary challenges such as poor nutrition during pregnancy.
"This is a critical time window when many of the neurons and supporting cells in the brain are born," said Peter Nathanielsz, MD, PhD, director of the Center for Pregnancy and Newborn Research in the Health Science Center School of Medicine.
In teenage pregnancy, he noted, the developing fetus is deprived of nutrients by the needs of the growing mother. In pregnancies late in reproductive life, a woman's arteries are stiffer, and the blood supply to the uterus decreases, inevitably affecting nutrient delivery to the fetus. Diseases such as preeclampsia or high blood pressure in pregnancy can lead to decreased function of the placenta, with decreased delivery of nutrients to the fetus.
Developmental programming of lifetime health has been shown to play a role in later development of obesity, diabetes and heart disease. This new finding provides impetus for researchers to look into the effects of developmental programming in the context of autism, depression, schizophrenia, and other brain disorders.
The study was funded by the National Institutes of Health and the German Federal Ministry of Education and Research.