Stress during pregnancy is usually discussed in negative terms and fear and anxiety seem to be the rule in explaining its possible consequences. A recent and soon to be published study by Janet DiPietro suggests that, at least in part, the contrary may be true. DiPietro, an internationally recognized leader in the field of child development, is credited with having described for the first time the ontogeny of human fetal brain–behavior relations throughout gestation, the associations of maternal and fetal characteristics with the neurobehavioral maturation of the fetus, and the fetal neurobehavioral origins of individual differences in infant physiology and behavior. Her latest study shows that 2-week-old infants of women who experience relatively more stress during pregnancy showed faster neural conduction, “evidence of a more mature brain.” Thus, maternal stress during pregnancy may actually stimulate the unborn child’s brain development, suggesting that the dreaded nefarious effects of stress on the child may be simply a matter of degree.
In her other studies, DiPietro outlined evidence to support the notion that the effects of maternal stress on the unborn child are actually quite modest in magnitude, pointing out that the placenta breaks down the stress hormone cortisol in the woman’s blood, preventing most of it from reaching the fetus. However, she is also careful to note that maternal stress may directly influence the developing fetal nervous system; that these effects on brain development may be aggravated over time by various characteristics of postnatal development; and that existing research on the effects of maternal prenatal/perinatal stress on child development lacks conceptual and methodological consistency and scientific rigor.
Science writer Anne Murphy, author of the recently published new book Origins: How the Nine Months Before Birth Shape the Rest of Our Lives, classifies prenatal stress as belonging to the “profoundly unsatisfying” category of “it depends.” While describing her second pregnancy, Paul traces the developing literature on fetal origins, which has been called the staging ground for well-being and disease in later life. In her chapter on stress, she cites the existence of 200 industrial chemicals that can be found in babies’ umbilical cords, the link between low birth weight and later cardiovascular disease, and raises the possibility that a dietary supplement might one day protect future children from cancer.
Her focus on how expectant mothers can minimize harm to their unborn child during pregnancy makes Paul’s book a fascinating read that will help understand and put into perspective the opportunities and dangers of this fascinating period. It is the Stresshacker Recommended book for this week.