Giving birth to a new brain: hormone exposures of pregnancy influence human memory.

Mammalian pregnancy produces alterations in maternal physiology that are necessary for maintaining gestation, fetal development and parturition. These changes also may prepare the maternal brain for the unique demands of motherhood. Parous rodents exhibit long-term changes in neurological structure and function and human work suggests that other landmark events in the reproductive cycle, such as menarche and menopause, influence cognition. However, the influence of pregnancy on the human brain remains to be elucidated. This study indicates that verbal recall memory (but not recognition or working memory) diminishes during human pregnancy and that these decrements persist after parturition. Further, prenatal glucocorticoids and estrogen are associated with these alterations. To meet the challenges of motherhood, the female brain may be remodeled, a process that appears to be initiated prenatally. However, it is not often that adaptation is achieved without an associated cost. For the human, in the case of the new maternal brain, diminished memory performance may reflect such a cost.