Pregnancy and the postpartum period are a “very vulnerable time for mental disorders,” according to Henry A. Nasrallah, MD.
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“Those changes that are helping pregnancy can also have psychiatric and psychopathological implications,” Dr. Nasrallah said in a virtual meeting presented by Current Psychiatry and the American Academy of Clinical Psychiatrists.
Dr. Henry A. Nasrallah
Numerous dramatic changes in physiology, immune functions, cognition, neuroplasticity, and behavior occur during pregnancy, noted Dr. Nasrallah of the University of Cincinnati. For example, the volume of the brain actually decreases during pregnancy, but brain size recovers over the 6 months after delivery. “Clearly, this is a transitional and a transient phenomenon,” he said. “The decrease in brain volume is associated with changes in brain metabolism and an increase in intracellular pH after delivery.”
But these changes can also carry risks for psychiatric disorders, Dr. Nasrallah explained. Changes in the hippocampus, which is “very plastic throughout adulthood,” have been linked to aging, cognition, pregnancy, and motherhood. “The hippocampus is the ‘Grand Central Station’ of memory in the brain, and the hippocampus is affected by neurodegenerative and psychiatric disorders, which disproportionately affect women,” he said at the meeting, presented by Global Academy for Medical Education.
Dr. Nasrallah said the hippocampus has particular susceptibility during pregnancy and in the postpartum period, or in women who have previously been pregnant.
Gender of the fetus can even affect the health of the mother, he added. In women who are pregnant with male fetuses, working memory and spatial ability are higher than in women who are pregnant with female fetuses, Dr. Nasrallah said. This is tied to higher numbers of proinflammatory cytokines present in male fetuses. In female fetuses, there are lower levels of interferon-gamma and interleukin (IL)-12 in the first trimester, and higher levels of IL-1 beta, tumor necrosis factor B, IL-5, and IL-10 in the second trimester.
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“Cytokine interleukin-10 and interleukin-6 are both increased during psychosis and during depression, so you can see the vulnerability for developing postpartum depression.” Some women “have other genes that make them susceptible for mood disorders, and the pregnancy can push them over the edge,” he said.
If women have bipolar disorder prior to delivery, “they have a very high risk of postpartum depression, possibly because of this immune dysregulation that serves the pregnancy, but unfortunately makes the woman vulnerable for postpartum psychiatric disorders,” Dr. Nasrallah said.
The effects of having children extend into middle age, Dr. Nasrallah said. Research has shown giving birth to more than one to two children can affect a woman’s risk for Alzheimer’s disease and risk for early-onset of the disease. Women who have three or fewer children later in life are also more likely to live longer, he said. In general, a longer reproductive period, duration of breastfeeding, and low number of pregnancies result in better cognition, while younger age at first pregnancy leads to worse cognition.
So-called pregnancy brain causes some cognitive functions to decline, and women may experience trouble concentrating and memory disturbance. “Other functions increase for the sake of the baby,” including a high reaction to threatening stimuli, absent-mindedness, motivation, reward, fear, executive functions, social cognition, salience, and attachment, Dr. Nasrallah said. In some cases, hormone-driven remodeling of the maternal brain can cause postpartum psychosis, which can reduce the anterior cingulate cortex, left parahippocampal gyrus volume, and left superior temporal gyrus volume.
Most changes in the brain, however, appear to be temporary, Dr. Nasrallah noted. Executive function improves 2-6 months after delivery, which includes goal and directed behavior, working memory, inhibitory function, and cognitive flexibility. In the postpartum period, “the gray matter increases in the first 3-4 months, especially in the brain areas that are involved in maternal behavior that includes amygdala, hypothalamus, and prefrontal cortex,” he added. “All of those changes correlate with positive maternal attachment, and so that makes it easier for the mother to bond with the baby.
“Don’t think of it as a negative,” he said. “The decline in brain volume is actually associated with better mothering and increased attachment between the mother and the baby, which is vital for survival of the baby.”
Global Academy and this news organization are owned by the same parent company. Dr. Nasrallah reports no relevant financial disclosures.