In September 2024 we so-sponsored a virtual meeting with Frontier Nursing University on Maternal Mortality. During this meeting data was presented on causes of mortality in the United States during the childbearing years and proven strategies that reduce high death rates. The underlying causes for the deaths were presented and discussed. Causes related to the mental health of the mother are suicide and substance abuse and are the most common reasons for deaths among white women. The black rates in this category are lower, but still considerable. The latest statistics available demonstrate that the rate of death due to mental health issues among non-hispanic whites is 36.4 and among non-hispanic blacks is 8.6. Clinical depression is the underlying condition leading to suicide while substance abuse is often related to depression although there are other factors involved. In discussing strategies to reduce maternal mortality, several nurse-midwives discussed ways to diagnosis clinical depression early in pregnancy and the postpartum period in order to initiate treatment before severe depression takes hold and thus prevent death. However, the fact remains that reproductive scientists understand very little about what happens to the brain during pregnancy and in the postpartum period (1). A pioneering study of brain changes during pregnancy and the postpartum period was recently published (2) -a first step in understanding the fundamental changes in the pregnant brain. Before sharing the important findings, I want to stress that this study lays the ground work for fully appreciating the neuroplasticity of the brain that occurs in gestation and during the year after birth. Future studies expanding the number of study subjects which will correlate the observed brain changes with clinical findings of pregnancy outcomes will lead to insights in understanding the cause of severe depression during the childbearing year. We know the physiological changes of pregnancy in other organ systems and it is now time to discover those changes in the brain. The scientists of the cited study looked at 26 serial MRI scans of a mother during her first pregnancy starting at 3 weeks before pregnancy, during pregnancy and through two years after birth. Grey matter volume and cortical thickness decreased during pregnancy and partially returned to baseline after birth. Gray matter is made up of neurons, synapses and glia cells which are in the cortex of the brain (the brain’s surface area). White matter is made of nerve fibers that function to transport signals between gray matter. The study found that the global microstructural integrity of the white matter increased in pregnancy but dropped after birth. The ventricle of the brain expanded with a increase in cerebral spinal fluid in the 2nd and 3rd trimesters and then dropped sharply after birth. The researchers correlated all scan findings with peripheral blood levels of hormones, estrogen and progesterone. Hormonal levels in blood throughout pregnancy and the postpartum period have been well documented for many years. These findings show clearly that there is considerably plasticity of the brain during this timeframe. Mothers have written about having intrusive thoughts and forgetfulness and insomnia (2) and have wondered “What was happening”. Brain networks reorganize and adapt and now scientists can design further studies to understand both the usual situation and alterations of brain changes that might help to understand what happens in depressive states throughout the childbearing year. This information obtained will be helpful in making policy decisions that will prevent a good portion of maternal deaths. (3) Some of these policy initiatives are integration of perinatal and mental health care; the addition of reproductive psychiatry to medical, nurse-midwifery and nursing curricula, and providing social foundations that strengthen families now and in future generations. References:
1. Pritschet, L., Taylor, C.M., Cossio, D. et al. Neuroanatomical changes observed over the course of a human pregnancy. Nat Neurosci 27, 2253–2260 (2024). https://doi.org/10.1038/s41593-024-01741-0.
2. Maxwell AM. What happens to the brain during pregnancy? J Clin Invest. 2024 Jul 15;134(14):e183888. doi: 10.1172/JCI183888. PMID: 39007265; PMCID: PMC11245145.
3. Wisner KL, Murphy C, Thomas MM. Prioritizing Maternal Mental Health in Addressing Morbidity and Mortality. JAMA Psychiatry. 2024 May 1;81(5):521-526. doi: 10.1001/jamapsychiatry.2023.5648. PMID: 38381408.