Nature Neuroscience | Volume 27 | November 2024 | 2253–2260
 2253
nature neuroscience
https://doi.org/10.1038/s41593-024-01741-0
Resource
Neuroanatomical changes observed over the 
course of a human pregnancy
Laura Pritschet    1 , Caitlin M. Taylor    1, Daniela Cossio    2, 
Joshua Faskowitz    3, Tyler Santander1, Daniel A. Handwerker    3, 
Hannah Grotzinger1, Evan Layher1, Elizabeth R. Chrastil    2,5  & 
Emily G. Jacobs    1,4,5 
Pregnancy is a period of profound hormonal and physiological changes 
experienced by millions of women annually, yet the neural changes 
unfolding in the maternal brain throughout gestation are not well studied 
in humans. Leveraging precision imaging, we mapped neuroanatomical 
changes in an individual from preconception through 2 years postpartum. 
Pronounced decreases in gray matter volume and cortical thickness were 
evident across the brain, standing in contrast to increases in white matter 
microstructural integrity, ventricle volume and cerebrospinal fluid, with 
few regions untouched by the transition to motherhood. This dataset serves 
as a comprehensive map of the human brain across gestation, providing an 
open-access resource for the brain imaging community to further explore 
and understand the maternal brain.
Worldwide, nearly 85% of women experience one or more pregnancies 
in their lifetime1, with 140 million women becoming pregnant each 
year. Over an approximately 40-week gestational window, the maternal 
body undergoes profound physiological adaptations to support the 
development of the fetus, including increases in plasma volume, meta-
bolic rate, oxygen consumption and immune regulation2. These rapid 
adaptations are initiated by 100-fold to 1,000-fold increases in hormone 
production, including estrogen and progesterone. These neuromodu-
latory hormones also drive significant reorganization of the central 
nervous system. Evidence from animal models and human studies con-
verge on pregnancy as a period of remarkable neuroplasticity3–10 (see  
ref. 10 for one of the earliest known observations). Gestational increases 
in steroid hormone synthesis drive neurogenesis, dendritic spine 
growth, microglial proliferation, myelination and astrocyte remodeling  
(for review, see ref. 11). These cellular changes are pronounced in brain 
circuits that promote maternal behavior. For example, Ammari et al. 
recently discovered that steroid hormones can fine-tune the response 
properties of galanin neurons in the rodent medial preoptic area of 
the hypothalamus (mPOA), leading to enhanced sensitivity in dams 
to sensory cues from newborn pups12.
In humans, reductions in gray matter volume (GMV) have 
been observed postpartum 13–16, particularly in regions central to 
theory-of-mind processing 13. These GMV changes persist at 6 years 
postpartum17 and are traceable decades later 18,19, underscoring the 
permanence of this major remodeling event. And yet the changes that 
occur within the maternal brain during gestation itself are virtually 
unknown (see ref. 20 for early neuroimaging insight). A recent study by 
Paternina-Die et al. offers intriguing clues21. Women were scanned once 
in the third trimester and again in the postpartum period, revealing a 
reduction of cortical volume observable in the late pregnancy scan. 
These findings suggest that pregnancy is a highly dynamic period for 
neural remodeling, yet neuroscientists lack a detailed map of how the 
human brain changes throughout the gestational period.
Here we conducted a precision imaging study of pregnancy in 
which a healthy 38-year-old primiparous woman underwent 26 mag-
netic resonance imaging (MRI) scans and venipuncture beginning 
3 weeks preconception through 2 years postpartum. We observed 
widespread reductions in cortical GMV and cortical thickness (CT) 
occurring in step with advancing gestational week and the dramatic 
rise in sex hormone production. Remodeling was also evident within 
Received: 23 August 2023