Nature Neuroscience | Volume 27 | November 2024 | 2253–2260
 2255
Resource https://doi.org/10.1038/s41593-024-01741-0
Discussion
Converging evidence across mammalian species points to pregnancy 
as a remarkable period of neuroplasticity, revealing the brain’s ability 
to undergo adaptive, hormonally-driven neuroanatomical changes 
beyond adolescence13–15,20,21,24–26. Investigations that compare women 
prepregnancy and then again postpartum provide the strongest evi-
dence to date that the human brain undergoes such neural changes11,27. 
But what about pregnancy itself? Over what time course do anatomical 
changes in the maternal brain manifest? Are they tied to the substantial 
increase in sex hormone production? Here we begin to address these 
Pregnancy stages Sex steroid hormones
Progesterone ng ml–1
17β-estradiol pg ml –1
12,500
10017β-estradiol
Progesterone
Pre 1st 2nd 3rd Post
<0 0–13 14–26 27–40 >40
Gestation weeks
a b
Weeks since conception
00
Birth
–1 10 20 30 40 50
Study overview
/ /
Whole-brain T1
MTL scan
Diﬀusion MRI
Blood serum
Pre/IVF Pregnancy Birth Postpartum
c
0 14 27 40 60 93 162
Weeks since conception
Summary brain measures
GMV
(×10 5  mm 3 )
CT
(×10 6  mm) 
Brain vol
(×10 6  mm 3 )
Global quant.
anisotropy
Lat ventricles
(mm 3 )
CSF
(mm 3 )
d
Weeks since conception Weeks since conception
4.60
1.80
1.60
1.29
1.27
4.80
0 50 100 150
0 50 100 150
0 50 100 150
24,500
26,000
0.44
0.38
4,800
3,900
R2
adj  = 0.79, P < 0.001
R2
adj  = 0.50, P = 0.007
R2
adj  = 0.77, P < 0.001
R2
adj  = 0.91, P < 0.001
R2
adj  = 0.75, P < 0.001
R2
adj  = 0.90, P < 0.001
Birth Birth
0 50 100 150
0 50 100 150
/ /
/ /
/ /
0 50 100 150
0
Fig. 1 | Precision imaging reveals neuroanatomical changes throughout 
gestation. a, Standard medical demarcations for pregnancy stages (that is, 
trimesters) by gestation week (the image is created with BioRender.com).  
b, Steroid hormones increased significantly throughout pregnancy and dropped 
precipitously postpartum, as is characteristic of the prenatal and postnatal 
periods. c, A healthy 38-year-old primiparous woman underwent 26 scanning 
sessions from 3 weeks preconception through 2 years postpartum. Scans were 
distributed throughout preconception (four scans), first trimester (four scans), 
second trimester (six scans), third trimester (five scans) and postpartum  
(seven scans); tick marks indicate when major measures were collected and 
colors denote pregnancy stage. The participant underwent IVF to achieve 
pregnancy, allowing for precise mapping of ovulation, conception and gestation 
week. d, Summary (that is, total) of brain measures throughout the experiment. 
Generalized additive models revealed GMV, CT and total brain volume decreased 
throughout pregnancy (see Methods for validation with cubic regression), with 
a slight recovery postpartum. Global QA, lateral ventricle and CSF volumes 
displayed nonlinear increases across gestation, with a notable rise in the second 
and third trimesters before dropping sharply postpartum. Shaded regions 
represent 95% confidence bands; solid lines indicate model fit; dashed line 
indicates parturition.