- Maternal immune system activation due to various factors during
pregnancy have been found to affect developing brain of the fetus
- Brain changes associated with maternal immune response persist into
toddlerhood with these babies found to have impaired mental and motor
of the maternal
immune system, especially during the third trimester might affect the developing
fetal brain, according to a team of scientists led by Bradley Peterson, MD,
director of the Institute for the Developing Mind in the Department of
Pediatrics at Children's Hospital Los Angeles. The study appears in the
Journal of Neuroscience.
immune system responds to several stimuli such as infections, stress, illness,
and allergies. Upon activation by various stimuli, proteins are released as
part of this immune/ inflammatory response. Studies in animals have shown that
certain proteins released during this response can affect offspring, but little
is known about the effect on humans.
‘Changes in fetal brain associated with maternal inflammation and immune response persist into toddlerhood as well’
current study was designed to find whether and how immune/inflammatory response
the developing brain of infants.
The study enrolled young women
in the second trimester of pregnancy with the following tests:
- Blood test and fetal heart
monitoring in the third trimester,
- Brain scans of the newborns, and
- Mental and motor development
assessment of the infants at 14 months of age
this novel prospective study, Peterson and his colleagues regularly monitored
babies from a critical point in fetal brain development in utero, then at
birth, and all the way into their second year. The aim was to determine the
existence of a possible link between fetal brain development and maternal
immune system activation during pregnancy, especially the third trimester.
Methods and Results of
- During their third trimester
maternal blood was obtained and tested for levels of IL-6 (interleukin-6)
and CRP (C reactive protein) - two acute phase proteins that are elevated
during activation of the inflammatory response
- The team also monitored fetal heart rate as a measure of nervous system development
the team found that CRP levels did
correlate with variations of the fetal heart rate
, which is in turn dependent on the nervous system,
suggesting that maternal inflammation during pregnancy may begin to impact
fetal brain development.
- When the babies were born, they
underwent MRI scans in their first few weeks of life, enabling the team to view the babies
nervous system development and possible influence of prenatal factors
MRI Imaging Finding of
Newborn - Disturbance in Salience Network
significant alteration in the connections between specific brain regions termed
salience network was noted to correlate with elevated maternal IL-6 and CRP
levels. The function of this network is to filter stimuli coming into the brain
and prioritize them on the basis of those which need immediate attention.
brain is constantly receiving information from our bodies and the external
world," explains Peterson, who is also the director of the Division of
Child and Adolescent Psychiatry and Professor of Pediatrics in the Keck School
of Medicine at USC. "The salience network sifts through that information
and decides what is important and warrants action."
in the normal function
of the salience network
shown to be associated with the development of autism
and psychiatric illnesses, such as schizophrenia
is the first study to study about a possible association between the effect of maternal
inflammation directly in the disruption of the salience network in infants.
Assessment of Mental
Development of the Babies at 14 Months
14 months of age, the babies were assessed for motor skills, language
development, and behavior following the guidelines of Bayley Scales of Infant and Toddler Development
found marked variations in the scores of toddlers whose mothers had elevated
IL-6 and CRP levels during pregnancy.
study suggests a possible association between maternal immune response and
fetal brain development and disorders such as autism spectrum disorders.
more work needs to be done to validate these findings and gain more insight.
To conclude in the words of Dr Petersen, "This finding fills in a missing
piece. Although studies in animals have suggested it, this study indicates that
markers of inflammation in a mom's blood can be associated with short- and
long-term changes in their child's brain, which will now allow us to identify
ways to prevent those effects and ensure children develop in the healthiest
possible way beginning in the womb and continuing through later childhood and
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