As a mother of five, I feel like each pregnancy changes my state of mind. Now, a new study from the University of California, Santa Barbara, published in the journal Nature Neuroscience , confirms that I may have been right.
The researchers looked at the brains of 38-year-old healthy first-time mothers during pregnancy and for two years after giving birth. They performed 26 MRI scans and blood tests. They compared what they saw with eight that they didn’t expect.
Researchers have discovered that the brain undergoes a variety of changes during pregnancy, and here’s what they mean:
The pregnancy brain
In the new study, co-author PhD student Laura Pritchett and her team found that pregnant women’s brains experience a decrease in gray matter from about the ninth week of pregnancy throughout their pregnancy, along with increases in estrogen and progesterone.
Grey matter, also known as the cerebral cortex, makes up about 40% of the brain and plays a key role in controlling movement, memory, and emotions.
The authors also noted the naturally occurring cortical thinning and thickening of white matter that occurs with age. White matter makes up about 60 percent of the brain and helps process information.
Some changes, such as a decrease in grey matter, persist for two years after birth, while others, such as an increase in white matter, are temporary.
Previous studies have also looked at changes in the brain during pregnancy, such as a decrease in grey matter volume and a reduction in brain size.
What these brain changes during pregnancy mean
Of course, this doesn’t apply to all pregnant brains, so more research is needed, but the brain changes observed in this study shouldn’t be taken negatively, says Sanam Hafeez, PhD, a neuropsychologist in New York City and director of Comprehend the Mind.
“These mutations may help the brain adapt to first-time motherhood, prepare women for life with a newborn and help them cope with the stress and cognitive pressures of childbirth,” Dr Hafeez said.
“Although cognitive functions such as memory may be temporarily altered, the underlying neural rewiring processes appear to drive social and emotional changes during this critical period of development,” she added.
Dr Delia McCabe, neuroscientist and author of the blog Lighter, Brighter You!, supports the idea that the brain undergoes fundamental changes during pregnancy, but that this is inevitable: “These changes make intuitive sense, because the brain needs to change in order for the next generation to thrive,” Dr McCabe adds.
Meanwhile, according to nutritional neuroscientist Dr Amy Reichert, the reduction in grey matter and increase in white matter in pregnant women’s brains is associated with improved brain “regulation” and neurological function, particularly social cognition.
“Animal studies have shown that the hippocampus, which plays an important role in memory and spatial thinking, undergoes changes that may support the cognitive demands of infant care,” she says. “Furthermore, functional connectivity between different brain networks is altered, suggesting widespread restructuring to support the transition to motherhood.”
What is the “Mommy Brain” Phenomenon?
Pouring milk in the pantry. Calling the oven the dishwasher. Driving backwards to pick up my daughter from work. These are just a few of the things I’ve done over the years that I attribute to what I call “mom brain” or “pregnancy brain.”
Could the changes in the brain that occur during and after pregnancy explain these vague moments of awareness? The good news, as Dr Hafeez emphasises, is that “rather than evidence of any brain degeneration, research suggests that significant brain adaptations occur during pregnancy and that these adaptations are not harmful and may even be healthy”.
Dr. Reichert agreed, emphasizing that “the brain changes observed in this study are not harmful but rather appear to be adaptive, preparing women for the demands of motherhood.”
What happens to a lost carton of milk? Dr McCabe said some of the forgetfulness could be explained by a “rewiring” of the brain during pregnancy, which allows it to focus on other things, such as parenting.
Dr Reichert acknowledges that while moments of “mommy brain” are very common, research shows that the brain fog people experience during pregnancy and after giving birth is not the result of “injury” to the brain.
Instead, she says, “These cognitive changes are often temporary and may be more closely related to changing hormone levels, lack of sleep, and the new responsibilities that come with caring for a newborn.”
Brain changes and the postnatal period
In addition to the cognitive changes that occur during pregnancy, there are also hormonal and emotional changes — and for many people, postpartum depression or anxiety begins after giving birth, which Dr Hafeez told Parents magazine could be explained by what’s going on in the brain.
“One group of brain regions that seem to be important are areas involved in emotion regulation, stress responses and social cognition,” she says.
“Brain remodeling changes during pregnancy affect the amygdala, hippocampus and prefrontal cortex, areas involved in emotional processing and stress response,” explains Dr. Hafeez. “Hormonal changes that come with pregnancy, particularly changes in estrogen, progesterone and oxytocin, may also affect these areas, altering mood regulation.”
So what does that actually mean?
“When hormones are involved in changes in the brain, such as in pregnancy, it’s likely that those changes will be accompanied by anxiety or depression because hormones and neurotransmitters work in tandem,” Dr McCabe said.
But there’s a lot more to consider when it comes to possible postpartum mental illness.
“It’s important to remember that postpartum depression and anxiety are complex conditions that are influenced by many factors other than brain structure, including hormonal changes, personal history, genetic risk factors, social support, and environmental stressors,” says Dr. Reichert.
How to look after your brain during pregnancy
Overall, as these experts point out, the changes that occur in the brain during and after pregnancy should be considered beneficial and necessary.
But there’s also a lot you can do to look after your brain during pregnancy.
- Eat a balanced diet: To support healthy brain function, make sure you eat foods rich in omega-3 fatty acids, vitamins, and minerals.
- Take a prenatal vitamin : Make sure your vitamin contains folic acid.
- Stay physically active: Always choose safe activities like walking, swimming or prenatal yoga to reduce stress and promote healthy blood flow to the brain.
- Keep your brain active: Reading, solving puzzles, learning a new instrument or language are all ways to support brain health.
- Stress management: This can be done through mindfulness and meditation.
- Avoid harmful substances: Contains alcohol.
Finally, don’t forget to get plenty of rest and relaxation, which is very important during pregnancy. Dr. Hafeez also recommends that pregnant women get enough sleep to optimize their memory, emotional regulation, and overall cognitive function.
