Neuroscientist Liz Chrastil got the unique chance to see how her brain changed while she was pregnant and share what she learned in a new study that offers the first detailed map of a woman’s brain throughout gestation.
The transition to motherhood, researchers discovered, affects nearly every part of the brain.
Although the study looks at only one person, it kicks off a large, international research project that aims to scan the brains of hundreds of women and could one day provide clues about disorders like postpartum depression.
“It’s been a very long journey,” said Chrastil, co-author of the paper published Monday in Nature Neuroscience. “We did 26 scans before, during and after pregnancy” and found “some really remarkable things.”
More than 80 percent of the regions studied had reductions in the volume of gray matter, where thinking takes place. This is an average of about 4 percent of the brain — nearly identical to a reduction that happens during puberty. While less gray matter may sound bad, researchers said it probably isn’t; it likely reflects the fine-tuning of networks of interconnected nerve cells called “neural circuits” to prepare for a new phase of life.
The team began following Chrastil — who works at the University of California, Irvine, and was 38 years old at the time — shortly before she became pregnant through in vitro fertilization.
During the pregnancy and for two years after she gave birth, they continued doing MRI brain scans and drawing blood to observe how her brain changed as sex hormones like estrogen ebbed and flowed. Some of the changes continued past pregnancy.
“Previous studies had taken snapshots of the brain before and after pregnancy, but we’ve never witnessed the brain in the midst of this metamorphosis,” said co-author Emily Jacobs of the University of California, Santa Barbara.
Unlike past studies, this one focused on many inner regions of the brain as well as the cerebral cortex, the outermost layer, said Joseph Lonstein, a professor of neuroscience and psychology at Michigan State University who was not involved in the research. It’s “a good first step to understanding much more about whole-brain changes that could be possible in a woman across pregnancy and postpartum,” he said.
Research in animals has linked some brain changes with qualities that could be helpful when caring for an infant. While the new study doesn’t address what the changes mean in terms of human behavior, Lonstein pointed out that it describes changes in brain areas involved in social cognition, or how people interact with others and understand their thoughts and feelings, for example.
The researchers have partners in Spain and are moving forward with the larger Maternal Brain Project, which is supported by the Ann S. Bowers Women’s Brain Health Initiative and the Chan Zuckerberg Initiative.
Eventually, they hope scientists can use data from a large number of women for things like predicting postpartum depression before it happens.
“There is so much about the neurobiology of pregnancy that we don’t understand yet, and it’s not because women are too complicated. It’s not because pregnancy is some Gordian knot,” Jacobs said. “It’s a byproduct of the fact that biomedical sciences have historically ignored women’s health.”

WELLINGTON: It’s noisy, smelly, shy — and New Zealand’s bird of the year.
The hoiho, or yellow-eyed penguin, won the country’s fiercely fought avian election on Monday, offering hope to supporters of the endangered bird that recognition from its victory might prompt a revival of the species.
It followed a campaign for the annual Bird of the Year vote that was absent the foreign interference scandals and cheating controversies of past polls. Instead, campaigners in the long-running contest sought votes in the usual ways — launching meme wars, seeking celebrity endorsements and even getting tattoos to prove their loyalty.
More than 50,000 people voted in the poll, 300,000 fewer than last year, when British late night host John Oliver drove a humorous campaign for the pūteketeke — a “deeply weird bird” which eats and vomits its own feathers – securing a landslide win.
This year, the number of votes cast represented 10 percent of the population of New Zealand — a country where nature is never far away and where a love of native birds is instilled in citizens from childhood.
“Birds are our heart and soul,” said Emma Rawson, who campaigned for the fourth-placed ruru, a small brown owl with a melancholic call. New Zealand’s only native mammals are bats and marine species, putting the spotlight on its birds, which are beloved — and often rare.
This year’s victor, the hoiho — its name means “noise shouter” in the Māori language — is a shy bird thought to be the world’s rarest penguin. Only found on New Zealand’s South and Chatham islands — and on subantarctic islands south of the country — numbers have dropped perilously by 78 percent in the past 15 years.
“This spotlight couldn’t have come at a better time. This iconic penguin is disappearing from mainland Aotearoa before our eyes,” Nicola Toki, chief executive of Forest & Bird — the organization that runs the poll — said in a press release, using the Māori name for New Zealand. Despite intensive conservation efforts on land, she said, the birds drown in nets and sea and can’t find enough food.
“The campaign has raised awareness, but what we really hope is that it brings tangible support,” said Charlie Buchan, campaign manager for the hoiho. But while the bird is struggling, it attracted a star billing in the poll: celebrity endorsements flew in from English zoologist Jane Goodall, host of the Amazing Race Phil Keoghan, and two former New Zealand prime ministers.
Aspiring bird campaign managers — this year ranging from power companies to high school students — submit applications to Forest & Bird for the posts. The hoiho bid was run by a collective of wildlife groups, a museum, a brewery and a rugby team in the city of Dunedin, where the bird is found on mainland New Zealand, making it the highest-powered campaign of the 2024 vote.
“I do feel like we were the scrappy underdog,” said Emily Bull, a spokesperson for the runner-up campaign, for the karure — a small, “goth” black robin only found on New Zealand’s Chatham Island.
The karure’s bid was directed by the students’ association at Victoria University of Wellington, prompting a fierce skirmish on the college campus when the student magazine staged an opposing campaign for the kororā, or little blue penguin.
The rivalry provoked a meme war and students in bird costumes. Several people got tattoos. When the magazine’s campaign secured endorsements of the city council and local zoo, Bull despaired for the black robin’s bid.
But the karure — which has performed a real-life comeback since the 1980s, with conservation efforts increasing the species from five birds to 250 — took second place overall.
This weekend as Rawson wrapped up her campaign for the ruru, she took her efforts directly to the people, courting votes at a local dog park. The veteran campaign manager who has directed the bids for other birds in past years was rewarded by the ruru placing fourth in the poll, her best ever result.
“I have not been in human political campaigning before,” said Rawson, who is drawn to the competition because of the funds and awareness it generates. The campaign struck a more sedate tone this year, she added.
“There’s been no international interference, even though that was actually a lot of fun,” she said, referring to Oliver’s high-profile campaign.
It was not the only controversy the election has seen. While anyone in the world can vote, Forest & Bird now requires electors to verify their ballots after foreign interference plagued the contest before. In 2018, Australian pranksters cast hundreds of fraudulent votes in favor of the shag.
The following year, Forest & Bird was forced to clarify that a flurry of votes from Russia appeared to be from legitimate bird-lovers.
While campaigns are fiercely competitive, managers described tactics more akin to pro wrestling — in which fights are scripted — than divisive political contests.
“Sometimes people want to make posts that are kind of like beefy with you and they’ll always message you and be like, hey, is it okay if I post this?” Bull said. “There is a really sweet community. It’s really wholesome.”