Placenta Brain: the cognitive burden of pregnancy?Placenta Brain: the cognitive burden of pregnancy?
All In The Mind
Ever had a case of 'placenta brain', or 'pregnancy stupidity'? Can carrying a foetus make you drop your cognitive bundle? Expecting women worldwide find themselves suddenly forgetful and absent minded. So why is there so little research into the phenomenon? Are hormones to blame, or the psychological burden of approaching mumhood? Does it have an evolutionary function? Libbi Gorr and others contemplate the hungry placenta..
30:04•21 Oct 2006
Placenta Brain: Forgetfulness, Hormones and the Myths of Pregnancy
Episode Overview
- Pregnant women often report forgetfulness and confusion, but laboratory tests usually show only very slight or no cognitive differences compared with non-pregnant women.
- Professor Neil Watson’s research hints that carrying a girl may be linked to greater working memory changes than carrying a boy, possibly via hormones like hCG affecting the hippocampus.
- Dr Ros Crawley suggests that pregnancy brain may be amplified by social stereotypes, with pregnant women experiencing common lapses that others also have but are judged differently.
- Real-life stories from women show how pregnancy can feel mentally chaotic, yet these experiences sit alongside strong emotional connections to the unborn baby.
- Marianne Stark’s study indicates that spending regular time in nature can reduce undetected cognitive errors, offering a simple way to ease mental fatigue during late pregnancy.
“Yes, a placenta is subversive… I'm putting in a central nervous system all by myself without even thinking.”
What emotional and surprising tales of pregnancy brain are out there? This episode of All In The Mind shines a light on so‑called "placenta brain"—those forgetful, foggy moments many pregnant women swear they experience—and asks whether the science backs up the jokes. Host Natasha Mitchell and producer Abby Thomas bring together researchers and mums-to-be to sort myth from measurable change. Assistant Professor Marianne Stark and cognitive psychologist Dr Ros Crawley talk through studies on memory, attention and driving during pregnancy.
Crawley, for instance, tested women on 13 different cognitive tasks and found, as she puts it, "for the majority of them there was no difference at all between the pregnant women and the non-pregnant women", hinting that social stereotypes may be doing a lot of the heavy lifting. Neuroscientist Professor Neil Watson adds a different angle, looking at the hormonal storm created by the placenta.
His work suggests that fetal sex might influence working memory, with women carrying girls showing more slowing than those carrying boys. He points to human chorionic gonadotropin (hCG)—the hormone picked up in pregnancy tests—as a possible player, noting its effects on the hippocampus, a brain area key for forming new memories.
Balancing the lab talk are real-life stories from women like Samantha and performer Libby Gore, whose hilarious mishaps range from leaving a car running in the street to spraying hairspray instead of deodorant. Libby’s cheeky line that "a placenta is subversive" captures both the frustration and odd pride that can come with feeling mentally scrambled while building a baby.
Stark also shares research suggesting that time in nature may help ease mental fatigue, with pregnant women making fewer undetected errors after regular doses of outdoor "fascination". If you’ve ever blamed pregnancy for losing your keys—or worried you’d never get "your brain" back—this conversation might make you smile, think, and ask: how much of placenta brain is biology, and how much is society’s expectations?
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