Searching for the right word in a conversation with a friend or finding your keys in the fridge but having no recollection of putting them there. These might be familiar to you if you’ve been pregnant and experienced so-called ‘baby brain’ or pregnancy brain.
While pregnancy can be a stressful and anxious time for some women, there’s also evidence that it can affect the way your brain functions too. In fact, research published in American Journal of Neuroradiology in 2002 found that women’s brain volume decreased by around 4% during pregnancy.
However, there is a lot we don’t know about why these cognitive changes occur in pregnancy and affect some women more than others. Dr Jonny Kohl, who is studying how bodily states influence brain structure and function at the Frances Crick Institute in London, says: “While numerous anecdotes support the existence of ‘baby brain’, the scientific research behind its causes remains limited. The more challenging aspects, such as forgetfulness and mental fog, are likely linked to a combination of sleep deprivation and hormonal changes. Some of these changes may be adaptive, enhancing responsiveness to babies or helping women avoid harmful substances by altering their senses of smell and taste.”
Baby brain has also become a familiar stereotype of pregnancy, depicting mothers-to-be as caring and warm but also less sharp than usual and excessively hormonal. We’re going to delve into what exactly baby brain is, what causes it and give some tips for coping with it.
What is baby brain in pregnancy?
Baby brain is when women find that they are more forgetful than usual or feel like they can’t think clearly during pregnancy. While a lot of research has been done into other physiological changes women go through in the nine months of pregnancy, less is known about the impact on the brain. GP Dr Deepali Misra-Sharp explains: “‘Baby brain’ refers to cognitive changes, often characterised by forgetfulness, mental fog, and reduced focus, experienced during pregnancy. It is also known as ‘pregnancy brain’ or ‘momnesia’."
Dr Misra-Sharp says there are a few common symptoms women might experience:
- Forgetfulness such as misplacing items or forgetting appointments
- Difficulty concentrating
- Confusion or feeling mentally ‘foggy
- Trouble multi-tasking or processing complex information
But she emphasises that baby brain is not the same as normal forgetfulness. “Normal forgetfulness can happen to anyone, but baby brain is more pronounced and often happens in the context of pregnancy-related changes,” she says.
“It tends to be more pervasive, impacting day-to-day activities and tasks more significantly.”
What causes baby brain in pregnancy?
Baby brain can begin as soon as the first trimester, which is when your progesterone and oestrogen levels are raised, and may become worse during the third trimester. As we said above, more research is needed but nevertheless Dr Kohl says it has “become clear that the brain undergoes profound structural and functional changes during pregnancy, some of which seem to be long-lasting”.
He says studies have found that specific brain regions - most notably the cortex - shrink during pregnancy. “This sounds scary, but it is important to keep in mind that we don't actually know what the underlying microscopic changes are in the brain. Very likely, for instance, this does not mean that nerve cells are being lost - it is much more likely that this is due to structural refinements of specific brain networks,” he explains.
Dr Kohl says the evidence shows that these brain adaptations can make a woman more responsive to their baby. “What is becoming clear is that pregnancy - and the peripartum period - are 'critical periods' during which important neural adaptations are made.”.
But as well as these brain structure changes, baby brain can also be caused by other factors such as hormonal changes, lack of sleep or higher levels of stress which all occur during pregnancy too.
Hormones
Research has shown that changes in hormone levels can affect your cognitive function, in particular your memory and attention span. This study from 2018 found that the hippocampus, the part of your brain related to memory, can be especially sensitive to changes in your hormones.
There is also evidence from studies that pregnancy can change the brain shape and make-up. In 2016 researchers from the Netherlands and Spain used MRI scans to look at how the brain changes. When comparing the brain before the women became pregnant and after they gave birth, they found that their brains’ gray matter - the tissue containing the cell boies and synapses of nerve celles - had shrunk. This loss of volume lasted for at least two years after the birth of their baby. However, rather than this being seen as a negative impact of pregnancy, this study, and another from 2021 concluded that brain plasticity continues through a woman’s life and is part of an adaptive process to prepare for nurturing and responding to the needs of your baby, as also stated by Dr Kohl above.
Sleep
Anyone who has ever struggled with sleep deprivation will know that it can affect your ability to carry out tasks the next day and can make you feel mentally foggy. Pregnancy not only makes you feel more tired than you’ve felt before, but can also stop you sleeping too. While you might not be able to keep your eyes open during the day, the opposite may be the case at night. This is due to hormonal changes and also the growing weight of your baby which can make getting comfortable in bed tricky.
This sleeplessness can affect your memory and ability to carry out tasks which can be frustrating. A lot of women also complain of ‘baby brain’ after their baby has been born when they are still sleep deprived due to night feeds and baby wake-ups. This is completely normal and should ease when a better sleeping pattern is established and your hormones have settled down.
Stress and anxiety can cause problems with your memory, concentration and ability to problem solve. Pregnancy can be a stressful time for some people. It is a huge life change which will impact everything from your career and relationship to your finances and body. Worries or stress around these issues can impact both your day-to-day life and your sleep. This will in turn affect your brain function which may lead to you feeling like you have baby brain.
Talk to your partner and friends and family about your concerns and if you’re feeling especially anxious it’s best to speak to your GP or midwife who will be able to advise you on how to ease this anxiety.
There are a number of vitamins which can help with your brain health and cognitive function so it might be worth checking you’re getting the right amount of these during your pregnancy. Studies have shown that low levels of vitamin D can lead to poor concentration and memory problems. It’s recommended that adults and children living in the UK take a vitamin D supplement from September to March when our bodies can’t make enough from sunlight alone.
Omega- 3 fatty acids are also thought to help with your brain health and for keeping brain fog at bay. DHA supplements, plus eating oily fish such as salmon, mackerel, trout and sardines will help you reach the 200 micrograms a day recommended by nutritionists.
Stress
Stress and anxiety can cause problems with your memory, concentration and ability to problem solve. Pregnancy can be a stressful time for some people. It is a huge life change which will impact everything from your career and relationship to your finances and body. Worries or stress around these issues can impact both your day-to-day life and your sleep. This will in turn affect your brain function which may lead to you feeling like you have baby brain.
Talk to your partner and friends and family about your concerns and if you’re feeling especially anxious it’s best to speak to your GP or midwife who will be able to advise you on how to ease this anxiety.
Vitamins and diet
There are a number of vitamins which can help with your brain health and cognitive function so it might be worth checking you’re getting the right amount of these during your pregnancy. Studies have shown that low levels of vitamin D can lead to poor concentration and memory problems. It’s recommended that adults and children living in the UK take a vitamin D supplement from September to March when our bodies can’t make enough from sunlight alone.
Omega- 3 fatty acids are also thought to help with your brain health and for keeping brain fog at bay. DHA supplements, plus eating oily fish such as salmon, mackerel, trout and sardines will help you reach the 200 micrograms a day recommended by nutritionists
Low levels of vitamin B can also have an impact on memory, concentration and attention, according to researchers. A pregnancy supplement containing vitamin B, including B6 and B12, will be able to help with this.
Low levels of vitamin B can also have an impact on memory, concentration and attention, according to researchers. A pregnancy supplement containing vitamin B, including B6 and B12, will be able to help with this.
7 tips for coping with baby brain in pregnancy
The first thing to remember is that baby brain is very common and normal in pregnancy so try not to make it another thing to get stressed about. There’s a lot you can do to ease any anxiety and alleviate some of the symptoms, but you should also feel reassured that things will return to normal after your baby is born.
- 1) Maintain a balanced diet and stay hydrated - Eating well will help keep your energy levels up which will prevent tiredness and brain fatigue. Make sure you’re getting all of the vitamins and minerals you need during pregnancy, such as those we mentioned above, and stay hydrated. This 2019 study found that dehydration can affect short-term memory and attention span.
- 2) Exercise regularly to help with sleep and stress - Exercising regularly will help you stay healthy during your pregnancy and lead to better sleep. Pregnancy yoga and Pilates will keep you relaxed which will also have a positive impact on your mental health, brain function and sleep.
- 3) Get regular sleep - As we’ve said above, poor quality, or not enough, sleep can leave you feeling sluggish and affect your brain function, whether you’re pregnant or not. But during preganncy sleep is even more important for ensuring your baby grows healthily and you stay healthy too. Try to have a regular bedtime and to switch off devices or other screens which might affect your sleep quality. This 2010 study also found that sleep deprivation can also lead to longer labour, pre-term delivery and higher caesarean rates.
- 4) Write things down - Many people find that writing things down or making lists can help reduce their stress levels and help with forgetfulness. Stick the dates for your antenatal appointments somewhere where you can see them often and set reminders in your phone. Take notes at your appointments, or ask your partner to do it, so you can both remember what the midwife or doctor said.
- 5) Make time for you - It can be easy to feel like you want to squeeze everything in before your baby arrives; from holidays and trips, to seeing friends or family. But doing too much can be exhausting and this will have an impact on your baby brain. Say no to some things and make sure you allocate some dedicated sofa time, or nap time, so you can preserve your energy and reduce any stress you’re feeling about social engagements. Try meditation or massage to keep you physically and mentally relaxed.
- 6) Try activities to aid your brain function - Puzzles like Wordle, crosswords or Sudoku can help keep your brain sharp by strengthening the connections between brain cells, improving your mental speed and memory. Just like you would with physical exercise, try to make time during your week to do some mental exercises too.
- 7) Ask for help - You’re growing a baby which can have a huge physical and mental toll on your body. Delegate some jobs to your partner so you can focus on resting and staying healthy. Tell them that you’re struggling to remember things or that you’re feeling overwhelmed so they can ease some of your worries.
How long does ‘baby brain’ last?
Dr Kohl says many of the brain changes “are driven by hormones such as estradiol (oestrogen) and progesterone, which increase dramatically during pregnancy” which also means that once your hormones have settled down again, your baby brain symptoms should ease.
Dr Misra-Sharp says baby brain can continue after childbirth. “Some women report these symptoms improving a few weeks postnatally, while others may experience lingering effects as they adjust to new motherhood,” she explains.
In the postpartum stage, the cause might be related to sleep deprivation and also your hormone levels if you’re breastfeeding. Your body needs time to recover from pregnancy and childbirth in the fourth trimester, and this will include your brain.
The same tips we listed above for pregnancy can be applied in the postpartum period too. Make sure you’re getting enough sleep, plenty of fresh air and ask for help where you can.
Common myths about brain fog during pregnancy
As we’ve explained above, there are a few probable causes of baby brain but more research is definitely needed in this area. Dr Kohl and his team have carried out research on female mice during pregnancy which showed long-term changs to their brains. He says he “wouldn't be surprised if similar changes occur in the human brain during pregnancy”.
“However, parenting in humans is considerably more complex, and much more shaped by experience and social and environmental factors,” he adds.
One of the main myths about baby brain is that it doesn’t exist, but we think we’ve shown in this article that it does.
Mums share their stories
If you’ve been pregnant, or spoken to friends who’ve had babies, we’re sure you’ve heard stories about moments when baby brain has struck. The mums we spoke to were affected both during their pregnancies and after.
Alice, 39, recalls: “Baby brain + undiagnosed ADHD was hell on earth during my pregnancy. I showed up to work on days I wasn’t working and would just pretend I was popping in to get something once I realised my mistake. I did it so often I just had to accept I’d lost the capacity to understand a calendar.”
Jenny, 36, says: “My brain fog continued in the weeks after my baby was born. One example is when I booked an appointment to get my first haircut in months. I’d enlisted my brother to help by walking the baby around the park while I dashed in for my trim. I fed and fed and fed the baby and handed him over to my brother and walked into the salon stressed and worried. I told them I was ready for my appointment and what it had taken for me to get there on time. It turned out I was there a week early. I felt so stupid and so upset with myself. I would never have made that kind of mistake pre-baby.”
Lindsay, 42, says she used the nappy cream Bepanthen instead of toothpaste after she had her daughter. She said baby brain made her feel “trapped in a head she didn’t want and like she had a permanent hangover”.
Primary school teacher Helen, who has two young children, says she could never remember the right words for things in pregnancy and would feel really frustrated. She said it impacted her self confidence and made her feel like she wasn’t reaching her full potential. She says she was annoyed when it happened again in her second pregnancy but she felt comforted by the fact that she knew it would ease afterwards.
While all of these women felt frustrated with the brain fog and forgetfulness, they had friends and family who reassured them that it was totally normal - and sometimes something to have a giggle over. Stay patient and remember that, while pregnancy can be challeging for some people, it also means you’re going to become a parent which is a wonderful thing.
But we know it can be upsetting if you’re struggling to focus at work or on other tasks because your brain doesn’t feel as sharp as normal. However, Kate who’s 29, says telling her boss what was happening made it feel less stressful and embarrassing. She also bought a paper diary for her desk so she could write down all of her meetings to make sure she wouldn’t forget them.
Brian fog can also have an impact on your mental health and self-esteem. Speak to your midwife or GP if it’s affecting your mood or you’re struggling to complete normal day-to-day tasks.
Johannes (Jonny) Kohl is a group leader at the Francis Crick Institute in London, UK, where he heads the State-dependent Neural Processing Laboratory. After completing his studies in Biochemistry and Neurosciences in Germany, he pursued a PhD in Greg Jefferis' group at the MRC Laboratory of Molecular Biology in Cambridge, UK, focusing on pheromone processing in Drosophila. Following his PhD, he conducted postdoctoral research at Harvard University, where he deconstructed the neural circuits underlying parental behavior in male and female mice. His work earned him the prestigious 2018 Eppendorf & Science Prize for Neurobiology. In 2019, he established his own research group, which explores how bodily states influence brain structure and function.
Dr Deepali Misra-Sharp is an experienced General Practitioner with over a decade in NHS practice and also serves as the clinical lead for Women’s health at her NHS practice based in Birmingham . After graduating from the University of Nottingham’s Graduate Medicine Program in 2010, she completed specialist training in Glasgow and earned Fellowship of the Royal College of General Practitioners (FRCGP) for her contributions to General Practice and Women’s Health.
