What is “pregnancy brain,” and what can you do about it?

Pregnancy is a singular experience, and there’s no way to predict how you will feel physically, mentally and emotionally in the first weeks after a positive pregnancy test. You may feel more tired than usual, perfectly normal or a little weepy when that one commercial comes on. You may also feel forgetful or have trouble concentrating, and start to wonder if you’re experiencing #PregnancyBrain.

But is pregnancy brain real? Does your brain actually change during pregnancy? And if it does, can you do anything about it? Let’s get into the research.

What is pregnancy brain?

Typically the phrase “pregnancy brain” is used to describe bouts of forgetfulness, memory lapses, brain fog, an inability to concentrate and/or spaciness during pregnancy. Unlike nausea or fatigue, you won’t find pregnancy brain listed as a symptom in your medical chart. However, if you mention it to your ob-gyn, they will likely have a broad understanding of how you’re feeling.

Culturally that feeling of spaciness while pregnant has been embraced in the form of clever phrases and hashtags: “pregnancy brain,” “mom brain,” “baby brain” and “momnesia” are a few favorites. We pushed aside the witty hashtags to make room for science and discovered a few things you should know about when you might experience it, and how long it may last.

When does pregnancy brain start?

Pregnancy brain symptoms can happen at any time during your pregnancy or the postpartum period.¹ If you do experience mental fogginess during pregnancy, it may not start right away. Or you may not experience it at all (lucky you!).

Keep in mind, while pregnancy brain can start early, none of its associated symptoms should be taken as definitive signs of pregnancy. Just because you forgot an appointment yesterday morning or you had trouble multitasking last week doesn’t necessarily mean you’re pregnant. The best way to know for sure is to take a pregnancy test.

How long does pregnancy brain last?

Symptoms such as brain fog, forgetfulness and spaciness may happen once or twice during your pregnancy, or they may last throughout. You may experience brain fog more acutely during times of fatigue or fitful sleep, such as in the early or end stages of your pregnancy. You may also experience these symptoms more frequently near the end of your pregnancy, as stress and anxiety may be on the rise as you physically, mentally and emotionally prepare for the arrival of your little one.

Is pregnancy brain real?

The research on this is mixed — and fascinating — so let’s explore the data and what it could mean for you. But just because the science behind understanding pregnancy brain isn’t 100% definitive, that doesn’t make your experiences or symptoms any less real or valid.

That said, let’s start by understanding more about brain plasticity, and specifically maternal brain plasticity. In scientific sources, the term brain plasticity is broadly used to describe the brain’s ability to change, structurally and functionally, as needed — its flexibility and adaptability. Recent research points to evidence that hormones your body produces during pregnancy and while you’re interacting with your baby after pregnancy may result in some structural and functional changes in your brain.¹ Basically, your brain adapts to help you better bond and empathize with your baby.

Recent research has also shown that pregnancy could lead to reduced gray matter. Several studies have used neuroimaging to look at brain changes (specifically gray matter volume reduction) before conception, during the first months of postpartum and years after giving birth. For example, in a recent 2021 study, reduced gray matter persisted six years later.²

In 2016, “Nature Neuroscience” published a study: “Pregnancy leads to long-lasting changes in human brain structure.”³ Popular media had a field day, with “pregnancy brain” leading headlines around the globe, a phenomenon researched in a “Frontiers in Sociology” 2021 study titled “Mombrain and Sticky DNA.”⁴

Several themes evolved from the 2021 study’s focus groups, including one they named “A Kind of Brain.”⁴ Some of the people in the focus groups said that acknowledging “mom brain” can be a “validating, subjective experience.”⁴ Others said that the idea of “mom brain” can be “stigmatizing,” thinking back to times they felt a need to, for example, overperform at work while pregnant in part because of perception.⁴

What causes pregnancy brain?

Many things can contribute to the symptoms of pregnancy brain, including hormonal shifts, sleep issues and stress. If you’re pregnant and not feeling as sharp as usual, it’s worth exploring if any of these factors may be an issue for you — especially since identifying potential causes can help you adapt and adjust to start feeling better. Let’s take a look.

Do hormones cause pregnancy brain

If you’re feeling forgetful, or not as quick with your thinking, some research does point to hormonal changes as a possible cause. After you ovulate, your egg will travel through the fallopian tube where it may be fertilized by a sperm. A fertilized egg then travels down the tube into the uterus in order to attach itself to your uterine lining. Once it implants, it begins producing increasing amounts of hCG (human Chorionic Gonadotropin) hormone, which keeps your estrogen and progesterone levels high. Around week 10, hCG levels plateau, after which time they slowly decline.

Studies have shown that hormonal changes affect cognitive function.⁵ Some studies of pregnant women have shown that fluctuations of progesterone and estrogen can affect memory and attention.⁵ The hippocampus, the part of your brain primarily related to memory, is particularly sensitive to changes in sexual reproductive hormones.⁵

This brings us back to brain plasticity. A study in the “Journal of Neuroendocrinology” indicates that hippocampal plasticity (or the degree to which the structure of the hippocampus changes) during pregnancy is due to a combination of new experiences and changes in hormones.⁶

A 2021 study of the association of hormones and cognition found reduced gray matter volume in part of the brain involved with learning and motor control (specifically, in the left putamen), during pregnancy.⁷ Pregnant people showed reduced processing speed and cognitive flexibility, but the study also suggested that the potential cause — hormonal transition phases actively reshaping the brain — ultimately had a positive outcome: helping the parent-to-be adapt to a new role.⁷

Do sleep disruptions cause pregnancy brain?

Sleep disruptions during pregnancy, whether you find yourself having trouble falling asleep or you’re dozing off midway through the day, may contribute to that feeling of fogginess. And sleep problems are common in the first trimester. In a 2020 study, 1,338 participants completed a questionnaire before week 16 of their pregnancy. Sleep problems included “taking a long time to fall asleep” (23%), “waking up too early (47%) and “lying awake most of the night” (14%).⁸ In a 2020 study of more than 7,000 pregnant participants, “daytime drowsiness” (86.35%) and “naps impeding daytime function” (27.18%) were reported in the first trimester.⁹

If your sleep is disrupted, you’re sleeping for shorter periods than usual and even if you’re sleeping more than usual, your cognition may be affected. A 2019 journal article in “SLEEP” discussed the “Goldilocks” amount of sleep, suggesting that both too little and too much sleep may negatively affect cognition.¹⁰ Instead of thinking about sleep in a linear fashion (where less sleep than average leads to poorer cognition, and more leads to better outcomes), the article suggests thinking of it as U-shaped, with shifts toward both shorter and longer sleep habits linked to poorer reasoning and verbal abilities.¹⁰

Do stress and anxiety cause pregnancy brain?

Stress and anxiety can impact memory, problem-solving and work performance. According to The American College of Obstetricians and Gynecologists (ACOG), anxiety affects nearly one in five adults, including those who are pregnant.¹¹ Anxiety in particular can come with a handful of mental, emotional and physical symptoms outside of pregnancy brain, too. These can include sleep issues, rapid heartbeat, dizziness, headaches, nausea, chest or stomach pains, worrying about things more than you normally do, tension, avoidance or a sense of doom.¹¹ It’s normal to feel some stress and anxiety, especially when newly pregnant. However, if you’re experiencing any of these symptoms, it’s important to talk to a healthcare professional. Managing your anxiety benefits both you and your baby, and according to ACOG, with treatment you are less likely to have severe postpartum depression.

While major life changes do impact anxiety and stress, a 2019 study looked at the relationship between everyday anxiety and stress with working memory performance in nonclinical populations. It suggests that while working memory holds up pretty well against normal, everyday variances, short-term anxiety may disrupt cognitive processes.¹²

So what can you do about pregnancy brain?

Now we know some of the causes, but what can you do about pregnancy brain if you’re experiencing it already? Or maybe you’re just a planner and want some go-to solutions in case you start feeling a little “out of it” later in your pregnancy. Either way, these ideas may help you feel a little less foggy.

1. Write things down. Rely on a shared online calendar versus your memory. Make lists, including daily to-do lists. Take notes during your first prenatal visit and even when you might not normally do so, such as when you’re having a quick 1:1 with a colleague.
2. Simplify your life. Don’t be shy about saying no. If you’re tired, skip that late-night function. If your schedule is stressing you out, look for opportunities to RSVP “Thanks, but no thanks.”
3. Engage in physical activity. Exercise while pregnant or trying to conceive has many benefits, including how well and how long you sleep.⁸ That positive effect on your sleep, in turn, has a positive effect on your mental state.⁸
4. Ask for help. Do you keep forgetting to schedule the dog’s vet appointment? Ask your partner to do it. Does the idea of doing taxes this year hurt your brain? Consider hiring someone. You have so much to think about right now — there’s no need to feel guilty about freeing up some brain space.
5. Find camaraderie. Ask family members or friends if they’ve experienced similar issues while pregnant. You can also post the question in online groups. Knowing that others have struggled with cognition issues as well, and learning how they worked through them, can bring peace during times of frustration and anxiety.

Your mind and body will go through so many changes during pregnancy. You are, literally, growing a human inside of you — so cut yourself some slack! How you choose to think about these changes is completely up to you, whether you enjoy hashtagging it up while posting about #PregnancyBrain online or prefer to keep the conversation between you and your immediate support system. Maybe you’ll never even experience it yourself, but now that you know more about it you could be there for a pregnant friend who needs support! How you manage, feel and talk about pregnancy brain is up to you — and you are always free to change your mind.

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