Have you ever walked into a room and forgotten why you went there? Or misplaced your keys for the third time in a week? If you're pregnant, you may have heard someone blame these forgetful moments on "pregnancy brain." But is pregnancy brain a real thing, or just another pregnancy myth?

"Pregnancy brain actually is a real thing," says Nebraska Medicine certified nurse-midwife Alyssa Fischer, APRN-CNM.

According to the American Psychological Association, between 50 and 80% of pregnant women report experiencing memory and thinking changes during this time. But while pregnancy can affect memory and concentration, research suggests these changes may have more to do with how the brain adapts to pregnancy than a decline in thinking ability.

What is pregnancy brain?

Pregnancy brain, sometimes called pregnancy brain fog, describes changes in memory, focus, and concentration during pregnancy.

Common symptoms include:

• Forgetting appointments, tasks, or items on your to-do list
• Misplacing everyday items, like your keys or phone
• Having trouble concentrating
• Feeling mentally foggy or easily distracted
• Finding it harder to remember things when multitasking

“While these changes can be frustrating, they're generally considered a normal part of pregnancy,” says Fischer.

What causes pregnancy brain?

There's no single proven cause of pregnancy brain. Instead, researchers believe several factors may contribute, including:

• Hormonal changes. Shifting estrogen levels may affect how the brain works during pregnancy.
• Sleep deprivation. Poor sleep can make it harder to focus and remember things, especially during the third trimester.
• Fatigue and physical changes. Nausea, poor sleep, and difficulty eating or drinking enough can leave you feeling mentally drained.
• Stress and distractions. Preparing for a baby brings new responsibilities and worries that can compete for your attention.

Interestingly, research also shows that the brain itself changes during pregnancy.

"Some brain MRIs will show a significant decline in gray matter in the brain," Fischer says.

Gray matter is the part of the brain involved in functions such as memory, emotions, and decision-making. However, these changes don't necessarily mean the brain is functioning less effectively. Instead, researchers believe some of these changes may help prepare the brain for motherhood, including strengthening the ability to bond with and respond to a baby.

"Our brains change, they don't decline," Fischer says.

How early does pregnancy brain start?

Pregnancy brain can begin as early as the first trimester. During early pregnancy, rising hormone levels, fatigue, nausea, and poor sleep may all contribute to forgetfulness and difficulty concentrating.

Symptoms may become more noticeable as pregnancy progresses. According to Fischer, pregnancy brain tends to be most significant during the third trimester, when physical discomfort, interrupted sleep, and the anticipation of childbirth can make it harder to focus.

How long does pregnancy brain last?

Pregnancy brain doesn't necessarily disappear once your baby arrives. After delivery, some parents continue to experience forgetfulness and brain fog, often called "mom brain."

Researchers haven't established exactly how long these changes last. Some people notice improvement after giving birth, while others report feeling more mentally sharp after they stop breastfeeding. Hormonal changes, sleep deprivation, and the demands of caring for a newborn may also play a role.

However, Fischer emphasizes that research doesn't show a significant overall decline in thinking ability during or after pregnancy. Rather, the brain may be adapting to new priorities and responsibilities.

What helps with pregnancy brain?

While you may not be able to prevent pregnancy brain entirely, a few simple strategies can make everyday tasks easier.

• Write things down. Keep a notebook or use your phone to record appointments, reminders, and to-do lists.
• Create routines. Take your prenatal vitamin at the same time each day and keep important items, like keys, in a designated place.
• Prioritize sleep. Get as much rest as possible and talk with your provider if you're having trouble sleeping.
• Eat and drink regularly. Adequate nutrition and hydration can help support your energy and concentration.
• Ask for help. Share household tasks and responsibilities when you're feeling overwhelmed.

Fischer also recommends keeping a notebook beside your bed. Writing down thoughts or tasks that pop into your head at night may help you relax instead of worrying you’ll forget them.

When should you talk to your doctor about pregnancy brain?

Although mild forgetfulness is common during pregnancy, don't automatically assume every change in how you feel is pregnancy brain. Iron deficiency, vitamin D deficiency, thyroid problems, sleep disorders, anxiety, and depression can also contribute to fatigue and difficulty concentrating.

Let your health care provider know if you're experiencing brain fog, especially if you also notice:

• Significant dizziness
• Shortness of breath
• Persistent headaches
• Heart palpitations
• Major changes in mood
• Fatigue that makes everyday activities difficult

Symptoms that persist, return frequently, or become more severe should be evaluated by your provider.

The bottom line: Pregnancy brain is a common experience, but it doesn't mean you're becoming less capable. Your brain and body are going through significant changes as you prepare for your baby. If forgetfulness or brain fog is affecting your daily life, your pregnancy care team can help identify possible causes and ways to feel better.