Yes, Pregnancy Brain Is Real. And It Starts Sooner Than You Might Think

There's a lot that changes in the body during pregnancy — your nose can change shape, your hips can permanently expand, and the fetus might (temporarily) steal calcium from your bones.

But pregnancy can also affect your brain, both how you process information and your memory. It's called "pregnancy brain" or "baby brain," but it mimics the symptoms of brain fog, which includes forgetfulness, difficulty thinking, feeling cloudy, or struggling to find the right words during a conversation.

"Sometimes called baby brain or momnesia, pregnancy brain is a common form of forgetfulness that begins during pregnancy. Most experts attribute this to the rush of hormones you get in pregnancy, which can be up to six times higher than your prepregnancy levels. These hormones increase shortly after a woman becomes pregnant and greatly increase in the second and third trimesters," says Maeva Althaus, childbirth educator and doula at HypnoDoula Maeva.

Ahead, we're asking experts all about pregnancy brain, including when pregnancy brain starts, what causes it, and if it's treatable.

Is Pregnancy Brain Real?

Though some people contest the validity of pregnancy brain, most experts agree it's a real phenomena.

"The majority of women report some form of pregnancy brain in pregnancy or postpartum. In addition, some studies have found women do have decreased memory and scores on cognitive and executive function tests, suggesting it is a true phenomenon," says Lisa Becht, MD, FACOG and Board Certified Reproductive Endocrinologist at HRC Fertility.

A 2021 report published in Scientific Reports studied 40 pregnant and nonpregnant women and found memory impairment in pregnant women — and "furthermore language skills, particularly naming, were also impaired," according to the researchers. A small study, but a study nonetheless.

Symptoms of baby brain can vary depending on the person and may ebb and flow during pregnancy, but can include absentmindedness, forgetfulness, difficulty focusing, and difficulty multitasking. For the most part, Dr. Becht says, pregnancy brain is the same exact thing as brain fog, but is particular to pregnancy.

When Does Pregnancy Brain Start?

While everyone's experience with pregnancy is different, Althaus says that in her years of doula work, most of her clients have experienced some form of pregnancy brain, and it can start earlier than you might think.

"Pregnancy brain starts with a rush of hormones shortly after a woman conceives, which becomes more significant in the second and third trimesters. Many women experience particularly noticeable pregnancy brain in the third trimester," she says.

What Causes Pregnancy Brain?

Like most changes during pregnancy, baby brain fog is also related to hormones."The high and fluctuating hormone state of pregnancy and postpartum can affect the brain and cause physiologic changes that lead to pregnancy brain," says Dr. Becht. Additionally, stress, changing in sleeping habits, and other physical changes during pregnancy can impact the intensity of symptoms, she says.

While it sounds like a pain, it's thought that pregnancy brain is actually your body's way of focusing on the needs of a future child, and letting the rest fall to the background. "There has been research relegated to looking specifically and directly at cognitive [function] — as well as actual structural brain changes via MRI — in pregnant women," says Kecia Gaither, MD, a double board-certified in ob-gyn and Maternal Fetal Medicine and Director of Perinatal Services/Maternal Fetal Medicine at NYC Health. "Gray matter apparently decreases in those areas of the brain relegated to processing and responding to social signals. These changes are proposed to allow moms to respond better solely to their infants needs."

How Long Does Pregnancy Brain Fog Last?

For most people, pregnancy will last into postpartum, with different people feeling back to normal on their own individual timetable.

A 2016 study published in Nature Neuroscience suggests that pregnancy can have a long-lasting impact on brain structure, though it's unclear exactly how those findings may impact the duration of pregnancy brain.

Of course, right after the baby comes, you'll likely be somewhat sleep deprived, and it can be difficult to discern what's pregnancy brain and what's fatigue.

The takeaway? You'll need to give yourself some time and patience as your body acclimates to so many changes.

Can You Treat Pregnancy Brain Fog?

While there's no cure, a consistent sleep schedule is key in managing the effects of pregnancy brain says Dr. Becht. Likewise, exercise and good nutrition may help with symptoms.

Pregnancy and adjusting to postpartum life may not always be easy, but if you're struggling with the inability to concentrate or feeling muddled, reach out to your doctor for support and guidance.