Pregnancy Brain: Myth or Reality?

Relax, pregnancy does not change your brain. But it may affect how mentally sharp you feel.

Medically Reviewed by Traci C. Johnson, MD on September 03, 2014
3 min read

You may have heard about little bouts of forgetfulness during pregnancy. It's sometimes called momnesia or sometimes "pregnancy brain." At least one Australian studyhas cast doubt on whether there is such a thing as pregnancy brain.

But what if it's real? What can you do about it while you're pregnant?

Pregnancy does not change a woman's brain even though some women don't feel as sharp as usual when they're pregnant.

Helen Christensen, PhD, of The Australian National University, says, "If you read pregnancy manuals and listen to pregnant mothers -- yes, there is such a thing as pregnancy brain or momnesia. And there is also evidence from research showing deficits in memory."

But, she adds, "the evidence from our study shows that the capacity of the brain is unaltered in pregnancy."

It’s 100% normal to have memory lapses or be forgetful when you’re busy, stressed, or short on sleep, Christenson says.

Jane Martin, MD, director of the Neuropsychological Testing and Evaluation Center at New York's Mount Sinai Medical Center, agrees. "When you are not getting enough sleep and are multitasking, nobody's memory is good," she says. "You are not cognitively sharp when you haven't slept well."

Surging hormone levels and new priorities may help explain why pregnancy brain happens.

"There is 15 to 40 times more progesterone and estrogen marinating the brain during pregnancy," Louann Brizendine, MD, director of the Women's Mood and Hormone Clinic at the University of California, San Francisco, says. "And these hormones affect all kinds of neurons in the brain. By the time the woman delivers, there are huge surges of oxytocin that cause the uterus to contract and the body to produce milk -- and they also affect the brain circuits."

Pregnancy also shuffles what gets your attention. Your IQ doesn't change, but your priorities do.

"You only have so many shelves in your brain, so the top three are filled with baby stuff," Brizendine says.

Hormones may also affect spatial memory -- which includes remembering where things are -- in pregnant women and new moms, a British study shows.

Pregnancy brain is "the feeling of walking into a room, going after something, and not remembering what you went for about five to 10 times a day," Brizendine says.

There may also be an evolutionary aspect to it. Women’s health expert Donnica Moore, MD, says, "It has been postulated that, from an evolutionary standpoint, this memory impairment may be helpful so that women will forget about other stuff and focus on caring for the child."

Many pregnant women and new moms spend a lot of time thinking about the changes that having a baby will bring or taking care of their newborn. As a result, their short-term memory may suffer.

Moore says if you feel you're not as sharp as usual, that should be "your first tip-off that, when you are preparing to have a baby, you need to simplify other areas of your life because life is about to get a lot more complicated."

After the baby arrives, sleep deprivation is clearly a contributing factor. Brizendine says, "Women accumulate up to 700 hours of sleep debt in the first year after having a baby, and that causes the brain not to be at its best for things other than caring for the baby."

So what can you do?

Write things down. Ob-gyn Geeta Sharma, MD, of New York-Presbyterian Hospital/Weill Cornell Medical Center, says, "Most patients comment, 'I have to write my questions down or I will forget,' and then mention that they are more forgetful in general."

Jotting things down, whether on a grocery list or a list of questions to ask your obstetrician, helps. "Make lists, use a day planner, and keep your sense of humor," Moore says.

Get more sleep. This may be tricky for new parents. But it can make a real difference. "Most moms need more deep sleep, and within a week of getting better sleep, some of this momnesia stuff goes away," Brizendine says.

"If your memory problems are getting in the way of taking safety precautions or if you find yourself doing things like forgetting to put your child in the car seat, worry," Brizendine says. "Otherwise, it's normal."