Our Bodies, Our Lives - Pregnancy brain: Is it fact or fiction?

By Drs. Tristi Muir and Catherine Hansen

 

I know I opened my calendar to add something to it … but what was it?” An exhausted and exasperated Julia, who is 7 months pregnant, finds that words escape her, and on occasion, she heads into a room only to forget what she is looking for. Is this “pregnancy brain” — also called momnesia or pregnesia?

 

Women, and men, often joke about the memory lapses caused by pregnancy. But is it true? What are the changes that take place? Are the changes all bad?

 

First of all, we can assure you that there are some very real changes that occur in the brain during pregnancy. Hormone levels of estrogen and progesterone (hormones produced by a woman’s ovaries) increase 30 to 70 fold. The brain is responsive to hormonal changes. But do these hormones alter cognition?

 

Researchers have worked for decades to understand the cognitive and behavioral changes that accompany pregnancy. The results of these studies are mixed — some indicating that changes in verbal memory do occur, but many others do not find cognitive differences between a nonpregnant and pregnant brain.

 

Let’s consider the situation with mice. Which mouse do you think can maneuver a maze faster: the nonpregnant or the pregnant mouse? The pregnant mouse can make it to the other the end of the maze faster that the nonpregnant mouse, because she is on a mission.

 

Her job is not only to protect herself, but protect the “baby mice on board.” Her senses for danger detection are heightened, and she expertly maneuvers to get wherever she is going.

 

Pregnancy triggers many beneficial hormonal changes not only in a mouse brain, but also in a woman’s brain. Women have an improved responsiveness to dangerous situations. They are less rattled by stress, and after their baby is born, their brains are tuned into their baby’s unique cry. With the help of hormones, a woman’s brain is wired to become the protective, calm and nurturing parent her baby needs.

 

While we blame pregnancy for a momentary lapse of memory, sleep deprivation may actually be the cause of forgetfulness. During pregnancy, sleep becomes interrupted. Women have to wake up to roll over or their bladder sends them running to the bathroom. In the first year after the baby’s birth, a woman accumulates up to 700 hours of sleep debt.

 

Without a definitive answer on the effects of pregnancy on cognition, we are left to conclude that if there is a difference, it must be small and insignificant. If you or someone you know is more forgetful while pregnant, we suggest you write things down to prompt memory. We also suggest that women make quality (uninterrupted) sleep a priority in their lives. This will improve the hazy brain feeling of sleep deprivation.

 

Pregnancy is an amazing event that prepares us to be parents. We challenge women to embrace rather than blame “pregnancy brain,” which is, in part, responsible for the preparation needed to embark on the amazing journey of parenthood!

 

Our Bodies, Our Lives focuses on issues surrounding women's sexual, gynecological and emotional health. Drs. Tristi Muir and Catherine Hansen are gynecologists at UTMB.  Visit the website for more information.