Being pregnant

Mommy brain

Think your mind has turned to mush? Not to worry -- it's all in your head

By Teresa Pitman
Mommy brain

Forget to pick up the dry cleaning on your way home from your last prenatal appointment? Have trouble finding the files you needed for a project at work? You can bet someone will mention that you’re getting mommy brain.

“When I was pregnant with my second son, I had some funny mommy brain moments,” says Torontonian Lara Dominguez. “For some reason, my bread maker and I had issues. Every time I went to make a loaf of bread, something went wrong. One time I forgot to put in the blade to mix the ingredients. The next time I put the blade in and forgot to plug in the machine. My last mishap came when I put in the blade, remembered to plug it in and forgot to press start.”

Many women recall similar experiences. Somehow, once you’re pregnant or mothering a new baby, you start forgetting things. Or you have trouble concentrating on that deftly written novel you brought home from the library, even though you breezed through the author’s previous works. Women sometimes say they think their brains have turned to mush.

Diminished mental capacity?

But is it true? Has motherhood really diminished your mental capacity?

Candace Nast says her answer is a resounding no! The Windsor, Ont., woman returned to school full-time as a single mother with three young children, the youngest only a year old, and says: “My mommy brain got me through school with flying colours. I got an A average — top of my class — and won the board of governors’ award. I think it was my mothering experience that helped me develop the organizational skills and kept me focused.”

Who’s right? In her book, The Mommy Brain, Katherine Ellison reviews the research, which turns out to be somewhat contradictory. Some researchers have reported that pregnant women and new mothers had lower scores on tests of cognitive ability, particularly those involving verbal memory. For example, a 2006 study compared 57 pregnant women with 50 non-pregnant women matched for age and education levels. The women in each group were tested on their ability to memorize new words, and the pregnant women had consistently lower scores, right up to 32 weeks postpartum.

Other studies produced different results. A 1989 study followed 33 women from before conception throughout their pregnancies, giving them weekly learning and comprehension tests. The results: “Without exception, performance on the cognitive tests improved during pregnancy.” Even if some of the improvement was due to practice in doing tests, these results certainly don’t support the idea that women’s mental faculties deteriorate during pregnancy.

Motherhood makes you smarter

A 2003 UK study compared pregnant and non-pregnant women on three different types of tests, and followed up with additional testing until a year after the babies were born. While they found no significant difference in performance between the two groups, the pregnant women reported that they had more difficulty in remembering and focusing their attention, even though the objective test results didn’t bear this out. The researchers speculate that this might result from women’s expectations that their thinking will suffer when they’re pregnant.

It’s possible that the differing results may stem from the content of the tests. A 1999 study from Australia found that pregnant women were much better at learning words that related to pregnancy, birth and babies than women who were not pregnant.

Ellison contends that, in fact, motherhood makes women smarter. She points to studies on rats which found that, during pregnancy, mother rats’ brain cells grew many more dendrites and dendrite spines. The same researchers found that after those rats gave birth, they were able to catch the insects they eat three times as fast as rats that don’t have babies.

Sensory enhancement

Donald Buckley, professor of biology at Quinnipiac University in Connecticut, says it’s reasonable to assume a similar process happens in women, and that the proliferation of dendrites makes sense in evolutionary terms. Since caring for babies is so important for the survival of the species, some adaptations would be expected. Sensory enhancement is one example — women find their sense of smell is more acute during pregnancy and postpartum, which helps them avoid foods that might be a bit off or have toxins, and to distinguish their babies from other newborns.

Buckley adds that these additional dendrites set the stage for an intensive period of learning; a similar process takes place in the brains of new babies and teens going through puberty. What happens to these additional dendrites, though, depends on the woman’s learning experiences. “It’s like a block of granite that a sculptor might use to begin a new work of art. As he carves, he’ll remove the pieces of the rock that he doesn’t need. In the same way, dendrites and neurons that aren’t needed are pruned away,” Buckley explains. This process probably explains some of the mommy-brain feelings women have. With your brain focusing on all the new experiences of pregnancy, birth and becoming a mother, the less important neurons involved in running the bread machine, for example, might just get pruned away.

Learning ready

Pregnancy and early motherhood is the perfect environment for a lot of learning, observes Ellison. In her book, she points out that this is a time of many new and often challenging experiences, in a context of positive emotions. Buckley agrees that these are conditions that promote learning and further brain development. He also feels the brain may be especially “learning ready.” There is a development window associated with pregnancy and child care due to the proliferation of neurons and dendrites.

More forgetful?

So if our pregnant and new-mom brains are actually learning better, why do we feel that we’re more forgetful and having trouble concentrating?

Ellison writes that some of this is perception. She cites a study that found when people were shown apparently pregnant and non-pregnant women doing identical work, they rated the pregnant women as less competent. Naturally, pregnant women tend to carry this belief into their own lives.

Buckley adds: “It doesn’t seem likely that radical changes in brain structure and cognitive abilities could start immediately after conception, yet women say they are more forgetful as soon as they are aware of their pregnancies.” He says pregnant and postpartum women feel less “with it” cognitively because they are more acutely aware of any mistakes they make, even though, objectively speaking, their performance hasn’t gone downhill at all. “In a real sense, mothers may go through a phase where their brains are working more slowly. Babies aren’t rocket scientists and their brains process at a moderate speed. Hormonal influences slow down the mother’s brain to sync it with the baby’s more effectively. I don’t think the mother’s brain is dumbed down, just refocused on the priorities associated with caring for the baby.”

Realities of the childbearing year

Another part, though, has to do with the physical realities of the childbearing year. Pregnancy can be tiring; you may also be suffering from morning sickness or dealing with other complications. Once the baby is born, you may be up several times during the night and barely have a moment to shower or eat during the day. Who wouldn’t get a lower test score if she was throwing up three times a day or surviving on less than five hours of sleep?

Nast, in fact, bristles at the whole suggestion that mothers can’t think as well as they used to. “I think this idea is used to diminish women — oh, you can’t have much of a career or accomplish things because you have mommy brain. If I do forget something, maybe it’s because I’m exhausted from getting up six times a night and not having the help and support that I need so that I’m trying to remember everything, not because my brain was somehow turned to mush by my hormones.”

Buckley points out that evolution would support new mothers having smarter brains, not slower ones. They need to be able to manage the responsibilities they had before baby arrived and add several new skills to meet baby’s needs. He points out that when women process information, more areas of the brain are activated than when men process the same data. These active areas in a woman’s brain also have more communication between them. Buckley says this may explain why women tend to be better at multi-tasking. After you have a baby, being able to multi-task becomes essential: It’s an everyday thing to be reading a book to your toddler while adjusting your newborn’s latch at the breast and keeping an eye on the potatoes boiling on the stove, while mentally estimating how long it will take to cook up the burgers.

“For me, going back to school affirmed all these new skills I learned through mothering,” says Nast. “Mothers have to be good at adapting and organizing and doing several things at once.”

Buckley agrees. “I think Katherine Ellison may have just grazed the surface, and future research will show us just how amazinglyence of motherhood.”

Mommy brains

The truth seems to be that having a mommy brain isn’t such a bad thing. Your mommy brain can distinguish your newborn’s smell and cry from that of any other baby, can hear the faintest little “I’m waking up” noises even when you’re sound asleep, and can master the new tasks of baby care, feeding and promoting infant development despite being chronically tired. And if this is your second, third or later child, your brain will do all that while also paying attention to the needs of your older children.
Pretty impressive, that mommy brain. Just the kind of brain a prime minister needs, don’t you think?

This article was originally published on Aug 04, 2008

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