If you think delivering that gorgeous baby means an automatic return to your former mental self, think again. "Pregnancy brain" is real, and it can affect your postpartum brain as well. In fact, half of new moms still felt super sleepy 18 weeks after giving birth, according to a recent study published in PLOS One. Here's what to expect.
Using magnetic resonance imaging, a team of British researchers led by London anesthesiologist Anita Holdcroft, M.D., scanned the brains of 10 pregnant women who were in their final two months of pregnancy and then again at two and six months postpartum. Holdcroft’s original objective was to look for swollen air passages and changes in brain size in pregnant women with preeclampsia. She was shocked to learn that instead of swelling, the subjects’ brains were smaller during pregnancy than after delivery. “Brain cell volume actually decreases in pregnancy,” Holdcroft says. “The changes are not that big, but they are measurable.” Speculating that hormonal alterations of brain metabolism are responsible for the shrinkage, Holdcroft found similar changes in brain volume in menstruating women. She since has launched a larger study of pregnant women to test the hormone theory.
The link between brain contraction and so-called “pregnancy-induced slowness” is not clear, but research conducted earlier this year by University of Southern California psychologist J. Galen Buckwalter, Ph.D., suggests that pregnant brains not only shrink, but they also suffer impaired cognitive functioning. Buckwalter, who has likened pregnancy to “a big assault on the brain,” tested 19 highly educated pregnant women whose average IQ was about 110. He found that all of the subjects had experienced depressed functioning of their concentration and short-term memory. In addition, the women’s ability to learn and retain new information was reduced. In a test of how well pregnant vs. non-pregnant women with similar IQs learned new information, the pregnant subjects scored in the lowest 5 percent.
In addition to pregnancy hormones, Shannon Seip, co-author of Momnesia (Andrews McMeel Publishing) and a mother of two in Madison, Wisconsin, thinks sleep deprivation is a factor of pregnancy brain. "Since I adopted my second child, I didn't have the issue with hormones that I did with my first," she says. "But I was definitely sleep-deprived, and I definitely had momnesia." (As proof of that, she points to the time when she arrived at work without her shoes.)
The huge learning curve of taking care of a newborn also contributes. "You're gathering so much new information, so worried about simply keeping your baby alive and well-fed, that it consumes your brain," Seip explains.
Brain shrinkage is part of the many normal body changes that take place in pregnant women, according to Holdcroft’s study. Thankfully, the gray matter seems to plump back up to normal size sometime after childbirth. Getting more of that ever-elusive sleep also helps.
Besides laughing it off, try to find comfort in the small triumphs. "You may not be able to remember your husband's name," Seip says, "but take pride in the fact that you know your pediatrician's phone number by memory or that you can operate your breast pump with your eyes closed."
Also take advantage of a few memory joggers. Leave yourself voicemails; write notes on your palm; keep a pen and paper in several places so you can jot down important reminders. And if you're concerned about being able to find those reminders, place Post-its in a prominent place. "One mom put them on her baby!" Seip says.