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The Biology of the Mommy Mind

The Biology of the Mommy Mind

Pregnancy and parenthood can be incredibly stressful, as moms in the Stressful Pregnancy community on Circle of Moms well know. And the stress doesn’t go away when the baby is born. Understanding what’s going on in your body, as well as sharing ideas with others on how to relax when things get tough can both help you keep it all in perspective.

In most cases, people are pretty good at prioritizing life's stresses. We all know the difference between big stresses (mounting debt) and small stresses (mustard stains). And even though small stresses can seem big at the time, we know deep down that at no time and in no world do condiments ever trump credit scores.

That all changes in pregnancy. Every stress feels like a big one, as your brain swirls and twirls and somersaults with more questions than a prosecuting attorney. We imagine that this sampling sounds a bit familiar to that voice in your head: Is my baby healthy? How hard is labor going to be? Can I afford child care? Will my mate look elsewhere now that I’ve lost my figure and I’m not as interested in sex? Does he really want to name the child after his favorite football player? Why are my parents hounding me to be in the delivery room? How are the siblings going to handle another child? Will I be like—gasp!—my mother?


These questions are meant to reinforce the fact that we know you have a lot of important issues on your mind, and it’s no wonder that you’re feeling such a psychological burden. These are tough questions, but one thing there’s no question about. Everyone has anxiety during pregnancy, especially during her first one. Of course, that’s because there’s a fear of the unknown the first time around (but also because there’s less time to be worried when you have other tykes to chase after). Moms explode with tension when presented with so many questions—and so many possible answers.

While you may already know what’s happening emotionally because your feelings and questions are as tangible as the slats on a crib, have you ever thought about what may be going on physically? Specifically, what happens deep inside your brain when you get pregnant? Lots of things, actually.

For one thing, your brain actually shrinks during pregnancy. That’s not surprising for those of you who’ve experienced mommy brain: You dump chili powder on ice-cream sundaes or make some other kind of mental mistake; it’s a kind of subtle forgetfulness. Your brain doesn’t lose cells per se, but as your metabolism changes; your brain restructures the connections between cells and changes in preparation for motherhood. Typically limited to the third trimester, this might actually have evolved as a way of preparing you to focus on your baby and block out lots of other worrisome thoughts, but it can be discomfiting just the same. In the final one to two weeks before birth, your brain will begin to increase in size again and build new maternal neural circuits, eventually becoming stronger than it was before and helping you to better understand and cope with your newborn.

For another, your brain requires additional fuel during pregnancy. The major chemical player here comes in the form of DHA, the critical omega-3 fatty acid in both your child’s brain, as mentioned in the last chapter, and your own. Fetuses are pretty assertive when it comes to taking those omega-3 fatty acids. Because the brain is 60 percent fat,* you’ll be depleted of those important neuron-protecting fatty acids unless you make a point of getting them through diet or supplements. DHA seems to help repair your brain cells or connections damaged by stress: Studies of stressed out cab drivers show that they coped better when they took extra omega-3 fatty acids. We recommend that you take DHA supplements to help replenish your supply. DHA will help you prevent or cope with stress and manage depression as well.

Throughout pregnancy, a woman’s brain marinates in neurohormones manufactured all over her body, including her placenta, and those hormones wreak havoc on a mom’s senses and emotions. In the first few months of pregnancy, these chemical messages cause a woman’s sense of smell to change, making her sensitive to anything that might hurt the baby. This is one of the reasons why pregnant women get nauseated so easily. The brain gets used to those hormones, typically after the first few months, helping her want to eat again.

Two hormones in particular—progesterone and estrogen—go into overdrive during pregnancy. Progesterone provides a tranquilizing effect to protect against stress, one of the reasons why women can handle so much heavy thinking and anxiety during pregnancy.

Increased estrogen, which you may associate with more sexy topics, also plays a role in brain function. How? First, estrogen seems to protect neurons, preventing them from being damaged by outside influences (oxidative stress, for instance). Second, estrogen increases the effect of nitric oxide, a gas that widens blood vessels. Unlike many other organs, the brain doesn’t store excess fuel to any great degree. So your brain relies primarily on blood vessels to receive the fuel it needs to function. More estrogen means better blood flow; better blood flow means there’s a smaller chance that you’ll try to clean the bathrooms with banana peels.

In addition, during delivery, huge bursts of oxytocin run through the brain. Oxytocin is the feel-good hormone that helps us bond with others. In the days and weeks immediately before delivery, many women experience mild euphoria and also strong nesting behavior (inexplicably washing walls, baking, and so on), and this may be linked to oxytocin as well as to other hormones and steroids. After delivery, when a woman holds her newborn, she also gets what’s called “baby lust,” a chemical reaction that happens when a baby’s pheromones stimulate the production of additional oxytocin—thus augmenting that bonding feeling.

The effect of all the hormonal and neural changes during pregnancy is that the brain is really receiving a loud and strong message: Baby’s a‑comin’, and you need to be prepared. One of the side effects may be a bit of mind fog, and this may lead to a bit of stress: If I can’t remember where I left my shoes, how in the world am I going to care for a baby or function at my job when I go back to work? But take comfort in the fact that all of these changes not only are reversible, but are preparing you to be the best parent possible.

* Proving once and for all that we’re all fatheads.

A New York Times #1 best-selling author and host of The Dr. Oz Show, Mehmet C. Oz, M.D. is also professor and vice chairman of surgery at New York Presbyterian-Columbia University and the director of the Heart Institute. For more from Dr. Oz, check out You: Raising Your Child and You: Having a Baby, both co-authored with Michael F. Roizen, M.D.

The views expressed in this article are those of the author and do not necessarily represent the views of, and should not be attributed to, POPSUGAR.

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