Baby Brain: Is it Real?

Forgetfulness, loss of concentration, and memory problems are all common complaints of mothers-to-be and the so-called “baby brain.” For decades, it was dismissed as an old wives’ tale, but it’s actually a very real phenomenon. 

Baby brain affects women differently throughout their pregnancies, but is typically most noticeable during the first trimester. Women don’t feel as “sharp” or “put together” as usual when they are pregnant. This is particularly true because hormones change the most during the first trimester of pregnancy. 

Hormones, Pregnancy, and Baby Brain

In the first trimester, progesterone and estrogen, the hormones that affect your normal menstrual cycle, rapidly increase. A new hormone called human chorionic gonadotropin is created. 

Progesterone is associated with irritability and when the levels of this hormone remain high, mood swings are the result. 

Estrogen helps to regulate progesterone while maintaining vital elements of the baby’s development. Estrogen also increases blood flow to help nourish the baby, but can lead to aching and tender breasts and more urgent bathroom breaks. The estrogen-induced blood flow is also the reason for why you may have that healthy pregnancy glow. 

Studies have been done to determine exactly what causes brain fog during pregnancy. There is a lot of speculation, but there is research surrounding the brain matter that shows proof. Gray matter volume is affected during and after pregnancy. 

A study in Nature Neuroscience used an MRI to scan the brains of 25 pregnant women before and after pregnancy. The results showed that gray matter reduces in brain regions closely tied to processing information, and promotes bonding between the mother and baby. 

The gray matter reductions do not mean that pregnant women “lose function,” but it is actually their brain preparing for motherhood. This “fine tuning” of the brain helps women raise children by allowing their brains to adapt and expand into their new roles as mothers. 

What Causes Baby Brain?

It’s completely normal to be forgetful or scatterbrained when you’re busy, stressed, or tired – all things moms-to-be experience. When you are not getting enough sleep and multitasking, no one has a perfect memory. 

However, surging hormone levels and shifting to new priorities may also explain why baby brain happens. There is 15-40 times more progesterone and estrogen in the brain during pregnancy. These specific hormones affect neurons in the brain. When a woman delivers a baby, there are massive surges of oxytocin in the brain that allows the uterus to contract and the body to create milk, but it also affects circuits in the brain. 

Being pregnant doesn’t change your IQ, but your priorities do. Think of your brain like a closet – there are only so many shelves in a closet, and the top 3 are now filled with baby stuff. That doesn’t leave a ton of extra space for other day-to-day things. The good news is that your brain will revert to its “normal” function, yet don’t be surprised when it doesn’t happen quickly. Children will change your priorities, but your actual brain function will remain the same.