Two weeks after giving birth earlier this year, Timeia Thompson's head throbbed, and she couldn't turn her neck. Her doctors thought the 34 year old most likely pulled a muscle while taking care of her newborn, and they sent her home with heating pads.
“I kept telling them something was wrong with me, and they just would not listen,” says Thompson, a mother of five who lives in Pittsburgh. “I literally have enough heating pads at my house to last me a year.”
Because of elevated blood pressure post-birth, Thompson was prescribed medication and enrolled in the hospital's hypertension program. Still, her blood pressure remained uncontrolled, and her head and neck pain persisted.
Then Thompson did her own online research and read about a woman with similar symptoms who'd been diagnosed with vertebral artery dissection, a rare occurrence during pregnancy and postpartum that can have fatal consequences. Thompson went to the ER and asked for brain vessel imaging. Doctors gave her the test, but as she waited for the results, one nurse said, “I don't know what you think we're going to find that we didn't find before.”
But it turned out Thompson's instincts were right: She had bilateral vertebral artery dissections and could have had a serious stroke at any time.
Thompson's experience is, unfortunately, not unique. Eliza Miller, MD, FAAN, chief of women's neurology at UPMC and the University of Pittsburgh School of Medicine, says she's seen this condition, and its unfamiliar symptoms, initially dismissed before.
“Our hope is to change that by educating the clinicians and the patients about these conditions, saying, ‘Look, here are some symptoms you cannot ignore,’” Dr. Miller says. “There's an opportunity to educate people that if you are having high blood pressure and a really bad headache in the postpartum period, you have to go to the hospital.”
Effects on the Brain
Many of the physical strains pregnancy can cause—discomfort, weight gain, uncomfortable swelling—are easy to see and largely known. But less is understood about how pregnancy affects the brain not only during gestation but in the months and even years after.
“We actually know very, very little about how pregnancy affects the brain in women because it's just been such an incredibly neglected area of research for so long,” Dr. Miller says. “I like to joke with my students that outside of the field of neurology, everybody is terrified of the brain. Outside of obstetrics, everyone's terrified of pregnancy.”
While it's still rare to have a stroke associated with pregnancy, a pregnant woman has about triple the stroke risk of someone in similar health who is not pregnant. One contributing factor is that blood becomes more likely to clot during pregnancy, a physiological adaptation as the body prepares to give birth to prevent excessive bleeding.
Some women develop preeclampsia (uncontrolled hypertension with protein in the urine and possible organ damage), which usually occurs after 20 weeks’ gestation but also can happen postpartum. “The risk does not go away once the baby is delivered,” Dr. Miller says. Women who have gestational hypertension, preeclampsia, or eclampsia (seizures that happen with preeclampsia) have an increased risk of developing neurologic disorders in the years following childbirth, according to the Preeclampsia Foundation. There also are indications that someone who has preeclampsia or even the more mild gestational hypertension has an elevated risk of stroke later in life.
“And by ‘later in life,’ I don't mean when you're 80. I mean when you're 45 or 50,” Dr. Miller says, adding that she has seen a lot of women in midlife who have strokes after having a history of high blood pressure during pregnancy.
Taking folic acid—a synthetic form of folate, a B vitamin found in leafy greens and other foods—prior to and during pregnancy can help prevent neural tube defects, such as spina bifida, in the baby, but it also can benefit the mother. Folate deficiency has been linked to a higher risk of dementia and decreased brain function; folic acid supplements, however, can improve that function, reduce symptoms of depression when taken with antidepressants, and potentially lower stroke risk by 10 percent, a report by UCLA Health notes.
More researchers likely will study the brain before, during, and after pregnancy as medical professionals continue to recognize the need for more data about this population. About six years ago, University of California, Irvine, neuroscientist Elizabeth R. Chrastil, then 38, offered herself as a test subject. She underwent 26 MRI brain scans paired with blood draws starting three weeks before she conceived her child and ending two years after she'd given birth. Then she and a team of researchers examined these never-before-gathered data sets and launched the Maternal Brain Project, an international effort to map the brain throughout pregnancy in different populations.
One of the first papers stemming from that project, published in Nature Neuroscience in September 2024, noted that few regions of the brain were “untouched by the transition to motherhood,” with physical changes occurring in brain matter. The tests also revealed that “highly dynamic changes” occur in the mother's brain during pregnancy, and some of those changes remain traceable decades later.
Existing Conditions
For women with migraine or other neurologic conditions, planning ahead and becoming more involved in their healthcare during their child-bearing years can help ensure that they and their children have the best possible outcomes.
“The best ways to mitigate risk are to have control of your neurological disease before [pregnancy] and to plan with your neurologist, ‘Which medicines can you stay on? How do we manage this postpartum?’” says Mary A. O’Neal, MD, FAAN, chief of general neurology at Brigham and Women's Hospital in Massachusetts. “Think through some of the common things that can happen. Planning around common complications and thinking through how to manage them is 100 percent the way to go.”
Kimford J. Meador, professor of neurology and neurosciences at Stanford University and clinical director of the Stanford Comprehensive Epilepsy Center, discusses the topic with all patients of child-bearing age. When dealing with teenagers and their parents, he puts it this way: “Nobody wants you to get pregnant any time soon, but some time in the future you might want to get married and have a child, and so we've got to start making decisions now to put you in the best place for that later.’ I've never gotten pushback.”
Dr. Miller asks all of her patients of reproductive age about what they use for contraception: “And if they say, ‘Nothing,’ I say, ‘Oh, so you're planning a pregnancy?’ Because then we need to have this conversation.”
Less than a century ago, patients with epilepsy were discouraged from having children at all, but doctors now know that more than 90 percent of women with epilepsy can have normal pregnancies and healthy children, Dr. Meador says. If doctors can keep a patient's antiseizure medication blood levels about the same as they were prior to pregnancy, women with epilepsy do not have an increased risk of seizures compared to non-pregnant women with epilepsy. Research also has shown that if a woman can find a suitable medication regimen that controls seizures for nine months before conception, it's likely she will be seizure-free throughout the pregnancy.
“The safest time to make changes is before pregnancy,” Dr. Meador says. “It's like that old saying about not wanting to switch horses mid-stream because you don't want to fall in the water.”
When doctors analyze the pros and cons of certain medications, they also look at the why, Dr. O’Neal says. She cited valproate, a commonly used antiseizure medication in the 1990s, and its high risk of congenital malformation in pregnancy as an example. If a woman takes it for migraine control, it's likely she can find another drug to replace it. But if she takes it because she has uncontrolled tonic-clonic seizures, that's a very different story.
“You have to look at each thing individually,” Dr. O’Neal says. “You can't just say, ‘Oh, we stopped all medicines.’ No, that we don't do. It depends on what the medicines are for, what the risk is, what the underlying condition is, and what other things have been tried.”
Another factor to consider is that pregnancy speeds up metabolism and changes the rate at which drugs are cleared from the body, Dr. Meador says. That's why doctors need to monitor antiseizure medication levels in pregnant patients with epilepsy on a monthly basis via blood draws and adjust dosages as needed, he says. The levels of certain antiseizure medications, such as lamotrigine and levetiracetam, in the blood can drop quite a bit during pregnancy, while others, including carbamazepine, tend to remain fairly stable.
Valproate carries significant risks of congenital malformations and cognitive impairment—including but not limited to autism spectrum disorder—in children born to women treated with the drug while pregnant. Although the drug is not used as much today, women who take valproate should know about the risks it poses to fetuses, Dr. Meador says.
Not every woman with a neurologic condition experiences problems during pregnancy, however. For some, pregnancy might actually improve their situation. Patients with multiple sclerosis (MS), for example, may experience a lower risk of disease relapse during pregnancy and especially in the third trimester, a 2024 study in Neurology noted. MS does often reactivate or rebound during the first three months after delivery, however, although this likely depends on several factors, including how active the disease was prior to pregnancy, the use of disease-modifying therapies before and after pregnancy, and breastfeeding, according to the study.
Some women with neurologic conditions experience both positives and negatives during pregnancy. Dr. O’Neal used migraine as an example. Migraine attacks affect 1 in 7 people worldwide and nearly 1 in 5 women of reproductive age. But 60 to 70 percent of women say their migraine attacks resolve during pregnancy and particularly in the second and third trimesters, according to a 2024 study published in the journal Life.
At the same time, migraine attacks are three times more common in women than in men because of hormone fluctuations, and pregnancy is a time of changing hormones. Women who have migraine attacks, especially those who have ones without aura, may have more intense attacks during the first trimester because of changing estrogen levels. In most cases, the problem lessens during the second and third trimesters but often ramps up again postpartum. Sleep deprivation and stress also can increase their frequency.
Having a history of migraine attacks can be problematic, too. A 2023 study in Neurology found that women who had migraine attacks prior to pregnancy were more likely to develop gestational hypertension and preeclampsia and to have a preterm delivery than women without migraine. And another study, published in JAMA Neurology in 2020, found an association between migraine and an increased risk of stroke during pregnancy and postpartum.
For some patients who stop taking their migraine medications for safety during pregnancy, migraine attacks can be devastating, says Teshamae Monteith, MD, FAHS, FAAN, professor of clinical neurology and chief of the headache division at University of Miami Miller School of Medicine. Neurologists can help pregnant patients adjust their treatment if migraine attacks become problematic, though. Options include behavioral interventions, neuromodulation devices, acupuncture, and even some oral preventive treatments, such as beta blockers and triptans.
Dr. Miller advises that patients talk to their medical team before making any changes to their treatment, adding that a partnership between the patient, their obstetrician, and their neurologist is the best way to avoid complications.
“What we don't want is for you to suddenly stop, for example, your antidepressants then become severely depressed,” she says. “That is not good for you, and that's not good for your baby either. Many of these medications are actually safe during pregnancy.”
What Is ‘Pregnancy Brain’?
A common pregnancy phenomenon women experience known as “pregnancy brain”—which usually refers to problems with focusing or memory—seems to be more complex than initially thought. While MRIs of women with “pregnancy brain” don't reveal structural normalities, it is a real experience likely caused by hormonal changes, stress, lack of sleep, depression, or anxiety rather than visible changes in the brain, says Mary A. O’Neal, MD, FAAN, chief of general neurology at Brigham and Women's Hospital in Massachusetts. Eliza Miller, MD, FAAN, chief of women's neurology at UPMC and the University of Pittsburgh School of Medicine, says sleep may play a particularly large role in the feeling, too.
“Everyone who's ever been through a period of their life when they didn't get much sleep knows that that really messes you up … [and] can contribute to the feeling that you're walking in a fog, that you can't remember anything, you can't concentrate,” Dr. Miller says. “Usually my message for patients who come to me and say, ‘Look, my brain is just not working anymore. I think I have dementia,’ is, ‘It's going to be okay. This is not a symptom of dementia. This is a transient state.’”
