Why this occurs is still unknown, but various theories exist. The most promising of these theories is related to a pre-existing link between cardiovascular (heart) health and cognitive (brain) health.
With this in mind, anyone who experiences high blood pressure in pregnancy should remain in regular contact with a healthcare provider and take preventative action to keep their cardiovascular health in good shape.

What the Study Showed

The aforementioned study looked at 596 women, approximately 15 years post pregnancy. Eighteen percent of women in the study had experienced high blood pressure in their pregnancy, while the remaining women had normal blood pressure. Researchers conducted a series of tests to assess cognitive function in women, and compared the results between those who had experienced high blood pressure in pregnancy and those who had not. Many of the tests revealed similar cognitive abilities between the two groups when all variables were considered. However, memory and verbal learning were subtly worse in women who had experienced high blood pressure in pregnancy. Co-author M.A. Ikram, MD, PhD explains that verbal learning is a part of memory. “Verbal learning is part of memory and pertains to learning something through (listening/reading) words," he says. “This is as opposed to visual memory or memory of other non-verbal types.” Ikram explains that, although this particular study has shown only subtle deficits in memory and verbal learning, it is important to follow the study participants later into life to assess if hypertensive disorders of pregnancy affect the long-term risk of dementia or further cognitive decline. He says, “Hypertensive complications during pregnancy can have a long-term effect. Together with their treating physician, [women] should therefore take extra care to maintain their cardiovascular and brain health.”

Hypertensive Disorders of Pregnancy

In the study above, hypertensive disorders of pregnancy included both gestational hypertension and pre-eclampsia. Study authors defined these as:

Gestational Hypertension: A new onset of blood pressure greater than 140/90 after 20 weeks of pregnancy, without any evidence of protein in the urine. Pre-eclampsia: A new onset of high blood pressure greater than 140/90 after 20 weeks of pregnancy, with evidence of protein in the urine.

Researchers do not yet know how memory loss is caused by hypertensive disorders of pregnancy. However, various theories exist, and a growing body of research shows that cardiovascular diseases increase the risk of cognitive decline later in life. Neuroscientist Dr. Kristen Willeumier explains that it is the lack of quality blood flow through blood vessels in the brain that leads to deficits in memory and learning. “One of the best ways to prevent memory decline is to protect your cardiovascular health, as poor cerebral circulation will lead to cognitive decline,” she says. “Anything that can damage your blood vessels is destructive to your cognitive function.” According to the American Heart Association, high blood pressure damages the blood vessels by making them less elastic. Loss of elasticity can lead to small ruptures of the vessels, deposits of plaque to heal these ruptures, and subsequent narrowing of the vessels.  All these combined means that they are less able to carry nutrient-rich blood and oxygen to vital organs, including the brain. Ikram adds, “We know that different cognitive domains are served (at least partly) by different regions in the brains. It is possible that those regions relevant for memory may be most susceptible to the hypertensive damage.”

How to Prevent Memory Decline

If you have experienced hypertension in pregnancy, rest assured that there are ways to protect your cognitive health. Prevention is key to avoiding memory decline. Willeumier provides us with 10 key areas to consider to maintain strong working memory and learning ability throughout your life. She recommends:

Maintain a Healthy Weight

“You want to get your body mass index (BMI) into the healthy range (19-24.9) as excess weight can damage the brain and shrink brain volume in key areas of the brain associated with learning and memory.  

Consume a Brain-Healthy Diet

The Mediterranean and MIND diets have both been demonstrated in the scientific literature to protect both cardiovascular and neurological health. Brain-healthy foods include avocados, wild salmon, kale, spinach, broccoli, blueberries, sweet potatoes, lentils, quinoa, wild rice, walnuts, chia seeds, flax seeds, dark chocolate, and green tea. Despite being a flawed measure, BMI is widely used today in the medical community because it is an inexpensive and quick method for analyzing potential health status and outcomes.

Nutritional Supplementation

Everyone over the age of 40 should take a high potency multivitamin (it preserves telomere length and helps the body to maintain production of neurotransmitters), omega 3 fatty acids and optimize their vitamin D levels.  Eat 2 servings of fatty fish per week or take a high-quality omega 3 fatty acid supplement. Folate and vitamin B are critical to neurological health. Low levels of vitamin B, D, and omega 3 fatty acids have all been associated with mood disorders or cognitive decline.

Adequate Hydration

Water is vital to human life. It is involved in every chemical reaction that occurs in the brain. We need it to maintain our health and vitality and when we don’t consume enough, we can down-shift into suboptimal health quickly. Your body is 75% water and the average American (up to 75% of us) are slightly dehydrated.

Get Restorative Sleep

During sleep, we clear the brain of harmful plaques and proteins that can lead to Alzheimer’s disease. It also is a time when we consolidate memories from short-term to long-term storage, which means it is critical to forming and maintaining cognition. 

Maintain a Healthy Blood Pressure

One out of three adults has high blood pressure. This weakens the blood vessels and can lead to vascular dementia.

Treat Depression

Depression is a mood disorder that is linked to poor health, social isolation, and cognitive decline.

Daily Exercise

Physical activity leads to increased gray matter in the brain, particularly in areas associated with learning and memory. It supports the health and integrity of the blood vessels responsible for bringing oxygen-rich blood and nutrients to the brain.

Cognitive Training

Lack of stimulating cognitive activity can lead to a decrease in cognitive reserve. Mentally stimulating activities increase synaptic activity and can lead to synaptogenesis and neurogenesis.

Stress Reduction and Self-Care

In addition to these steps, Willeumier reminds moms that stress reduction and self-care are important in maintaining good blood flow to the brain. “Make time for yourself,” she says. “Self-care is essential as it shows self-love, which will give the strength and vitality to successfully manage all of the responsibilities of being a mom.”