Pregnancy can bring along a lot of physical as well as hormonal changes in the body. While these changes are necessary for proper growth and development of the baby, there are certain complications that may arise. One of these is high blood pressure in pregnant women, which is medically called hypertensive disorders during pregnancy (HDP).
Studies have shown that hypertensive disorders can result in various neurovascular complications such as eclampsia (seizures during pregnancy), stroke, cerebral oedema, and intracranial haemorrhage (bleeding inside the brain). Recent studies have shown that women suffering from hypertensive disorders during pregnancy are more likely to experience cognitive impairment later in life. Cognitive impairment is a term used to determine a state of confusion, loss of memory, inability to understand things or make decisions and dementia.
Hypertensive disorders during pregnancy
Hypertension (high blood pressure) is one of the most common medical issues experienced by pregnant women, which complicates around 6-8% of the pregnancies.
Note: As per the World Health Organization (WHO), the normal range of blood pressure should be 120 mm Hg while the heart is beating (systolic) and 80 mm Hg while the heart relaxes (diastolic).
Hypertensive Disorders during Pregnancy (HDP) are classified into 3 categories:
- Chronic hypertension: It is the high blood pressure that can either be experienced within the first 20 weeks of pregnancy or does not resolve on its own by the 12th week after delivering. It can be mild (up to 179 mm Hg systolic and 109 mm Hg diastolic) and severe (more than 180 mm Hg systolic or 110 mm Hg diastolic).
- Preeclampsia: Preeclampsia is a pregnancy complication characterized by the high blood pressure (more than 140/90 mm Hg) along with protein release in urine after 20 weeks of pregnancy.
- Gestational hypertension: Previously known as pregnancy-induced hypertension, it occurs after 20 weeks of pregnancy marked with more than 140/90 mm Hg blood pressure.
Can high blood pressure during pregnancy cause cognitive impairment?
A number of studies have been conducted to determine the effects of HDP on the cognitive abilities of women. Some of these studies include:
- Scientists from the Erasmus University Medical Center, Netherlands conducted research on 115 women with a history of HDP and 481 women with normal blood pressure during their past pregnancy. Out of the 115 women with HDP, 80 women suffered from gestational hypertension while the rest 35 had preeclampsia. After a follow-up period of 15 years, women with HDP were found to have poor working memory and verbal learning skills. The study published in the journal Neurology further concluded that the risk was higher in women with gestational hypertension.
- Another study published in the American Journal of Obstetrics and Gynecology conducted research to determine if a history of preeclampsia increases the risk of cognitive impairment 35 to 40 years after the pregnancy. Out of the total 80 women included in the study, 40 had a history of preeclampsia while the other 40 had normal blood pressure in their past pregnancy. The results of the study showed that women with preeclampsia showed more cognitive decline later in life than those who had normal blood pressure.
- A study published in the Journal of the American Heart Association included 193 women with a history of preeclampsia and 375 women with normal blood pressure during pregnancy and followed them up 18 years after the delivery. The results of the study showed that women with preeclampsia had increased risk of developing dementia and showed reduced cognitive abilities as compared to women with normal blood pressure during pregnancy.
Ways to keep blood pressure at bay during pregnancy
Genetics and medical history related to past pregnancies have a major role in determining the risk of hypertension in a pregnant woman. Thus, hypertensive disorders cannot be completely prevented. However, they can be managed by making simple lifestyle changes such as:
- Increasing the intake of water to keep the body hydrated.
- Reducing salt intake, which is hidden in processed foods.
- Consuming a diet rich in fruits, green vegetables, lentils and whole grains.
- Regularly practicing mild-intensity exercises such as walking, yoga, and pilates to prevent obesity.
- Quitting smoking and alcohol consumption until the baby is born.
- Going for regular prenatal checkups and getting blood pressure screened regularly.
Hypertensive disorders can be dangerous during pregnancy as disorders like preeclampsia cause a sudden spike in the blood pressure, impairing the body’s ability to maintain normal and stable blood flow to the brain, leading to a neurovascular complication. Similarly, both gestational hypertension and preeclampsia have been associated with developing heart disease (atherosclerosis) in otherwise healthy pregnant women.
Scientists believe hypertension during pregnancy can be prevented and treated easily by bringing healthy change in the lifestyle and by closely monitoring the blood pressure during pregnancy. Women experiencing any abnormal symptoms (severe headaches, blurred vision, sudden swelling of ankles and feet) must report it to their doctor to ensure their own good health and that of their baby.