High BP during pregnancy tied to memory and cognitive decline later, finds study
Women who develop high blood pressure during pregnancy may be more likely to have lower scores on tests of memory and thinking skills 15 years later than women who did not develop high blood pressure during pregnancy, according to a new study published in the December 30, 2020, online issue of Neurology®, the medical journal of the American Academy of Neurology.
"Women with high blood pressure that starts in pregnancy, as well as women with pre-eclampsia, should be monitored closely after their pregnancy and they and their physicians should consider lifestyle changes and other treatments that may help reduce their risk of decline in their thinking and memory skills later in life," said study author Maria C. Adank, M.D., of Erasmus University Medical Center in Rotterdam, the Netherlands.
The study involved 596 women who were pregnant at the start of the study. A total of 481 women had pregnancies with normal blood pressure and 115 women developed high blood pressure problems during pregnancy. Of those, 70% had gestational hypertension, which is high blood pressure that starts after 20 weeks of pregnancy in women who previously had normal blood pressure. The other 30% had pre-eclampsia, which was defined as high blood pressure along with increased protein levels in the urine that develops after 20 weeks of pregnancy.
Fifteen years after the pregnancies, the women took tests of their thinking and memory skills.
The women who had high blood pressure in pregnancy were more likely to have lower scores on a test of immediate recall and delayed recall. The test asks people to remember a list of 15 words, first right away and then after waiting twenty minutes.
On the immediate recall test, which was given three times, the women with no high blood pressure problems 15 years earlier scored an average of 28 points out of a possible high score of 45, while the women who had high blood pressure in their pregnancies 15 years earlier scored an average of 25 points. Women with high blood pressure in their pregnancies performed worse on the immediate and delayed recall task after researchers adjusted for other factors that could affect thinking skills, such as body mass index before pregnancy, education level and ethnicity.
There was no difference between the two groups of women on tests of fine motor skills, verbal fluency, processing speed and visual-spatial ability.
"It's important to consider gestational hypertension and pre-eclampsia as risk factors for cognitive impairment that are specific to women," Adank said. "Many women may think of this as a temporary issue during pregnancy and not realize that it could potentially have long-lasting effects. Future studies are needed to determine whether early treatment of high blood pressure can prevent cognitive problems in women with a history of high blood pressure in pregnancy."
Adank noted that the study does not show a cause-and-effect relationship between the high blood pressure and test scores. It only shows the association.
A limitation of the study is that no thinking and memory tests were taken before the women were pregnant or during pregnancy, so researchers could not look at the effects of a pregnancy complicated by high blood pressure on thinking skills within one woman.