New study stresses importance of blood pressure control in pregnancy
Hypertension is a not uncommon pregnancy complication that affects the health of the mother and her developing fetus. A new study has uncovered another negative outcome of the condition: life-long cognitive deficits in offspring. European researchers published the results of their study online on October 3 in the journal Neurology.
The investigators noted that hypertensive disorders, including chronic hypertension, gestational hypertension and preeclampsia, complicate about 10% of all pregnancies. They evaluated whether maternal hypertensive disorders in pregnancy predict age-related change in cognitive ability in the offspring throughout life (up to old age). They reviewed maternal blood pressure and urinary protein measurements from the maternity clinics and birth hospitals. They defined normotensive or hypertensive pregnancies in mothers of 398 men, who participated in the Helsinki Birth Cohort 1934–1944 Study. The men underwent the Finnish Defence Forces basic ability test twice: first during compulsory military service at age 20.1 years and then in a retest at age 68.5 years. The evaluation yields a total score and sub-scores for tests measuring verbal, arithmetic, and visuo-spatial reasoning.
The researchers found that men born after pregnancies complicated by a hypertensive disorder, compared with men born after normotensive pregnancies, scored 4.36 points lower on total cognitive ability at 68.5 years and displayed a greater decline in total cognitive ability (2.88) after 20.1 years. Of the sub-scores, associations were strongest for arithmetic reasoning.
The authors concluded that maternal hypertensive disorders in pregnancy predict lower cognitive ability and greater cognitive decline up to old age. They noted that their study suggested that a propensity to lower cognitive ability and decline up to old age may have prenatal origins.
The American Congress of Obstetrics and Gynecology (ACOG) notes that hypertension during pregnancy can lead to reduced blood flow to the placenta; thus, the developing infant is subjected to a decrease in oxygen and nutrients. When high blood pressure has been present for some time before pregnancy, it is known as chronic, or essential, hypertension. The condition remains during pregnancy and after the birth. It is extremely important to control hypertension because it can lead to a heart attack, stroke, or kidney failure.