Mom's high blood pressure in pregnancy could affect child's IQ into old age

"High blood pressure and related conditions such as preeclampsia complicate about 10 percent of all pregnancies and can affect a baby's environment in the womb," said study author Katri Räikönen, PhD, with the University of Helsinki in Finland. "Our study suggests that even declines in thinking abilities in old age could have originated during the prenatal period when the majority of the development of brain structure and function occurs."

Researchers looked at medical records for the mother's blood pressure in pregnancy for 398 men who were born between 1934 and 1944. The men's thinking abilities were tested at age 20 and then again at an average age of 69. Tests measured language skills, math reasoning and visual and spatial relationships.

The study found that men whose mothers had high blood pressure while pregnant scored 4.36 points lower on thinking ability tests at age 69 compared to men whose mothers did not have high blood pressure. The group also scored lower at the age of 20 and had a greater decline in their scores over the decades than those whose mothers did not have problems with blood pressure. The finding was strongest for math-related reasoning.

The researchers also looked at whether premature birth affected these findings and found no change. Whether the baby's father was a manual laborer or an office worker also did not change the results.