Researchers from the University of Helsinki in Finland found that men whose mothers had high blood pressure while pregnant scored lower on thinking ability tests and performed poorly in math-related reasoning.
"High blood pressure and related conditions such as preeclampsia complicate about 10 per cent of all pregnancies and can affect a baby's environment in the womb," said study author Katri Raikonen.
"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," Raikonen said in a statement.
The study 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.
Researchers 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 labourer or an office worker also did not change the results.
The study was published in the journal Neurology.
