Researchers found evidence that women who gave birth to boys outperformed moms of girls in tests taxing memory in areas of listening, computational and visualization skills.
The 18-month study tracked 39 Vancouver-area women from early pregnancy to several months after child birth. Tests were given repeatedly during pregnancy and after.
"When we set out to look at the effects of pregnancy on cognition, we weren't thinking of the sex of the fetus, so we were shocked by our results," said study leader Neil Watson, a Simon Fraser University psychology professor.
Watson said results suggest an "unknown fetal-derived factor" may have an influence on the mother's cognition.
The researchers' findings will be published in the May 12 findings of the journal NeuroReport.
