No statistically significant associations were observed between parity and stroke risk in a diverse cohort of US women, a recent study found. Researchers assessed the association between parity and incident stroke among 7,674 white and 6,280 black women, aged ≥45, and enrolled in the REasons for Geographic and Racial Differences in Stroke Study from 2003 to 2007. They found:

• At baseline, 12.7% of white women and 16.2% of black women reported 1 live birth, while 8.2% and 19.0%, respectively, reported 5 or more live births.
• Mean follow-up time was 7.5 years (standard deviation=2.8); there were 447 incident strokes.
• Among white women, those with 5 or more live births had a higher stroke risk than those with 1 live birth. However, the association was eliminated after adjustment for baseline characteristics.
• For black women, those with 5 or more live births had the highest stroke risk compared with those with 1 live birth, but the association was attenuated and no longer statistically significant after adjustment for confounders.