A study published in March, Parity and risk of hemorrhagic strokes (Jung et al), has reported that: "Increased number of childbirths may be related to an increased risk of both intracerebral hemorrhage and subarachnoid hemorrhage."
An article on the study, Multiple childbirth linked to stroke risk, in the March issue of Neurology, explains this finding in more detail:
"Pregnancy and delivery are known to raise stroke risk. To further look into the association between multiple births and stroke risk, researchers compared 459 women who had stroke and 918 who did not. The women were about 56 years old on average at the time of the study.
Among women who had a stroke, 38 had zero or one childbirth, 143 had given birth twice, 107 had given birth three times, and 171 had four or more deliveries. After allowing for many other factors associated with stroke risk such as age, family history of stroke, high blood pressure, diabetes, cigarette and alcohol use, as well as oral contraceptive and hormone replacement use, each additional birth was associated with 27 percent greater risk for stroke. Women reporting four or more childbirths had nearly a threefold higher risk of stroke as women with no childbirths or childbirth.
The findings could be attributed to the speculation that multiple births might further strain and stress blood vessels and other body systems, and the stress of raising children may also raise stroke risk."