As a child grows up, a mom's memory of the pregnancy and delivery tends to fade over time. But some pregnancy complications may be important to recall later.
A recent study found that women who had high blood pressure disorders during pregnancy may have an increased risk of stroke later on.
The evidence showed the strongest link for stroke risk among mothers who had had pre-eclampsia while pregnant.
Pre-eclampsia is a pregnancy complication in which a woman has high blood pressure and protein in her urine. It can become very serious, and the only treatment for pre-eclampsia is to deliver the baby.
This study, led by Aravind Ganesh, a neurology resident at the University of Calgary, aimed to find out whether women who had high blood pressure disorders during pregnancy were at a higher risk for stroke later on.
The researchers examined all the studies they could find that were in two medical research databases and related to high blood pressure disorders during pregnancy and stroke risk.
They also looked through conference proceedings and clinical trials registries to see if they could locate unpublished studies.
They identified nine studies that met their criteria. Two of these studies followed women forward in time from their pregnancies. Four studies looked back on women's histories to establish possible risk connections. The other three studies compared women with different histories.
Some of the studies followed women for only one year, while others followed them for much longer — one up to 32 years after pregnancy.
The results of these studies showed that women who experienced a high blood pressure disorder during pregnancy were at higher risk for stroke later on.
This increased risk existed across international studies and regardless of a woman's race or ethnicity.
Dr. Ganesh said in a prepared statement that the studies pointed to an increased risk of stroke as high as 40 percent for some pregnancy disorders involving high blood pressure.
The pregnancy disorder that was most closely associated with an increased risk of stroke was pre-eclampsia.
During pre-eclampsia, a woman has protein in her urine in addition to having high blood pressure. The cause of pre-eclampsia is unclear, but the only currently known way to treat it is for a woman to have her baby.
When the researchers looked at the risk of stroke associated with having high blood pressure on its own during pregnancy — without pre-eclampsia — the evidence was weaker.
The data did not as strongly support a link between high blood pressure by itself during pregnancy and a later risk of stroke.
"These women should be more closely followed for a re-emergence of hypertension, as well as for cholesterol, diabetes or other markers of increased risk of stroke," Dr. Ganesh said in his statement.
This research was presented October 18 at the Canadian Stroke Congress. This study has not yet been published in a peer-reviewed journal, and its findings should be interpreted with caution.
Information on funding was unavailable. The authors declared no conflicts of interest.