A study published in Hypertension examined the effect of elevated blood pressure prior to pregnancy on miscarriage risk.
Researchers examined 1,228 women who had already experienced one or two miscarriages who were trying to become pregnant. They measured the women's blood pressure while they were trying to become pregnant and during early pregnancy.
Of the 797 women who conceived within six months, 24 percent suffered a miscarriage. Researchers found a 10-point increase in diastolic blood pressure correlated with an 18 percent increased risk of miscarriage. Additionally, every 10-point increase in mean arterial pressure correlated with a 17 percent increased risk of pregnancy loss.
Study authors did caution, however, a cause-and-effect conclusion could not be reached. They noted since the study only included women who had experienced a miscarriage, it was unclear if the results could be generalized to all women.