The prevalence of hypertension during pregnancy has spiked in the U.S. since 1979. A new study has found an increase in the number of pregnant women with high blood pressure (HBP).
These women may get hypertensive before pregnancy or during the first twenty weeks of pregnancy. While the rate of HBP is twice in black women in contrast to white women. The journal Hypertension has presented this new research.
Hypertension and the risk of complications during pregnancy
Having HBP before or during pregnancy can lead to complications for both women and unborn babies. Hypertension in pregnancy can increase the risk of infant death or stillbirth and preeclampsia. It may also enhance the odds of stroke, heart failure, heart muscle disease, or kidney failure.
Besides these, HBP can also heighten the risk of death in pregnant mothers. The research team has defined HBP as a systolic blood pressure of 140 mm Hg and a diastolic blood pressure of 90 mm Hg. In contrast, the American Heart Association has defined HBP differently.
The AHA states that 130 mm Hg systolic blood pressure and 80 mm Hg diastolic blood pressure denotes high blood pressure. Where systolic pressure is the top number in blood pressure reading. And the bottom number shows the reading of diastolic blood pressure.
Many studies have told about the negative impacts of hypertension during pregnancy. Women who have HBP and are planning to get pregnant should work with their health care providers to monitor and control their blood pressure. Monitoring blood pressure is more vital during pregnancy, to lower the risk of many health issues in both mothers and unborn children.
Rates of chronic hypertension during pregnancy
In this study, the research team has analyzed the rates of chronic hypertension during pregnancy. While chronic hypertension is defined as having high blood pressure prior to pregnancy or during the first 20 weeks of pregnancy. The pregnant women included in this study had an age between 15 and 49 years.
The team has used the data from the CDC’s Disease Control’s National Hospital Discharge Survey (NHDS). And has analyzed nearly 151.5 million hospitalizations related to childbirth from 1970 – 2010. The team has also considered factors such as the mother’s age, race, and the year of delivery to assess the changes in chronic HBP.
The results of the study have shown that about 0.63% (1 million) of women suffered from chronic hypertension in pregnancy. And there was a sharp increase in these rates with the mother’s age and year of delivery. The rates have spiked from 0.11% in 1970 to 1.52% in 2010. That is about 13 times increase in the past four decades.
The research team has found that mothers who were older at the time of pregnancy were more likely to have chronic HBP. It suggests that advance maternal age has a strong association with chronic high blood pressure. And pregnant mothers should be aware of the risks associated with chronic hypertension.
Moreover, the results have also shown that the rates of HBP in black women are twice than white women. Originally, the team thought that higher rates of smoking, obesity, diabetes, and vascular disease in black women may explain these racial differences.
But after adjusting smoking and obesity rates, the team found that these factors play no role in the upward trend of HBP during pregnancy. Despite these results, smoking and obesity are considered strong risk factors for high blood pressure.