There is a rapid rise in the number of women being diagnosed with hypertension or high blood pressure during pregnancy in the United States, a study has found. The number has spiked over the last four decades.

The study published in the medical journal of American Heart Association called Hypertension on Monday looked into the changes in the prevalence of chronic hypertension in pregnancy among American women between the years 1970 and 2010.

Hypertension is one of the most common health problems associated with pregnancy. Nearly 10 million women worldwide develop this condition during the most sensitive period in their life. It is associated with several potential complications for an expecting mother and her child.

For an expecting mother, gestational high blood pressure is associated with heart failure, stroke, kidney failure or cardiomyopathy, preeclampsia and even death. For an unborn child, hypertension in pregnancy increases the risk of stillbirth or newborn death.

“Women who already have high blood pressure and are planning to become pregnant should work closely with their health care provider to closely monitor and manage their blood pressure, especially during pregnancy, to reduce the serious health risks to both themselves and their unborn child,” lead researcher Cande V. Ananth, who is a professor and chief of the Division of Epidemiology and Biostatistics in the Department of Obstetrics, Gynecology and Reproductive Sciences at Rutgers Robert Wood Johnson Medical School in New Brunswick, New Jersey, said in a statement.

The American Heart Association defines high blood pressure as 80 mm Hg diastolic blood pressure and 130 mm Hg systolic blood pressure. The research team considered 90 mm Hg diastolic blood pressure and 140 mm Hg systolic blood pressure as high blood pressure.

For the study, the researchers analyzed data of nearly 151.5 million childbirth-related hospitalizations. All the information for the research was collected from the National Hospital Discharge Survey (NHDS) of Center for Disease Control.

During the study, the research team tried to look into the changes in chronic hypertension and they considered several factors that can cause high blood pressure, including the mother’s age, race and year of delivery.

The research team found an association between maternal age and the diagnosis of high blood pressure in pregnancy or during the first 20 weeks of pregnancy. They also found that there is no relationship between hypertension in pregnancy and smoking as well as obesity.

“We found that mothers who were older when they became pregnant were more likely to have chronic hypertension. Since more women are electing to postpone their first pregnancies, and advanced maternal age is strongly associated with chronic high blood pressure, women should be aware of the risks associated with having high blood pressure during pregnancy,” the lead researcher said.

 “We were a very surprised that the increasing prevalence of obesity and the declining prevalence of smoking rates had virtually no impact on trends in chronic hypertension during pregnancy,” Ananth added.

Pregnancy Longer Pregnancy Can Lead To Stillbirth and Newborn Death. Photo: Pixabay/Bokskapet