As per a new study, the number of women diagnosed with high blood pressure during the firsts few weeks of pregnancy has increased drastically in the U.S.
The study included more than 150 million women, between 15 to 49 years, giving birth in different hospitals of the U.S., over a few years. According to the results published in Hypertension, overall there is a 13-fold increase in hypertension rates between 1970 and 2010, predominantly among African American women and older mothers-to-be.
Throughout the study, the researchers demarcated high blood pressure as 140 mm Hg systolic blood pressure (the top number in a blood pressure reading) and 90 mm Hg diastolic blood pressure (the bottom number in a blood pressure reading). However, the American Heart Association defines high blood pressure as 130mm Hg systolic blood pressure and 80 mm Hg diastolic blood pressure.
Cande Ananth, the study's lead author, feels pregnancy later in life can be one of the primary factors causing the increasing rates of hypertension in pregnant women.
Cande V. Ananth, Ph.D., M.P.H., professor and chief of the Division of Epidemiology and Biostatistics in the Obstetrics, Gynecology and Reproductive Sciences Department at Rutgers Robert Wood Johnson Medical School in New Brunswick, New Jersey said, “There was a very, very striking advanced maternal age effect. Women are electing to postpone pregnancy. The mean age at which women become pregnant has increased by four to five years over a four-decade period. And we know that older maternal age is associated with hypertension.”
For better insight, the team also considered the data from the National Hospital Discharge Survey compiled by the U.S. Center for Disease Control and Prevention. They analyzed 151,554,325 delivery-related hospitalizations from 1970 to 2010, and concluded that the factors affecting chronic hypertension were: mother's age, year of delivery, and race.
About 0.63% of the women experienced chronic high blood pressure, with a two-fold higher rate among African American women (1.24%) compared with white women (0.53%). Rates of hypertension showed a sharp increase with advancing maternal age and year of delivery, shooting up from 0.11% in 1970 to 1.52% in 2010, thus causing the 13-fold increase over the past four decades.
On considering the year by year data, they found rates of chronic hypertension increased, on average, by 6 percent per year overall. As compared to African American women (4 percent), white women experienced more substantial yearly increases averaging 7 percent.
Ananth stressed on the importance of a balanced diet during pregnancy. And he urges women to take proper care of their health.
He said, "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."