October 13 (News) – Women who give birth prematurely are about twice as likely to develop high blood pressure later in life than those who give birth to their babies to full birth, according to a study published Wednesday by JAMA Network Open.
In a study of 2 million women in Sweden, the data showed that those who had babies less than 37 weeks of gestation – 39 to 41 weeks of gestation are considered full term – were 67% more likely to develop high blood pressure over the next decade.
Women with births that occur after 22 to 27 weeks of gestation – which are considered “extremely early” – had a two-fold higher risk of hypertension over the next 10 years compared to those who gave birth to full birth, the researchers said.
According to the researchers, the risk was 55% higher in women who gave birth after 28 to 33 weeks.
Although the increased risk of hypertension in women with a history of preterm birth decreased after the first decade, it remained higher compared to those who had no preterm birth for up to 40 years, they said.
This applies even to women who have no family history of high blood pressure, which puts them at increased risk for the condition, the researchers said.
“A shorter gestation period was associated with a significantly higher future risk of chronic high blood pressure,” write researchers from the Icahn School of Medicine on Mount Sinai in New York City.
This applies “even after adjustment to preeclampsia” – or high blood pressure during pregnancy – and “other hypertensive pregnancy disorders,” they said.
About one in 10 babies in the United States will be born prematurely or in less than 39 weeks of gestation, according to the Centers for Disease Control and Prevention.
Fewer than 1 in 15 pregnant women develop high blood pressure or hypertension during pregnancy, which increases their risk of premature birth, the agency estimates.
However, less is known about the risk of high blood pressure after pregnancy in women with premature births, according to Mount Sinai researchers.
For this study, the researchers, in collaboration with colleagues from Lund University in Malmö, Sweden, analyzed data from nearly 2.2 million Swedish women who together gave birth to more than 4.3 million children between 1973 and 2016.
More than 350,000 of the women enrolled in the study developed chronic high blood pressure, the researchers said.
Women in the study with a history of preterm births were 25% more likely to have chronic high blood pressure during childbirth than those with full-time births, with the risk being highest in the first 10 years, the data showed.
“Premature birth should now be recognized as a risk factor for high blood pressure throughout life,” the researchers write.
“Women with a history of premature birth need early preventive assessment and long-term risk reduction and monitoring for high blood pressure,” they said.