People with no history of high blood pressure may develop first-time hypertension in the weeks and months after childbirth, but there is very little data on first-time hypertension that develops more than six weeks after childbirth.
Summary Background: Postpartum hypertension can be persistent, after a pregnancy complicated by hypertension, or new onset ( de novo ), after a normotensive pregnancy. The objective of this study is to estimate the incidence and identify risk factors for de novo postpartum hypertension (dnPHPTN) among a diverse safety net hospital population. Methods: We conducted a retrospective cohort study of 3925 deliveries from 2016 to 2018. All blood pressure (BP) measurements during pregnancy through 12 months postpartum were extracted from medical records. Patients with chronic hypertension or hypertensive disorders of pregnancy were excluded. dn-PPHTN was defined as 2 separate BP readings with systolic BP ≥140 mm Hg and diastolic BP ≥90 mm Hg at least 48 hours after delivery. Severe dn-PPHTN was defined as systolic BP ≥160 and diastolic BP ≥110. We examined risk factors individually and in combination and the timing of diagnosis. Results: Among the 2465 patients without a history of hypertension, 12.1% (n=298) developed dn-PPHTN; 17.1% of whom had severe dn-PPHTN (n=51). Compared with those without dn-PPHTN; cases were more likely to be ≥35 years old, deliver by cesarean section, or be current or former smokers. Patients with all of these characteristics had a 29% risk of developing dn-PPHTN, which was elevated among non-Hispanic black patients (36%). Approximately 22% of cases were diagnosed after 6 weeks postpartum. Conclusions: More than 1 in 10 patients with normotensive pregnancies experience dn-PPHTN in the year after delivery. Opportunities to monitor and manage patients at highest risk for dn-PPHTN throughout the postpartum year could mitigate cardiovascular-related maternal morbidity. |
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Now, a new study led by a Boston University School of Public Health (BUSPH) researcher found that 1 in 10 women who did not have hypertension before or during pregnancy can develop hypertension up to a year after giving birth. .
Published in Hypertension , a journal of the American Heart Association , the study also found that nearly a quarter of these cases of high blood pressure developed six weeks or more after childbirth, and the mothers most at risk are over 35 years old, current or former smokers or patients who gave birth to their baby by cesarean section.
Postpartum hypertension can lead to complications such as stroke, cardiovascular disease, and kidney failure later in life, but until now, most research has underestimated the burden of new-onset postpartum hypertension. Previous studies on this topic focused primarily on blood pressure measurements taken during childbirth or hospital readmissions. Additionally, standard postpartum care consists of only one clinic visit within four to six weeks after delivery, so new cases of hypertension in the late postpartum period (six weeks to one year after delivery) may go undiagnosed. .
The new study, which included participants of various races and ethnicities, shows that patients with the above three risk factors had a 29% risk of developing new postpartum hypertension, and that this risk increased to 36% among non-black patients. Hispanic.
This information may provide a better understanding of persistent racial disparities in maternal morbidity and mortality in the US and the extent to which hypertension may contribute to these disparities. The findings also underscore the need for strategies to identify and manage postpartum high blood pressure among high-risk patients before they are discharged from the hospital after delivery.
"The study findings have implications for postpartum care, particularly among patients without a history of hypertension," says the study’s lead author, Dr. Samantha Parker (SPH’14), assistant professor of epidemiology at BUSPH and an alumna of the program. PhD in epidemiology from SPH in 2014. .
“We were surprised by the number of cases recorded more than six weeks after delivery, a period that falls outside of routine postpartum follow-up,” says Parker. “Follow-up during this period could mitigate serious postpartum and long-term cardiovascular complications.”
Other studies suggest that the development of hypertension after childbirth may be up to 2.5 times more common among non-Hispanic black women compared to white women, she adds. "Understanding this relationship between pregnancy and hypertension is particularly important to address disparities in maternal cardiovascular disease and death for people of color."
For the study, Parker and colleagues at BUSPH and Boston University Chobanian & Avedisian School of Medicine (Chobanian & Avedisian SOM) used medical records to examine the demographic characteristics and prenatal, delivery, and postpartum data of 3,925 pregnant people. who gave birth between 2016 and 2018. at the Boston Medical Center. The researchers analyzed patients’ blood pressure measurements from the prenatal period to 12 months postpartum, taken in the hospital during office visits, urgent and emergency care, and readmissions.
The team defined new-onset postpartum hypertension as at least two separate blood pressure readings, starting 48 hours after delivery, in which systolic blood pressure was at least 140 mmHg and diastolic blood pressure was at least 90 mmHg. . Severe blood pressure included systolic readings of at least 160 mmHg and diastolic readings of at least 110 mmHg.
Although most patients were diagnosed with postpartum hypertension before being discharged from the hospital after delivery, 43 percent of patients were diagnosed with hypertension for the first time after delivery hospitalization, and about half of These new cases occurred more than six weeks after delivery, emphasizing the need for blood pressure monitoring throughout the postpartum period.
"Future research should explore opportunities to reduce the risk of hypertension in the postpartum period and investigate the implications of postpartum hypertension on future cardiovascular health."
The lead author of the study is Dr. Christina Yarrington, assistant professor of obstetrics and gynecology at Chobanian & Avedisian SOM. Ayodele Ajayi, a research assistant at BUSPH at the time of the study, is a co-author.
