USA: Study on Elevated Blood Pressure in Pregnancy

A recent study published in Obstetrics & Gynecology has found a progressively higher frequency of adverse cardiometabolic outcomes at 10–14 years after delivery among pregnant women with blood pressure (BP) higher than 120/80 in the early third trimester.

Pregnancy is a transformative time for women, marked by various physiological changes, including alterations in BP. Elevated blood pressure during pregnancy, including conditions like gestational hypertension and preeclampsia, not only poses immediate risks to maternal and fetal health but also has long-term implications for cardiometabolic health.

Against the above background, Christine Field, Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, The Ohio State University, Columbus, OH, and colleagues aimed to investigate the association between elevated BP in the early third trimester and cardiometabolic health 10–14 years after delivery.

For this purpose, the researchers conducted a secondary analysis of the prospective HAPO FUS study. In the early third trimester, blood pressure levels were categorized according to the thresholds established by the American College of Cardiology/American Heart Association. These classifications are as follows:

• Normal BP defined as below 120/80 mm Hg (considered as the reference range)
• Elevated BP falls within the range of 120-129 systolic and below 80 diastolic mm Hg
• Stage 1 hypertension ranges from 130-139 systolic or 80-89 diastolic mm Hg
• Stage 2 hypertension is characterized by 140 mm Hg systolic or higher and 90 mm Hg diastolic or higher

Cardiometabolic outcomes were evaluated 10–14 years post the index pregnancy, focusing on type 2 diabetes mellitus and markers of dyslipidemia. Dyslipidemia measures included:

• LDL cholesterol levels of 130 mg/dL or higher
• Total cholesterol levels of 200 mg/dL or higher
• HDL cholesterol levels of 40 mg/dL or lower
• Triglyceride levels of 200 mg/dL or higher

Adjusted analysis accounted for several covariates: study field center, duration of follow-up, age, body mass index (BMI), height, family history of hypertension and diabetes, smoking and alcohol consumption, parity, and oral glucose tolerance test glucose z score. These factors were considered to account for potential confounding variables and ensure a comprehensive assessment of the long-term health impacts following the initial pregnancy.

Study Findings

• Among 4,692 pregnant individuals at a median gestational age of 27.9 weeks, 8.5% had elevated BP, 14.9% had stage 1 hypertension, and 6.4% had stage 2 hypertension.
• At a median follow-up of 11.6 years, among individuals with elevated BP, there was a higher frequency of diabetes (elevated BP: adjusted relative risk [aRR] 1.88; stage 1 hypertension: aRR 2.58; stage 2 hypertension: aRR 2.83) compared with those with normal BP.
• Among individuals with elevated BP, there was a higher frequency of elevated LDL cholesterol (elevated BP: aRR 1.27; stage 1 hypertension: aRR 1.22, and stage 2 hypertension: aRR 1.38), elevated total cholesterol (elevated BP: aRR 1.27; stage 1 hypertension: aRR 1.16; stage 2 hypertension: aRR 1.41), and elevated triglycerides (elevated BP: aRR 2.24; stage 1 hypertension: aRR 2.15; stage 2 hypertension: aRR 3.24) but not of low HDL cholesterol.

"The frequency of adverse cardiometabolic outcomes at 10–14 years after delivery was progressively higher among pregnant individuals with BP greater than 120/80 mm Hg in the early third trimester," the researchers concluded.

Reference

Field, Christine MD, MPH; Grobman, William A. MD, MBA; Wu, Jiqiang MSc; Kuang, Alan MSc; Scholtens, Denise M. PhD; Lowe, William L. MD; Shah, Nilay S. MD; Khan, Sadiya S. MD, MSc; Venkatesh, Kartik K. MD, PhD. Elevated Blood Pressure in Pregnancy and Long-Term Cardiometabolic Health Outcomes. Obstetrics & Gynecology ():10.1097/AOG.0000000000005674, July 16, 2024. | DOI: 10.1097/AOG.0000000000005674