Related Experiment Video
Updated: Jun 25, 2025

A Rat Model of Mild Intrauterine Hypoperfusion with Microcoil Stenosis
Published on: January 7, 2018
Mean Arterial Pressure and Neonatal Outcomes in Pregnancies Complicated by Mild Chronic Hypertension
Matthew D Moore1, Hui-Chien Kuo, Rachel G Sinkey
1Departments of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, and University of South Alabama at Mobile, Mobile, Alabama, University of North Carolina at Chapel Hill, Chapel Hill, and Duke University, Durham, North Carolina, University of Pennsylvania and Drexel University College of Medicine, Philadelphia, St. Luke's University Health Network, Bethlehem, Magee Women's Hospital and University of Pittsburgh, Pittsburgh, and Lehigh Valley Health Network, Allentown, Pennsylvania, University of Texas at Houston and Baylor College of Medicine and Texas Children's Hospital, Houston, and University of Texas Medical Branch, Galveston, Texas, Columbia University, New York, Winthrop University Hospital, Long Island, and New York Presbyterian Queens Hospital, Flushing, New York, University of Oklahoma, Oklahoma City, Oklahoma, MetroHealth System, Cleveland, The Ohio State University, Columbus, and Wright State University, Fairborn, Ohio, Indiana University, Indianapolis, Indiana, University of Utah Health, Salt Lake City, Utah, Christiana Care Health Services, Newark, Delaware, UnityPoint Health-Meriter Hospital/Marshfield Clinic, Madison, and Medical College of Wisconsin, Milwaukee, Wisconsin, Washington University in St. Louis, St. Louis, Missouri, University of Mississippi Medical Center, Jackson, Mississippi, Yale University, New Haven, Connecticut, University of Colorado, Aurora, and Denver Health Hospital, Denver, Colorado, Emory University, Atlanta, Georgia, University of California, San Francisco, San Francisco, and Stanford University, Stanford, California, Arrowhead Regional Medical Center/Beaumont Hospital, Detroit, Michigan, Virtua Health, Voorhees, New Jersey, Oregon Health & Science University, Portland, Oregon, University of Arkansas for Medical Sciences, Little Rock, Arkansas, University of Tennessee Health Science Center, Memphis, and Vanderbilt University Medical Center, Nashville, Tennessee, Tulane University, New Orleans, Louisiana, University of Kansas Medical Center, Kansas City, Kansas, and Medical University of South Carolina, Charleston, South Carolina; the Center for Women's Reproductive Health, the Department of Biostatistics, and the Division of Neonatology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama; Penn State College of Medicine, Hershey, Pennsylvania; Intermountain Health, Salt Lake City, Utah; Ochsner Baptist Medical Center, New Orleans, Louisiana; St. Peters University Hospital and the Department of Obstetrics, Gynecology and Reproductive Health, New Jersey Medical School, Newark, and the Department of Obstetrics, Gynecology and Reproductive Sciences, Rutgers University-Robert Wood Johnson Medical School, New Brunswick, New Jersey; Weill Cornell University, New York, New York; Zuckerberg San Francisco General Hospital, San Francisco, California; TriHealth, Cincinnati Children's Hospital, Cincinnati, Ohio; the Division of Cardiovascular Sciences, NHLBI, Bethesda, Maryland; and the Department of Women's Health, University of Texas at Austin, Austin, Texas.
Objective:
To estimate the association between mean arterial pressure during pregnancy and neonatal outcomes in participants with chronic hypertension using data from the CHAP (Chronic Hypertension and Pregnancy) trial.
Methods:
A secondary analysis of the CHAP trial, an open-label, multicenter randomized trial of antihypertensive treatment in pregnancy, was conducted. The CHAP trial enrolled participants with mild chronic hypertension (blood pressure [BP] 140-159/90-104 mm Hg) and singleton pregnancies less than 23 weeks of gestation, randomizing them to active treatment (maintained on antihypertensive therapy with a goal BP below 140/90 mm Hg) or standard treatment (control; antihypertensives withheld unless BP reached 160 mm Hg systolic BP or higher or 105 mm Hg diastolic BP or higher). We used logistic regression to measure the strength of association between mean arterial pressure (average and highest across study visits) and to select neonatal outcomes. Unadjusted and adjusted odds ratios (per 1-unit increase in millimeters of mercury) of the primary neonatal composite outcome (bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, or intraventricular hemorrhage grade 3 or 4) and individual secondary outcomes (neonatal intensive care unit admission [NICU], low birth weight [LBW] below 2,500 g, and small for gestational age [SGA]) were calculated.
Results:
A total of 2,284 participants were included: 1,155 active and 1,129 control. Adjusted models controlling for randomization group demonstrated that increasing average mean arterial pressure per millimeter of mercury was associated with an increase in each neonatal outcome examined except NEC, specifically neonatal composite (adjusted odds ratio [aOR] 1.12, 95% CI, 1.09-1.16), NICU admission (aOR 1.07, 95% CI, 1.06-1.08), LBW (aOR 1.12, 95% CI, 1.11-1.14), SGA below the fifth percentile (aOR 1.03, 95% CI, 1.01-1.06), and SGA below the 10th percentile (aOR 1.02, 95% CI, 1.01-1.04). Models using the highest mean arterial pressure as opposed to average mean arterial pressure also demonstrated consistent associations.
Conclusion:
Increasing mean arterial pressure was positively associated with most adverse neonatal outcomes except NEC. Given that the relationship between mean arterial pressure and adverse pregnancy outcomes may not be consistent at all mean arterial pressure levels, future work should attempt to further elucidate whether there is an absolute threshold or relative change in mean arterial pressure at which fetal benefits are optimized along with maternal benefits.
Clinical Trial Registration:
ClinicalTrials.gov , NCT02299414.
Related Concept Videos
Measurement of Blood Pressure
Blood Pressure
Hypertension and Regulation of Blood Pressure
Special considerations while measuring blood pressure
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
Alterations in Blood Pressure
Hypertension (High blood pressure)
Hypertension occurs when blood pressure readings consistently exceed the normal range. It is diagnosed when systolic blood pressure (the top number, indicating pressure while the heart...
Sites for measruring blood pressure
The Brachial Artery: Primary Site for Blood Pressure Measurement

