Mean Arterial Pressure Linked to Neonatal Outcomes in Pregnancies with Mild Chronic Hypertension: Study

"Given that the relationship between MAP and adverse pregnancy outcomes may not be consistent at all mean arterial pressure levels, future work should determine whether there is an absolute threshold or relative change in MAP at which fetal benefits are optimized along with maternal benefits," the researchers wrote.

Matthew D. Moore, University of Alabama at Birmingham, Birmingham, AL, and colleagues aimed 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.

For this purpose, they conducted a secondary analysis of the CHAP trial, an open-label, multicenter randomized trial of antihypertensive treatment in pregnancy. 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. They were randomized 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).

Logistic regression measured the strength of association between MAP (average and highest across study visits) and selected neonatal outcomes. They calculated adjusted and unadjusted (per 1-unit rise in millimeters of mercury) of the primary neonatal composite outcome (retinopathy of prematurity, bronchopulmonary dysplasia, intraventricular hemorrhage grade 3 or 4, or necrotizing enterocolitis) and individual secondary outcomes (low birth weight [LBW] below 2,500 g, neonatal intensive care unit admission [NICU], and small for gestational age [SGA]).

The study revealed the following findings:

· 2,284 participants were included: 1,155 active and 1,129 control.

· Adjusted models controlling for randomization group showed 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), LBW (aOR 1.12), NICU admission (aOR 1.07), SGA below the fifth percentile (aOR 1.03), and SGA below the 10th percentile (aOR 1.02).

· Models using the highest mean arterial pressure than average mean arterial pressure also demonstrated consistent associations.

The study highlights the need for individualized management strategies in pregnancies complicated by mild chronic hypertension, with a focus on optimizing maternal blood pressure control to enhance neonatal health.

Reference:

Moore, Matthew D. DrPH, MPH; Kuo, Hui-Chien MS; Sinkey, Rachel G. MD; Boggess, Kim MD; Dugoff, Lorraine MD; Sibai, Baha MD; Lawrence, Kirsten MD, MSCE; Hughes, Brenna L. MD, MSc; Bell, Joseph MD; Aagaard, Kjersti MD, PhD; Edwards, Rodney K. MD, MS; Gibson, Kelly S. MD; Haas, David M. MD; Plante, Lauren MD; Metz, Torri D. MD, MS; Casey, Brian MD; Esplin, Sean MD; Longo, Sherri MD; Hoffman, Matthew K. MD, MPH; Saade, George R. MD; Hoppe, Kara K. DO, MS; Foroutan, Janelle MD; Tuuli, Methodius MD; Owens, Michelle Y. MD; Simhan, Hyagriv N. MD, MS; Frey, Heather A. MD; Rosen, Todd MD; Palatnik, Anna MD; Baker, Susan MD; August, Phyllis MD, MPH; Reddy, Uma M. MD; Kinzler, Wendy MD; Su, Emily J. MD; Krishna, Iris MD; Nguyen, Nguyet A. MD; Norton, Mary E. MD; Skupski, Daniel MD; El-Sayed, Yasser Y. MD; Ogunyemi, Dotun MD; Librizzi, Ronald DO; Pereira, Leonardo MD; Magann, Everett F. MD; Habli, Mounira MD; Williams, Shauna MD; Mari, Giancarlo MD; Pridjian, Gabriella MD, MBA; McKenna, David S. MD; Parrish, Marc DO; Chang, Eugene MD; Osmundson, Sarah MD, MS; Quiñones, Joanne N. MD, MSCE; Leach, Justin PhD; Sanusi, Ayodeji MD; Galis, Zorina S. PhD; Harper, Lorie MD, MSCI; Ambalavanan, Namasivayam MD; Szychowski, Jeff M. PhD; Tita, Alan T.N. MD, PhD. Mean Arterial Pressure and Neonatal Outcomes in Pregnancies Complicated by Mild Chronic Hypertension. Obstetrics & Gynecology ():10.1097/AOG.0000000000005611, May 23, 2024. | DOI: 10.1097/AOG.0000000000005611