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Optimal Timing of Delivery for Pregnant Individuals With Mild Chronic Hypertension
Torri D Metz1, Hui-Chien Kuo, Lorie Harper
1Departments of Obstetrics and Gynecology, University of Utah, Salt Lake City, Utah, University of Texas at Houston, Houston, and University of Texas Medical Branch, Galveston, Texas, University of Pennsylvania and Drexel University College of Medicine, Philadelphia, and Magee Women's Hospital and University of Pittsburgh, Pittsburgh, Pennsylvania, University of North Carolina at Chapel Hill, Chapel Hill, and Duke University, Durham, North Carolina, Columbia University and Weill Cornell University, New York, and NYU Langone Hospital-Long Island, Long Island, and NewYork-Presbyterian Queens Hospital, Flushing, New York, University of Oklahoma Health Sciences, Oklahoma City, Oklahoma, Indiana University, Indianapolis, Indiana, University of Alabama at Birmingham, Birmingham, and University of South Alabama at Mobile, Mobile, Alabama, UnityPoint Health-Meriter Hospital/Marshfield Clinic, Madison, and Medical College of Wisconsin, Milwaukee, Wisconsin, Washington University, St. Louis, Missouri, University of Mississippi Medical Center, Jackson, Mississippi, The Ohio State University, Columbus, and Wright State University and Miami Valley Hospital, Dayton, Ohio, Rutgers University-Robert Wood Johnson Medical School, New Brunswick, New Jersey, Yale University, New Haven, Connecticut, University of Colorado, Aurora, and Denver Health, Denver, Colorado, Emory University, Atlanta, Georgia, University of California, San Francisco, San Francisco, Stanford University, Stanford, and Arrowhead Regional Medical Center, Colton, California, Beaumont Hospital, Michigan, Grosse Pointe, Michigan, Oregon Health & Science University, Portland, Oregon, Tulane University, New Orleans, Louisiana, and University of Kansas Medical Center, Kansas City, Kansas; the Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Baylor College of Medicine and Texas Children's Hospital, Houston, and the Department of Women's Health, University of Texas at Austin, Austin, Texas; the Department of Biostatistics, the Division of Neonatology, Department of Pediatrics, and the Center for Women's Reproductive Health, University of Alabama at Birmingham, Birmingham, Alabama; Ochsner Baptist Medical Center, New Orleans, Louisiana; St. Luke's University Health Network, Fountain Hill, and the Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Lehigh Valley Health Network, Allentown, Pennsylvania; MetroHealth System, Cleveland, and the Fetal Care Center of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Intermountain Healthcare, Ogden, Utah; Christiana Care Health Services, Newark, Delaware; St. Peters University Hospital, New Brunswick, Virtua Health, Marlton, and the Department of Obstetrics, Gynecology and Women's Health, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey; Zuckerberg San Francisco General Hospital, San Francisco, California; the Department of Obstetrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas; Obstetrics and Gynecology/Maternal-Fetal Medicine, University of Tennessee Health Science Center, Memphis, Tennessee; Medical University of South Carolina, Charleston, South Carolina; and the Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, Bethesda, Maryland.
Objective:
To investigate the optimal gestational age to deliver pregnant people with chronic hypertension to improve perinatal outcomes.
Methods:
We conducted a planned secondary analysis of a randomized controlled trial of chronic hypertension treatment to different blood pressure goals. Participants with term, singleton gestations were included. Those with fetal anomalies and those with a diagnosis of preeclampsia before 37 weeks of gestation were excluded. The primary maternal composite outcome included death, serious morbidity (heart failure, stroke, encephalopathy, myocardial infarction, pulmonary edema, intensive care unit admission, intubation, renal failure), preeclampsia with severe features, hemorrhage requiring blood transfusion, or abruption. The primary neonatal outcome included fetal or neonatal death, respiratory support beyond oxygen mask, Apgar score less than 3 at 5 minutes, neonatal seizures, or suspected sepsis. Secondary outcomes included intrapartum cesarean birth, length of stay, neonatal intensive care unit admission, respiratory distress syndrome (RDS), transient tachypnea of the newborn, and hypoglycemia. Those with a planned delivery were compared with those expectantly managed at each gestational week. Adjusted odds ratios (aORs) with 95% CIs are reported.
Results:
We included 1,417 participants with mild chronic hypertension; 305 (21.5%) with a new diagnosis in pregnancy and 1,112 (78.5%) with known preexisting hypertension. Groups differed by body mass index (BMI) and preexisting diabetes. In adjusted models, there was no association between planned delivery and the primary maternal or neonatal composite outcome in any gestational age week compared with expectant management. Planned delivery at 37 weeks of gestation was associated with RDS (7.9% vs 3.0%, aOR 2.70, 95% CI, 1.40-5.22), and planned delivery at 37 and 38 weeks was associated with neonatal hypoglycemia (19.4% vs 10.7%, aOR 1.97, 95% CI, 1.27-3.08 in week 37; 14.4% vs 7.7%, aOR 1.82, 95% CI, 1.06-3.10 in week 38).
Conclusion:
Planned delivery in the early-term period compared with expectant management was not associated with a reduction in adverse maternal outcomes. However, it was associated with increased odds of some neonatal complications. Delivery timing for individuals with mild chronic hypertension should weigh maternal and neonatal outcomes in each gestational week but may be optimized by delivery at 39 weeks.
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