title: Association of Fetal Heart Rate Baseline Change and Neonatal Outcomes.
abstract: ObjectiveThe objective of this study was to describe the incidence of baseline change within normal range during labor and its prediction of neonatal outcomes.Materials and MethodsThis was a prospective cohort of singleton, nonanomalous, term neonates with continuous electronic fetal monitoring and normal baseline fetal heart rate throughout the last 2 hours of labor. We determined baseline in 10-minute segments usingEunice Kennedy ShriverNational Institute of Child Health and Human Development criteria. We evaluated baseline changes of ≥ 20 and ≥ 30 bpm for association with acidemia (umbilical cord arterial pH ≤ 7.10) and neonatal intensive care unit (NICU) admission. Finally, we performed a sensitivity analysis of normal neonates, excluding those with acidemia, NICU admission, or 5-minute Apgar < 4.ResultsAmong all neonates (n= 3,021), 1,267 (41.9%) had change ≥ 20 bpm; 272 (9.0%) had ≥ 30 bpm. Among normal neonates (n= 2,939), 1,221 (41.5%) had change ≥20 bpm. Acidemia was not associated with baseline change of any direction or magnitude. NICU admission was associated with decrease ≥ 20 bpm (adjusted odds ratio [aOR]: 2.93; 95% confidence interval [CI]: 1.19 - 7.21) or any direction ≥ 20 bpm (aOR: 4.06; 95% CI: 1.46-11.29). For decrease ≥ 20 bpm, sensitivity and specificity were 40.0 and 81.7%; for any direction ≥ 20 bpm, 75.0 and 58.3%.ConclusionChanges of normal baseline are common in term labor and poorly predict morbidity, regardless of direction or magnitude.
authors.affiliation: Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, Missouri.
authors.forename: Michael
authors.initials: M
authors.lastname: Yang
authors.affiliation: Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, Missouri.
authors.forename: Molly J
authors.initials: MJ
authors.lastname: Stout
authors.affiliation: Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, Missouri.
authors.forename: Julia D
authors.initials: JD
authors.lastname: López
authors.affiliation: Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, Missouri.
authors.forename: Ryan
authors.initials: R
authors.lastname: Colvin
authors.affiliation: Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, Missouri.
authors.forename: George A
authors.initials: GA
authors.lastname: Macones
authors.affiliation: Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, Missouri.
authors.forename: Alison G
authors.initials: AG
authors.lastname: Cahill
mesh_terms: D000138:Acidosis / Q000097:blood*; D000328:Adult; D001034:Apgar Score; D015148:Cardiotocography; D005260:Female; D006340:Heart Rate, Fetal; D006801:Humans; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D007743:Labor, Obstetric; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D012307:Risk Factors; D062606:Tertiary Care Centers; D055815:Young Adult