title: Short-term (0-48 h) effects of maternal betamethasone administration on fetal heart rate and its variability.
abstract: The short-term (0-48 h) effects of maternal betamethasone administration on computerized fetal heart rate (FHR) parameters were studied in 36 pregnancies at increased risk for preterm delivery. FHR was recorded for 90 min immediately before the start of betamethasone treatment and again at 6-h intervals during the next 48 h. Multiple linear regression models were used to assess the possible effects on FHR parameters of gestational age, time of day, clinical indication for treatment, and use of tocolytic drugs. Within 12 h after the start of treatment, significant increases occurred in FHR accelerations, and short- and long-term FHR variability (36%, 28%, and 22%, respectively), whereas basal FHR showed a 5% decrease. FHR variability was decreased by 10% at 42-48 h. The observed changes were more pronounced in older (29-33 wk of gestation) compared with younger fetuses (25-28 wk of gestation). Decelerations occurred only in 4 out of 11 compromised fetuses during betamethasone therapy. We conclude that there are significant changes in FHR parameters during the first 48 h after betamethasone administration. These changes are transient in normal fetuses. However, the compromised fetus may be adversely affected by betamethasone.
authors.affiliation: Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Amsterdam, and Department of Perinatology and Gynecology, Wilhelmina Children's Hospital, Utrecht, The Netherlands. S.Lunshof@AMC.UvA.NL
authors.forename: M Simone
authors.initials: MS
authors.lastname: Lunshof
authors.forename: Kees
authors.initials: K
authors.lastname: Boer
authors.forename: Hans
authors.initials: H
authors.lastname: Wolf
authors.forename: Sander
authors.initials: S
authors.lastname: Koppen
authors.forename: Jeanette Klijn
authors.initials: JK
authors.lastname: Velderman
authors.forename: Eduard J H
authors.initials: EJ
authors.lastname: Mulder
mesh_terms: D001623:Betamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005865:Gestational Age; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology*; D006340:Heart Rate, Fetal / Q000187:drug effects*; D006801:Humans; D007231:Infant, Newborn; D008431:Maternal-Fetal Exchange; D007752:Obstetric Labor, Premature; D011247:Pregnancy; D012307:Risk Factors; D013997:Time Factors
chemical_list: D005938:Glucocorticoids; D001623:Betamethasone