title: 48-hours administration of fenoterol in spontaneous preterm labor - does it affect fetal preload?
abstract: OBJECTIVE
  to investigate whether any changes in the preload index (PLI) occur within the first 48 hours of fenoterol intravenous tocolysis.
  
  
  METHODS
  Doppler evaluation of placental and fetal circulation was performed in 36 pregnant women prior to fenoterol administration and after 24/48 hours. Measurements were obtained from a longitudinal section of the inferior vena cava (IVC) and preload index was calculated. To determine changes over time, an all study variable analysis of variance (ANOVA) for repeated measurements, followed by Tukey-Kramer's multiple comparison test was used. The effects of additional clinical covariates were checked.
  
  
  RESULTS
  The maternal heart rate values were significantly increased after 24 hours and 48 hours in comparison to pre-treatment values. No significant changes in fetal heart rate were observed during treatment. The fetal IVC PLI values were significantly reduced after 24 hours and 48 hours of treatment. The increase in PLI values when comparing 24 and 48 hours results were not statistically significant. These observations were consistent with ANOVA post-hoc analysis.
  
  
  CONCLUSIONS
  48 hours intravenous administration of fenoterol appears not to alter inferior vena cava blood flow by itself. The reduction in PLI values may reflect lower fetal preload conditions during the course of successful tocolytic treatment. Therefore, Doppler IVC PLI measurement should be considered as a possible additional assessment method of effectiveness of treatment. However, other Doppler venous blood flow parameters should be assessed to confirm the results and clarify whether maternal corticosteroids administration may be interfering with the results.
authors.affiliation: Department of Feto-Maternal Medicine and Gynecology, "Polish Mother" Memorial Research Institute, Lodz, Poland. mariusz.grzesiak@gmail.com.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Grzesiak
authors.affiliation: Department of Radiology, "Polish Mother" Memorial Research Institute, Lodz, Poland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Forys
authors.affiliation: Outpatient Department of Obstetrics and Gynecology, "Polish Mother" Memorial Research Institute, Lodz, Poland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Sobczak
authors.affiliation: Division of English Studies, The Medical University of Lodz, Poland.
authors.forename: Rehana B
authors.initials: RB
authors.lastname: Ahmed
authors.affiliation: Department of Feto-Maternal Medicine and Gynecology, "Polish Mother" Memorial Research Institute, Lodz, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Wilczynski
mesh_terms: D000328:Adult; D005260:Female; D005280:Fenoterol / Q000008:administration & dosage*; D005333:Fetus / Q000098:blood supply* / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006340:Heart Rate, Fetal / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D007752:Obstetric Labor, Premature / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D011247:Pregnancy; D015149:Tocolytic Agents / Q000008:administration & dosage*; D016216:Ultrasonography, Prenatal; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology; D055815:Young Adult
chemical_list: D015149:Tocolytic Agents; D005280:Fenoterol