title: Effect of magnesium sulphate on fetal heart rate parameters: a systematic review.
abstract: OBJECTIVE
  To examine the potential effects of intravenous magnesium sulphate (MgSO4) administration on antepartum and intrapartum fetal heart rate (FHR) parameters measured by cardiotocography (CTG) or electronic fetal monitoring (EFM).
  
  
  METHODS
  We undertook a systematic review of randomized controlled trials, observational studies, and case series. Studies were reviewed independently by two reviewers and qualitatively analyzed with regard to CTG/EFM parameters (baseline FHR, variability and acceleration-deceleration patterns), types of participants, interventions offered, and outcomes reported.
  
  
  RESULTS
  Of 18 included studies, two were RCTs (72 women); 12 were prospective observational studies (269 women), 10 of which were of a pre- and post-intervention design; one was a prospective cohort study (36 women) and three were retrospective cohort studies (555 women). Lower baseline FHR was associated with MgSO4 exposure in seven of nine relevant studies. Decreased FHR variability was reported in nine of 12 relevant studies. Reductions in reactivity or acceleration pattern were seen in four of six relevant studies without an increase in decelerative patterns. All changes were small and not associated with adverse clinical outcomes.
  
  
  CONCLUSIONS
  Maternal administration of MgSO4 for eclampsia prophylaxis/treatment, tocolysis or fetal neuroprotection appears to have a small negative effect on FHR, variability, and accelerative pattern, but is not sufficient clinically to warrant medical intervention.
authors: Department of Obstetrics and Gynaecology, McMaster University, Hamilton ON; Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver BC.
authors: Alysha
authors: A
authors: Nensi
authors: Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver BC; Child and Family Research Institute, University of British Columbia, Vancouver BC.
authors: Dane A
authors: DA
authors: De Silva
authors: Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver BC; Child and Family Research Institute, University of British Columbia, Vancouver BC.
authors: Peter
authors: P
authors: von Dadelszen
authors: Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver BC.
authors: Diane
authors: D
authors: Sawchuck
authors: Child and Family Research Institute, University of British Columbia, Vancouver BC; Department of Paediatrics, University of British Columbia, Vancouver BC; Division of Neonatology, British Columbia Women's Hospital and Health Centre, Vancouver BC.
authors: Anne R
authors: AR
authors: Synnes
authors: Department of Obstetrics and Gynaecology, Eastern Health, Memorial University of Newfoundland, St. John's NL.
authors: Joan
authors: J
authors: Crane
authors: Child and Family Research Institute, University of British Columbia, Vancouver BC; Department of Medicine, University of British Columbia, Vancouver BC; Department of Medicine, British Columbia Women's Hospital and Health Centre, Vancouver BC.
authors: Laura A
authors: LA
authors: Magee
mesh_terms: D000927:Anticonvulsants / Q000009:adverse effects*; D015148:Cardiotocography; D005260:Female; D006340:Heart Rate, Fetal / Q000187:drug effects*; D006801:Humans; D008278:Magnesium Sulfate / Q000009:adverse effects*; D011247:Pregnancy
chemical_list: D000927:Anticonvulsants; D008278:Magnesium Sulfate
keywords: cardiotocograph; fetal heart rate; magnesium sulphate; non-stress test