title: Disparity in post-treatment maternal circulating magnesium sulfate levels between twin and singleton gestation: Is this the missing link between plurality and adverse outcome?
abstract: OBJECTIVE
  Magnesium sulfate (MgSO4) administered to women at risk for preterm delivery decreases the risk of cerebral palsy in their children. However, the neuroprotective effect of MgSO4 has not been shown in twin gestations. Thus, the aim of this study was to determine the maternal serum levels of magnesium in twin vs. singleton pregnancies following intravenous treatment of MgSO4.
  
  
  METHODS
  Case control study including two groups of pregnant women who received intravenous MgSO4: (1) twin gestations (n=83) and (2) singleton pregnancies (n=83). Maternal serum magnesium levels 6 and 24 h after initiation of treatment were determined in both groups.
  
  
  RESULTS
  Maternal serum levels of magnesium were significantly lower among patients with twin gestations compared to those with singleton ones 6 h after initiation of treatment (4.6 vs. 4.8 mg/dL, P=0.003). In addition, the rate of pregnant women who obtained therapeutic levels 6 h after initiation of treatment was significantly lower in twin gestations than in singleton ones (36% vs. 58%, P=0.008). Multiple regression analysis revealed that twin gestations were independently and significantly associated with low maternal serum magnesium levels.
  
  
  CONCLUSIONS
  Maternal serum concentrations of magnesium are lower in twin pregnancies than in singleton ones following MgSO4 treatment, which might explain the decreased neuroprotective effect of MgSO4 reported in twin pregnancies.
authors.forename: Lilach
authors.initials: L
authors.lastname: Marom-Haham
authors.forename: Shali
authors.initials: S
authors.lastname: Mazaki-Tovi
authors.forename: Itamar
authors.initials: I
authors.lastname: Zilberman
authors.forename: Anat
authors.initials: A
authors.lastname: Kalter
authors.forename: Jigal
authors.initials: J
authors.lastname: Haas
authors.forename: Eyal
authors.initials: E
authors.lastname: Sivan
authors.forename: Eyal
authors.initials: E
authors.lastname: Schiff
authors.forename: Yoav
authors.initials: Y
authors.lastname: Yinon
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002547:Cerebral Palsy / Q000097:blood / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007262:Infusions, Intravenous; D008274:Magnesium / Q000097:blood*; D008275:Magnesium Deficiency / Q000097:blood / Q000150:complications; D008278:Magnesium Sulfate / Q000008:administration & dosage*; D018696:Neuroprotective Agents / Q000008:administration & dosage; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin / Q000097:blood*; D047928:Premature Birth / Q000097:blood* / Q000209:etiology / Q000517:prevention & control*; D012044:Regression Analysis
chemical_list: D018696:Neuroprotective Agents; D008278:Magnesium Sulfate; D008274:Magnesium