title: Impact of routine transvaginal ultrasound monitoring of cervical length in twins on administration of antenatal corticosteroids.
abstract: OBJECTIVE
  To evaluate whether routine measurement of cervical length (CL) by transvaginal ultrasound (TVU) in twin pregnancies can enable identification of women who will give birth before 34 weeks and require antenatal corticosteroids (ACSs), and whether it can limit their administration to women who will give birth later.
  
  
  METHODS
  Retrospective comparative study in two tertiary referral centers in France. Women with twin gestations followed in two tertiary university hospital maternity units and who delivered from January 1, 2007 to December 31, 2009 were included. In one center, TVU was targeted to women with cases of suspected preterm labor, while the other center used it monthly for all twin pregnancies. The main outcome measure was the administration of a full course of ACS to twins delivered before 34 weeks.
  
  
  RESULTS
  Two hundred and seventy women were eligible in the "targeted use" group, and 296 women in the "routine use" group. The rate of administration of at least one full course of ACS for twins born before 34 weeks did not differ between the two groups (85.0% in the targeted use group and 90.0% in the routine use group, P=0.40), but the rate of such administration for those born after 34 weeks was lower in the targeted use group (25.7% vs. 81.2%, P<0.01). On adjusting for confounders using logistic regression modeling, no significant difference in ACS administration before 34 weeks was found between the two groups [adjusted odds ratio (aOR), 0.71, 95% confidence interval (CI), 0.39-1.30].
  
  
  CONCLUSIONS
  Routine monitoring performed every month of CL with TVU does not affect the rate of administration of ACS to twins born before 34 weeks, but is associated with a higher rate of such administration for those born later in the specific center of the study.
authors.affiliation: .
authors.forename: Louis
authors.initials: L
authors.lastname: Marcellin
authors.affiliation: .
authors.forename: Marie Victoire
authors.initials: MV
authors.lastname: Senat
authors.affiliation: .
authors.forename: Alexandra
authors.initials: A
authors.lastname: Benachi
authors.affiliation: .
authors.forename: Sophie
authors.initials: S
authors.lastname: Regis
authors.affiliation: .
authors.forename: Dominique
authors.initials: D
authors.lastname: Cabrol
authors.affiliation: .
authors.forename: François
authors.initials: F
authors.lastname: Goffinet
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000328:Adult; D054791:Cervical Length Measurement / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D011247:Pregnancy; D059285:Pregnancy, Twin; D047928:Premature Birth / Q000000981:diagnostic imaging*; D012189:Retrospective Studies
chemical_list: D000305:Adrenal Cortex Hormones
keywords: Corticosteroids; preterm delivery; transvaginal ultrasound; twin gestation