title: Practice patterns in the timing of antenatal corticosteroids for fetal lung maturity.
abstract: OBJECTIVE
  To determine the practice patterns of antenatal corticosteroid (AS) administration in women with threatened preterm labor.
  
  
  METHODS
  This was a retrospective cohort of patients who received betamethasone between 2009 and 2010, identified through a pharmacy database. Patients with high order multiples; incomplete records and indicated preterm delivery were excluded. Demographic and obstetrical factors were compared between women with an AS to delivery latency of ≤7 days versus >7 days. Parametric and non-parametric tests were used as appropriate. p < 0.05 denotes statistical significance; relative risks with 95% confidence intervals were calculated.
  
  
  RESULTS
  Three-hundred forty-five patients were included. Sixty-eight patients (20%) received AS within 7 days of delivery. Women who received AS ≤7 days before delivery (optimal timing) were more likely to have a transvaginal cervical length ≤2 cm (RR:2.53, CI: 1.2-5.6), cervical dilation ≥2 cm (RR: 3.86, CI: 2.7-5.6) and positive fFN (RR: 2.59, CI: 1.1-6.3). Preterm premature ruptured membranes were also associated with optimal timing of AS (RR: 4.86, CI: 3.4-6.8).
  
  
  CONCLUSIONS
  Eighty percent of patients receive suboptimal timing of AS administration. Factors associated with suboptimal timing are: cervical length >2 cm, cervical dilation <2 cm and negative fFN. Cervical assessment should be a key factor in the decision for AS administration. More research is needed for accurate timing of AS in women with threatened preterm labor.
authors.affiliation: a Department of Obstetrics and Gynecology , Division of Maternal Fetal Medicine, Stony Brook University Hospitals , Stony Brook , NY , USA .
authors.forename: Tracy M
authors.initials: TM
authors.lastname: Adams
authors.forename: Wendy L
authors.initials: WL
authors.lastname: Kinzler
authors.forename: Martin R
authors.initials: MR
authors.lastname: Chavez
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Fazzari
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Vintzileos
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000328:Adult; D001623:Betamethasone / Q000008:administration & dosage; D004334:Drug Administration Schedule; D005260:Female; D005325:Fetal Organ Maturity / Q000187:drug effects; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000187:drug effects / Q000196:embryology*; D007752:Obstetric Labor, Premature / Q000188:drug therapy*; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D011247:Pregnancy; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D001623:Betamethasone
keywords: Antenatal corticosteroids; decision to administer antenatal corticosteroids; timing of antenatal corticosteroids