title: The NIFTY study: a multicentre randomised double-blind placebo-controlled trial of nifedipine maintenance tocolysis in fetal fibronectin-positive women in threatened preterm labour.
abstract: OBJECTIVE
  In an unselected group of women with signs of preterm labour, maintenance tocolysis is not effective in the prevention of preterm birth and does not improve neonatal outcome. Among women with signs of preterm labour, those who are fetal fibronectin positive have an increased risk of preterm birth. We investigated whether maintenance tocolysis with nifedipine would delay delivery and improve neonatal outcome in women with threatened preterm labour and a positive fetal fibronectin status.
  
  
  METHODS
  Women with a singleton pregnancy in threatened preterm labour (24(+0) to 33(+6)  weeks) with a positive fetal fibronectin test were randomised to nifedipine or placebo. Study medication was continued until 36 completed weeks' gestation. The primary endpoint was prolongation of pregnancy of seven days. Secondary endpoints were gestational age at delivery and length of NICU admission.
  
  
  RESULTS
  Of the 60 participants, 29 received nifedipine and 31 placebo. Prolongation of pregnancy by >7 days occurred in 22/29 (76%) in the nifedipine group and 25/31 (81%) in the placebo group (relative risks, RR 0.94 [0.72-1.2]). Gestational age at delivery was 36.1 ± 5.1 weeks for nifedipine and 36.8 ± 3.6 weeks for placebo (P = 0.027). Length of NICU admission [median (interquartile ranges, IQR)] was 27 (24-41) days and 16 (8-37) days in nifedipine and placebo groups, respectively (P = 0.17).
  
  
  CONCLUSIONS
  In women with threatened preterm labour who are fetal fibronectin positive, maintenance tocolysis with nifedipine does not seem to prolong pregnancy, nor reduce length of NICU admission.
authors: Maternal-Fetal Medicine, Auckland District Health Board, Auckland, New Zealand.
authors: Emma
authors: E
authors: Parry
authors: Carolien
authors: C
authors: Roos
authors: Peter
authors: P
authors: Stone
authors: Lynsey
authors: L
authors: Hayward
authors: Ben Willem
authors: BW
authors: Mol
authors: Lesley
authors: L
authors: McCowan
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D005260:Female; D005353:Fibronectins / Q000097:blood; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D053208:Kaplan-Meier Estimate; D009543:Nifedipine / Q000627:therapeutic use*; D007752:Obstetric Labor, Premature / Q000188:drug therapy*; D054238:Perinatal Mortality; D011247:Pregnancy; D047928:Premature Birth / Q000517:prevention & control; D015145:Tocolysis; D015149:Tocolytic Agents / Q000627:therapeutic use*; D017211:Treatment Failure
chemical_list: D005353:Fibronectins; D015149:Tocolytic Agents; D009543:Nifedipine
keywords: maintenance tocolysis; nifedipine; preterm labour