title: Intracervical sodium nitroprusside versus vaginal misoprostol in first trimester surgical termination of pregnancy: a randomized double-blinded controlled trial.
abstract: BACKGROUND
  Results from small-scale randomized studies on the effectiveness of different preparations of nitric oxide donors in cervical priming before first trimester termination of pregnancies are not consistent. We compared sodium nitroprusside gel to misoprostol, the standard agent for cervical priming in this randomized double-blinded controlled trial.
  
  
  METHODS
  Two hundred pregnant patients between 8 to 12 weeks admitted for surgical termination of pregnancy were recruited. They were randomized into either 400 microg vaginal misoprostol and intracervical placebo gel, or 10 mg intracervical sodium nitroprusside gel and placebo tablets 3 h before the procedure. The baseline cervical dilatation and cumulative force required to dilate the cervix from 4 to 9 mm were measured with a tonometer. Blood pressure was measured and side effects were assessed.
  
  
  RESULTS
  The cumulative force to dilate the cervix from 4 to 9 mm was significantly higher in the sodium nitroprusside group, and the difference remained when a sub-group analysis was performed according to parity. Baseline cervical dilatation, duration of operation and operative blood loss were all in favour of misoprostol. Transient drop in blood pressure was observed after sodium nitroprusside treatment.
  
  
  CONCLUSIONS
  Intracervical sodium nitroprusside is not as effective as misoprostol in cervical priming.
authors.affiliation: Department of Obstetrics & Gynaecology, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China. cwcchan@graduate.hku.hk
authors.forename: C C W
authors.initials: CC
authors.lastname: Chan
authors.forename: O S
authors.initials: OS
authors.lastname: Tang
authors.forename: E H Y
authors.initials: EH
authors.lastname: Ng
authors.forename: C F
authors.initials: CF
authors.lastname: Li
authors.forename: P C
authors.initials: PC
authors.lastname: Ho
mesh_terms: D000020:Abortifacient Agents, Nonsteroidal / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D000028:Abortion, Induced; D000282:Administration, Intravaginal; D000328:Adult; D016063:Blood Loss, Surgical; D001794:Blood Pressure / Q000187:drug effects; D002584:Cervix Uteri; D004106:Dilatation; D004311:Double-Blind Method; D005260:Female; D005782:Gels; D006801:Humans; D016595:Misoprostol / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D009599:Nitroprusside / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D013997:Time Factors
chemical_list: D000020:Abortifacient Agents, Nonsteroidal; D005782:Gels; D016595:Misoprostol; D009599:Nitroprusside