Ghanaie 2013.

Methods	A double‐blind, placebo‐controlled RCT.
Participants	Setting: Alzahra educational hospital in Rasht city, Iran. Inclusion criteria Nulliparous women No complications in pregnancy GA > 40 weeks (based on sonography < 20 weeks) Singleton pregnancy Cephalic presentation Bishop score ≥ 4 AFI ≥ 5 Normal FHR Intact membranes Exclusion criteria Having regular contractions (at least 3 x 45 minute contractions in 10 minutes) History of headache IMN intolerance History of cardiopulmonary disease Placenta previa or vaso previa Cord prolapse History of CS or myomectomy Cephalo‐pelvic disproportion (CPD) Cervical cancer Abnormal FHR (tachycardia, bradycardia, deceleration) Twin pregnancy Non‐cephalic presentation Polyhydramnios High blood pressure (≥ 160/110 mg and proteinuria ≥+1) Fetal weight ≥ 3500 g (based on estimated fetal weight (EFW) or sonography) Small mother
Interventions	Intervention (N = 36): 20 mg isosorbide‐5‐mononitrate tablets vaginally twice each 12 h prior to admission for IOL. Women asked to come back urgently to the hospital in case they had leakage, contractions or bleeding. If they had no symptoms they should come back after 12 h. In the next visit, women were asked about the side effects of the tablets including headache and palpitations. If the contraction had not started, another 20 mg of IMN was administered and the patients were asked to come back after 12 h. Immediately after hospitalisation, the Bishop score was assessed and induction with oxytocin was commenced. Control (N = 36): 2 placebo tablets of similar design inserted vaginally twice each 12 h, prior to admission for IOL (according to regimen described above).
Outcomes	Change in Bishop score Mean time to active phase of labour Admission to birth interval Type of birth CS indications (meconium, failure to progress, fetal distress) Min Apgar Headache Palpitation Need for NICU Fetal complications Need for blood transfusion
Notes	Article abstract in English, full article in Iranian. An Iranian‐speaking colleague (E Shakibazadeh) kindly completed data extraction for risk of bias assessment and additional data.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomly allocated to 2 intervention and control groups using random blocks.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding (performance bias and detection bias) Women	Unclear risk	The authors have suggested that their study is a double blind study. However, there is no further information provided.
Blinding (performance bias and detection bias) Clinical staff	Unclear risk	The authors have suggested that their study is a double blind study. However, there is no further information provided.
Blinding (performance bias and detection bias) Outcome assessor	Unclear risk	The authors have suggested that their study is a double blind study. However, there is no further information provided.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Full translation required.
Selective reporting (reporting bias)	Unclear risk	all specified outcomes were reported.
Other bias	Unclear risk	Full translation required.