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Intravenous (IV) Nitroglycerin for Versions in Nulliparous Women (INVERT (01))

This study has been completed.
Information provided by:
University of Calgary Identifier:
First received: May 8, 2009
Last updated: August 27, 2013
Last verified: August 2013

Breech presentations (where a baby presents with feet or bottom down) have an increased risk of perinatal and neonatal complications, and are usually delivered by cesarean section. As an alternative, so that the baby can be delivered vaginally, an attempt can be made to turn the baby so that it is head down: this manoeuvre is called an external cephalic version (ECV).

Drugs that relax the uterus (tocolytic agents) are sometimes used to help improve ECV success rates. Nitroglycerin is a tocolytic agent, but intravenous nitroglycerin has not been tested as an agent to help ECV. There is some suggestion that nitroglycerin may be more helpful in women who have not previously been pregnant (nulliparous women) than in women who have been pregnant more than once (multiparous women), and so we have planned two trials.

This study is designed to answer the following questions for nulliparous women:

Will administration of IV nitroglycerin for uterine relaxation improve ECV success rates? Will an increase in ECV success result in a decreased cesarean section rate?

Condition Intervention
Breech Presentation
Complication of Pregnancy
Drug: IV Nitroglycerin
Drug: Normal saline

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: INVERT: IV Nitroglycerin for Versions Trial - a Randomized Placebo-controlled Trial in Nulliparous Women

Resource links provided by NLM:

Further study details as provided by University of Calgary:

Primary Outcome Measures:
  • Success of ECV (ie fetus turned from Breech to cephalic) at the end of ECV procedure [ Time Frame: Recorded at finish of ECV attempt ]

Secondary Outcome Measures:
  • Success of ECV (ie fetus in cephalic presentation) at time of delivery [ Time Frame: Recorded at time of birth ]
  • Mode of delivery [ Time Frame: Recorded at time of birth ]
  • Maternal side effects and adverse events [ Time Frame: Recorded until date of birth (up to 3 weeks following ECV) ]

Enrollment: 82
Study Start Date: March 2003
Study Completion Date: February 2008
Primary Completion Date: October 2006 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: 1
Treatment solution consisted of 100 micrograms/mL of nitroglycerin. After an initial 1ml dose, further doses could be given in 1-3mL increments until uterine relaxation was achieved, or up to a recommended maximum of 10mL
Drug: IV Nitroglycerin
IV injection, initial dose of 1ml, with further doses of 1-3mL, up to a recommended maximum of 10mL
Placebo Comparator: 2
Placebo solution was saline. After an initial 1ml dose, further doses could be given in 1-3mL increments until uterine relaxation was achieved, or up to a recommended maximum of 10mL
Drug: Normal saline
IV injection, initial dose of 1ml, with further doses of 1-3mL, up to a recommended maximum of 10mL


Ages Eligible for Study:   Child, Adult, Senior
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • any non-cephalic presentation
  • singleton pregnancy
  • >/= 37 weeks gestational age
  • normal amniotic fluid volume
  • reassuring fetal heart rate

Exclusion Criteria:

  • labor
  • ruptured membranes
  • history of third trimester bleeding
  • any pre-existing uterine scar
  • pregnancy induced hypertension and gestational diabetes
  • oligohydramnios and polyhydramnios
  • intrauterine growth restriction or macrosomia
  • hypotension or any serious medical illness
  • inability to comprehend the consent form
  Contacts and Locations
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Please refer to this study by its identifier: NCT00896311

Canada, Alberta
Foothills Medical Centre
Calgary, Alberta, Canada, T2N 4J8
Peter Lougheed Centre
Calgary, Alberta, Canada
Rockyview Hospital
Calgary, Alberta, Canada
Sponsors and Collaborators
University of Calgary
Principal Investigator: Bruce B Allan, MD PhD Calgary Health Region
  More Information

Responsible Party: Dr Bruce Allan, Department of Obstetrics & Gynecology, Calgary Health Region Identifier: NCT00896311     History of Changes
Other Study ID Numbers: INVERT-01
Study First Received: May 8, 2009
Last Updated: August 27, 2013

Additional relevant MeSH terms:
Breech Presentation
Pregnancy Complications
Obstetric Labor Complications
Vasodilator Agents processed this record on May 23, 2017