Skip to main content
  1. Right Decisions
  2. GGC - Clinical Guidelines
  3. Maternity
  4. Back
  5. Allergy, anaphylaxis and critical care (Maternity)
  6. GTN Nitroglycerin for Emergency Cervico-Uterine Relaxation (492)
Please update your RDS mobile app to version 4.7.1

We are pleased to advise that deep linking capability, enabling users to directly download individual mobile toolkits, has now been released on the RDS mobile app. When you install the update, you will see that each toolkit has a small QR code icon the header area beside the search icon – see screenshot below. Clicking on this icon will open up a window with a full-size QR code and the alternative of a short URL for sharing with users. Instructions are provided.

You may need to actively install the update to install RDS app version 4.7.1 to see this improvement. Installing this update is also strongly recommended to get the full benefits of the new contingency arrangements – specifically, that if the RDS website should fail, you will still be able to download new mobile app toolkits. 

To check your current RDS version, click on the three dots bottom right of the RDS app screen. This takes you to a “More” page where you will see the version number.  To install latest updates:

On iPhones – go to the Apple store, click on your profile icon top right, scroll down to see the apps waiting to be updated and update the RDS app.

On Android phones – these can vary, but try going to the Google Play store, click on your profile icon top right, click on “Manage apps and device”, select and update the RDS app.

Please get in touch with ann.wales3@nhs.scot with any questions.

GTN Nitroglycerin for Emergency Cervico-Uterine Relaxation (492)

Please report any inaccuracies or issues with this guideline using our online form

Rapid and transient relaxation of the cervix and uterus is occasionally required to allow obstetric manoeuvres during emergencies.

A number of case reports and trials have shown nitroglycerin (Glyceryl Trinitrate) to provide rapid and transient cervico-uterine relaxation (albeit unlicensed).

The therapeutic effect is seen within 1-2 minutes of administration and lasts for 3-5 minutes.

Indications:

  • Fetal head entrapment during vaginal breech delivery.
  • When uterine relaxation is required during a difficult caesarean section.
  • Management of uterine inversion

Administration

Maternal IV cannula requires to be sited prior to administration of GTN (the drug may cause profound drop in BP)

Sublingual via metered pump:

Nitrolingual pump spray should be primed before using it by pressing the nozzle once.

1-2 sprays (400-800 micrograms) administered as spray droplets beneath the tongue (do not inhale). Ask woman to close her mouth after spray administered.

Repeat after 5 minutes if hypertonus sustained.

Cautions

  • Nitrates may increase intraocular pressure and so should be used with caution in glaucoma.

Contraindications

  • Uncorrected hypovolaemia
  • Severe anaemia (Hb<60 g/L)
  • Increased intracranial pressure
  • Constrictive pericarditis / pericardial tamponade
  • Hypersensitivity to GTN. Nitrates, coconut oil, ethanol, glycerol monocaprylocaproate, peppermint oil

Side-effects

Due to vasodilating effects –

Headache
Hypotension
Reflex tachycardia or bradycardia 
Rarely nausea, vomiting,flushing

(For complete list cautions,contraindications and side-effects see BNF)

Additional information

Haemodynamic monitoring, a rapidly running I.V. infusion and immediately available ephedrine and phenylephidrine are mandatory prior to the use of Nitroglycerin (Glyceryl Trinitrate).

Once the third stage is complete, a Syntocinon infusion should be commenced. 

Editorial Information

Last reviewed: 24/11/2021

Next review date: 29/11/2026

Author(s): Julie Murphy.

Version: 4

Approved By: Obstetric Clinical Guideline Group

Document Id: 492

References

Smith GN & Brien JF. Use of nitroglycerin for uterine relaxation. Obstet Gynecol Survey 1998; 53:9:559-65.

Oxford Handbook Anaesthesia 2016