Condition category
Pregnancy and Childbirth
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Fasting (not eating or drinking) before surgery is essential if a patient is going to receive a general anaesthetic (be put to sleep) for surgery. This is because when a person is anaesthetised, the body’s natural reflexes stop. If the stomach has food or drink in it, there is a risk that it may be brought up and inhaled into the lungs (aspiration), which can affect breathing as well as cause damage to the lungs. As a rule, patients need to fast for a minimum of six hours after having a light meal (e.g. tea and toast), for two hours after having clear fluids, and for eight hours after a full meal. Pregnant women have a higher risk of aspiration because of the various changes that happen to the body during pregnancy. The aim of this study is to find out whether six hours fasting time is enough for heavily pregnant women to have an empty stomach.

Who can participate?
Adult women who are at least 36 weeks pregnant with a single baby.

What does the study involve?
Participants receive a phone call a day or two before their first antenatal (pregnancy) visit after 36 weeks at the hospital advising them not to eat or drink anything for 6 hours after having a light meal before the appointment. At the appointment, participants have their stomach scanned with an ultrasound probe in order to see how much is in their stomach. After the scan, participants are allowed to eat and drink as normal.

What are the possible benefits and risks of participating?
There are no direct benefits or risks involves with participating in this study.

Where is the study run from?
The National Maternity Hospital (Ireland)

When is the study starting and how long is it expected to run for?
August 2016 to December 2016

Who is funding the study?
The National Maternity Hospital (Ireland)

Who is the main contact?
Dr Sheeba Hakak

Trial website

Contact information



Primary contact

Dr Sheeba Hakak


Contact details

Department of Anaesthesia
The National Maternity Hospital
2 Hollis Street
Dublin 2
+353 1 6373100

Additional identifiers

EudraCT number number

Protocol/serial number

EC 22-2016

Study information

Scientific title

Is six hours’ fasting time enough in term pregnancy ? A prospective observational cohort study using ultrasound to determine the residual gastric volume in fasted pregnant patients of ≥36 weeks gestation


Study hypothesis

The aim of the study is to determine whether six hours fasting time is enough in term pregnancy by performing ultrasound of the stomach after six hours of fasting.

Ethics approval

HSE Research Ethics Committee (National Maternity Hospital, Dublin), 06/09/2016.

Study design

Prospective observational cohort study

Primary study design


Secondary study design

Cohort study

Trial setting


Trial type


Patient information sheet

See additional files


Anaesthesia during pregnancy


Participating patients are contacted lead investigator a day or two before their regular antenatal appointment and given instructions what time to start their fast, and what to eat just before starting fasting (i.e. tea and toast). They will also be informed the location of the scan.

On the day of the appointment, the lead investigator will meet the patients and confirm the fasting times and carry out a gastric ultrasound in the supine position first followed by right lateral decubitus position (RLD) at their antenatal appointment after having fasted for six hours.

Patients charts will be reviewed by the lead investigator to obtain the necessary information like weight, height, and BMI.

Intervention type



Drug names

Primary outcome measure

Percentage of patients who have a critical residual gastric volume after six hours of fasting is determined
by assessing gastric volumes in ml/kg using gastric ultrasound at the study visit.

Secondary outcome measures

No secondary outcome measures

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Aged 18 years and over
2. Singleton pregnancy with a gestational age of 36 weeks or above
3. Ability to understand study protocol and provide informed consent

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Patient refusal to participate
2. Comorbidities affecting gastrointestinal motility, such as diabetes or preecclampsia
3. Previous gastric surgeries,hiatus hernia
4. BMI >35
5. Oligo or polyhydramnios on most recent scan
6. Severe intrauterine growth retardation

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

The National Maternity Hospital
2 Holles street
Dublin 2

Sponsor information


The National Maternity Hospital

Sponsor details

2 Hollis Street
Dublin 2

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

The National Maternity Hospital

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer reviewed journal.

Intention to publish date


Participant level data

Not expected to be available

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

15/09/2016: Participant information sheet uploaded.