Condition category
Urological and Genital Diseases
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
In vitro fertilisation (IVF) is a technique that is used to help people with fertility problems to have a baby. During IVF, an egg is taken from the woman's ovaries and fertilised with sperm in a laboratory. The fertilised egg (embryo) is then returned to the woman's uterus (womb). Current embryo transfer techniques have remained largely unchanged since IVF treatment began. Traditionally there have been two techniques: a “clinical touch” method used to guide the transfer catheter (tube) to within 10mm of the uterine fundus (top of the uterus) before injection of the embryo. This is essentially a “blind” procedure and works on tactile sensation (touch). Similarly some clinicians transfer the embryos at a fixed distance from the external cervical opening (about 6cm), but this works on the assumption that the uterine dimensions including the cervix are the same for all women. If the catheter damages the endometrium (the lining of the uterus) or touches the fundus, this causes uterine contractions which lead to lower embryo implantation rates. The use of ultrasound during embryo transfer was first discussed in 1995 to allow accurate positioning of the catheter tip near the uterine fundus and hence improve pregnancy rates. The technique has often been described as “cleaner” with the ability to tailor the placement of the embryo to the individual. Ultrasound guided embryo transfer is recommended by NICE and is used in 77% of embryo transfers worldwide. Traditionally, ultrasound guided embryo transfer has been performed using trans-abdominal 2D ultrasound. More recently, ultrasound technology and capabilities have advanced so that 3D and 4D imaging of the uterus can now be achieved, showing finer detail with greater clarity, as well as enabling spatial awareness in terms of the dimensions and volume of the uterus. It is reasonable to assume that more accurate placement of the transfer catheter and the embryo(s) could result in higher pregnancy rates. In a small study, transabdominal 3D ultrasound was used to confirm the correct placement of a trial catheter before embryo transfer, which was not subsequently performed under ultrasound guidance. A second study also confirmed the ability to ensure correct catheter placement using 3D and 4D ultrasound using transabdominal ultrasound, and reported an increase in pregnancy rate from 36.66% to 65%. With the availability of the Kitazato embryo transfer catheter, the ability to perform an embryo transfer using a transvaginal 3D/4D ultrasound scan has become possible. The resolution of images obtained using transvaginal ultrasound appears superior to similar images obtained through transabdominal scanning. The aim of this study is to find out whether this technique results in better pregnancy rates and outcomes.

Who can participate?
Women undergoing fresh or frozen embryo transfer

What does the study involve?
Participants are randomly allocated into either the intervention group or the control group. In the intervention group, a transvaginal ultrasound is performed to guide the embryo transfer. In the control group the embryo placement is carried out using the clinical touch technique. All participants are followed up for 10 months to record the number of live births.

What are the possible benefits and risks of participating?
Benefits may include an improved pregnancy rate. Ultrasound guidance may also reduce the number of failed embryo transfers due to better catheter placement. Risks between the groups should be similar. Ectopic pregnancy rates should be similar between groups and there is likely still to be a miscarriage risk. Intervention group transfers may take slightly longer than control group transfers. Discomfort is likely to be similar in both groups.

Where is the study run from?
Liverpool Women's NHS Foundation Trust (UK)

When is the study starting and how long is it expected to run for?
February 2018 to September 2020 (updated 19/07/2019, previously: June 2019)

Who is funding the study?
Liverpool Women's NHS Foundation Trust (UK)

Who is the main contact?
1. Dr Lewis Nancarrow (public)
2. Mr Richard Russell (scientific)
3. Miss Louise Hardman (public)

Trial website

Contact information



Primary contact

Dr Lewis Nancarrow


Contact details

Hewitt Fertility Centre
Liverpool Women's HNS Foundation Trust
Crown Street
L8 7SS
United Kingdom



Additional contact

Mr Richard Russell


Contact details

Hewitt Fertility Centre
Liverpool Women's NHS Foundation Trust
Crown Street
L8 7SS
United Kingdom



Additional contact

Miss Louise Hardman


Contact details

Liverpool Women's NHS Foundation Trust
Crown Street
L8 7SS
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number

Version 3.0, IRAS 202857

Study information

Scientific title

3D/4D ultrasound guided embryo transfer vs clinical touch technique: a randomised controlled trial



Study hypothesis

Does the use of advanced ultrasound techniques during embryo transfer improve the pregnancy rate and outcome for patients undergoing IVF treatment?
Embryo implantation is a critical step in successful IVF treatment. Correct placement of the embryo(s) within the uterine cavity can result in improved implantation. If the uterine cavity can be assessed in greater detail, is the more accurate placement of the embryo possible and will this improve implantation and pregnancy rates?

Ethics approval

North West - Liverpool Central Research Ethics Committee, 09/12/2016, REC ref: 16/NW/0588

Study design

Prospective randomised parallel trial (unblinded)

Primary study design


Secondary study design

Randomised parallel trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet.




In a non-randomised pilot study of an unselected population (50 patients), an increase in live birth rate biochemical pregnancy rate of 15% was observed in the intervention group compared with a control group. The sample size in this study assumes an expected response rate in the study group of 40% and in the control group of 25%. To achieve an 80% power to detect the difference, with a significance level of 5%, it is calculated that 149 subjects per group will be required. With a withdraw/non-evaluable subject rate of 5%, a total of 157 subjects per group will need to be recruited, leading to a total required sample size of 314 subjects.

Patients will be randomized to the study group or control group using computer generated numbers. The study group will have embryo replacement done under 3D/4D vaginal ultrasound guidance whereas the control group will have the embryo placement done by the clinical touch technique, where the embryo catheter is inserted to 6 cm to the uterine cavity from the external cervical os. The total duration of follow up is 10 months.

Intervention type



Drug names

Primary outcome measure

Live births, recorded at follow up at 10 months

Secondary outcome measures

1. Biochemical pregnancy, defined as urinary pregnancy test positive, at 2 weeks after embryo transfer
2. Clinical pregnancy, defined as presence of intrauterine pregnancy with fetal heart rate >100bpm between 6-8 weeks pregnancy, at 5 weeks after embryo transfer
3. Miscarriage, recorded at 20 weeks after embryo transfer
4. Ectopic pregnancy, recorded at 8 weeks after embryo transfer
5. Multiple pregnancies, recorded at 5 weeks after embryo transfer
6. Failed embryo transfer, recorded at time of procedure
7. Grading of ease of procedure (Easy 1 to Difficult 5), recorded at time of procedure
8. Duration of procedure, recorded at time of procedure
9. Patient experience, assessed by questionnaire following procedure

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. All women undergoing fresh or frozen embryo transfer
2. All women able to provide written informed consent

Participant type


Age group




Target number of participants


Total final enrolment


Participant exclusion criteria

1. Known or suspected hydrosalpinx
2. Fluid within the endometrial cavity
3. Gross distortion of endometrium (e.g. fibroids etc)
4. Previous myomectomy
5. Previous randomization
6. Significant health issues, e.g. HIV, Hepatitis C, Hepatitis B, previous trachelectomy

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Liverpool Women's NHS Foundation Trust
Crown Street
L8 7SS
United Kingdom

Sponsor information


Liverpool Women’s NHS Foundation Trust

Sponsor details

Crown Street
L8 7SS
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

Hewitt Fertility Centre, Liverpool Women's NHS Foundation Trust

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Dissemination will occur through departmental meeting including research meetings. This potentially will extend to national/international conferences and publications in the field of fertility.

IPD sharing statement
The datasets generated and/or analysed during the current study during this study will be included in the subsequent results publication.

Intention to publish date


Participant level data


Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

19/10/2020: The intention to publish date was changed from 30/11/2020 to 01/02/2021. 17/02/2020: The IRAS number has been added. 12/02/2020: The total final enrolment number has been added The following changes were made to the trial record: 1. The recruitment end date was changed from 01/06/2019 to 30/01/2020. 2. The overall end date was changed from 01/06/2020 to 30/09/2020. 3. The intention to publish date was changed from 01/10/2020 to 30/11/2020. 4. The plain English summary was updated to reflect these changes. 02/04/2019: Uploaded protocol (not peer reviewed). 20/07/2018: The following changes have been made to the trial record: 1. The trial end date has been changed from 01/06/2019 to 01/06/2020 2. The recruitment end date has been changed from 01/06/2018 to 01/06/2019 3. The intention to publish date has been changed from 01/01/2021 to 01/10/2020