Auckland Bioengineering Institute

Pelvic Floor Study - Measurement of pelvic floor muscles during the child bearing year

What is the purpose of the study?

We hear about it all the time; tears, scars, trauma, infections, urinary incontinence etc. To some extent it could almost put a woman off a vaginal delivery. But does it have to be this way? Can we identify this risk and eliminate some of the fear of childbirth?

Very little is known about how the pelvic floor muscles change during pregnancy and how they stretch during the delivery. This is important to identify because it is the lack of knowledge about these muscles that can lead to damage during delivery. This damage increases the risk of urinary incontinence or pelvic organ prolapse later in life.

Currently, up to 30% of women will damage their internal deep pelvic floor muscle during vaginal delivery and a similar percentage will tear their perineum. We can’t predict who will tear and who won’t at this stage. Our ultimate goal is to reduce the number of women who suffer from long term pelvic floor dysfunction caused by childbirth trauma.

In order to achieve this we need to develop a way to identify who is most at risk of pelvic floor muscle and perineal damage during childbirth. We plan to do this by developing a risk prediction model that will ultimately help women in the future.

We need your help to do this by taking part in this groundbreaking research.

We need women living in Christchurch who are pregnant with their first baby (under 24 weeks’ gestation) to take part in the study.

The study is open until December 2017


Who can participate?

  • Women aged between 18 – 45 years of age who are already pregnant (under 24 week’s gestation) with their first baby.
  • Who are able to attend 3 appointments in the Christchurch area (Avonhead suburb)

You cannot participate in the study if you:

  • If you have had a previous full term pregnancy
  • If you are pregnant with more than one baby
  • If your pregnancy is considered high risk by your lead maternity caregiver
  • If you suffer from any neurological condition such as multiple sclerosis, cerebral palsy, cauda equina syndrome or pudendal neuropathy
  • If you are taking any medications that are known to affect muscle tension (such as muscle relaxants)
  • If you are unable to speak and read the English language well

The study is open until December 2017.


What will you have to do?

To register for the study you need to complete a secure online survey
We will contact you to let you know if you are eligible to take part
We will give you more information about the study and book your first appointment

Appointments: how often, and what happens

First Appointment (18 weeks pregnant). Involves a screening examination and measurements.
Second Appointment (36 weeks pregnant). Involves a consultation and measurements.
Third Appointment (3-6 months post-delivery). Involves a consultation, measurements plus ultrasound, and the completion of an online questionnaire.

Is it safe to participate in this study?

  • Ethics for this project has been reviewed and approved by the Northern A Health and Disability Ethics Committee (HDEC Number LRS/10/07/029/AM09). 
  • The examinations and muscle tests will be done by an experienced female pelvic floor physiotherapist who has over 26 years of experience assessing and treating patients.
  • Your personal information will be stored in a private and confidential manner.
  • The online survey is conducted through a secure website.

Interested? See the below section on how to participate.

Apply to participate

Read the full Patient Information Sheet and Consent Form which describes the study in greater detail. Note: the Patient Information Sheet and Consent Form was updated on 27 September 2016.

Then, if you would like to participate, register your interest and complete the questionnaire.



Investigator contact details:

Melissa Davidson

Melissa Davidson
(PhD Candidate) 
Physiotherapy Specialist – Pelvic Health
Ph: 0274142258


Dr Jennifer Kruger

Dr Jennifer Kruger
(Supervisor and Lead Investigator)                     

Postdoctoral Research Fellow
Ph: 09 923 9968