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Preparing the Pelvic Floor for Birth

Birthing is not 100% predictable. Physiotherapists working in pelvic health have a unique set of skills and knowledge around muscle function that makes us very well equipped to help women “prepare the pelvic floor for birth”.

The aim of preparing the pelvic floor for birth is to achieve the best outcomes for both mother and baby. Physiotherapists are able to assess:

  • Levator distensibility

  • Pelvic floor muscle function

  • Pelvic/ hip mobility

  • Bear down manoeuvre

Together with your health care provider, we can discuss and make decisions on your individual risk of birth injury with vaginal delivery.

Levator hiatal distensibility is ballooning of the levator hiatus (the gap in the midline of the pelvic floor through which the urethra, vagina, and rectum passes). This questions whether the pelvic floor can contract, relax, stretch and bounce back to resting tone.

GH + PB is a measurement easily performed in clinic and there is good evidence that a larger hiatal area at 37 weeks of pregnancy relates to a shorter 2nd stage of labour and reduced risk of instrumental delivery.

A measurement of GH (genital hiatus) + PB (perineal body) on bearing down has a strong relationship to the levator hiatal area on diagnostic ultrasound.

A GH + PB length of 10cm corresponds to an ultrasound area 40cm2. The average baby head at delivery is 33-37cm.

We usually commence our first birth preparation session after the 20 week gestation scan. This allows for placenta previa and a short cervix, both contraindications to an internal exam, to be cleared prior to performing an internal examination. We always ask for your birth providers clearance to perform this.

A lack of distensibility of the levator hiatus at 36+/40 of pregnancy may lead to an instrumental birth and therefore potentially a higher risk of levator muscle/ fascial trauma and 3rd or 4th degree perineal tears. There are some factors that may predict pelvic floor trauma, and we want to screen for these in preparation for birth.

  • History of pelvic pain e.g. endometriosis, adenomyosis, PCOS

  • Overactive bladder

  • Dyspareunia

  • Vaginismus

  • Voiding dysfunction: hesitancy, slow flow, incomplete emptying (without Hx of UTI’s)

  • Functional constipation

  • Age of first birth

  • History of trauma (sexual abuse)

  • Previous traumatic birth

  • POP/ incontinence

  • Pregnancy related pelvic girdle pain (? Hypertonic pelvic floor link)

At 20+ weeks gestation we measure:

  • Pelvic floor muscle strength, tone and the ability for it to relax

  • GH + PB (distensibility)

  • Bear down manoeuvre (BDM)/ technique o Motor pattern of bearing down o Pelvic floor should relax and lengthen

From this initial baseline assessment, together with any identified risk factors, we can recognise and work on any potential barriers to vaginal delivery. This may be, for example, a poor bear down technique, or a hypertonic pelvic floor. We may not need to do anything until we re-assess again at 36 weeks (after some significant hormonal changes 32-35 weeks).

Treatment may include:

  • Pelvic floor muscle training o Optimise tone/ tension

  • Improve effectiveness of the bear down manoeuvre

  • Perineal massage o > 34 weeks o 1-2 x week increasing to daily by 36 weeks o 5-10 mins

  • Pelvic stretches/ yoga

  • Mindfulness and meditation

  • Counselling high risk patients and liaising with care providers

Beyond 36 weeks gestation we continue to measure and treat where necessary. Our goal is to optimise the pelvic floor distensibility for birth, create ideal bear down and breathing techniques and prepare the perineum for birth through massage. Education is a huge part of preparing your body birth and we love working with our pregnant mums and their care providers to create the best possible outcomes for both mum and baby.

Please get in touch if you would like to book in with a Women's Health Physiotherapist to help you prepare for birth!

(02) 4384 3395

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