There is no short answer to this as it has not been specifically studied. There is one study that has shown a tight and strong pelvic floor in elite athletes may increase the risk of instrumental delivery and perineal trauma, and another study showed that women with a higher resting “tone” to their muscles had longer second stage labour.
However, there are many studies showing no impact, or maybe improved birth outcomes in women who are performing antenatal pelvic floor muscle exercises, or Kegels. And we know that antenatal pelvic floor exercises greatly reduce the risk of urinary incontinence after delivery and later in life - so they are super important to do!
Therefore, the answer likely lies in the coordination of the pelvic floor – the ability to contract, and then to relax when needed. Doing pelvic floor muscle exercises improves your awareness and coordination of these muscles – which is likely the most important thing in labour!
There is very high quality evidence to support perineal massage to greatly improve birth outcomes (you can read all about it here). Likely this works in the same way – you are improving your brain-body connection, learning to keep your pelvic floor relaxed as pressure is applied to the perineum.
The takeaway:
- Do your pelvic floor exercises, and make sure you know how to do them properly – both the contraction and relaxation phases
- If you are unsure – see a women’s health physio who can specifically assess and train your technique!
Written by physiotherapist, Fiona Burford
Back In Motion Brighton
Bø, K., Hilde, G., Jensen, J. S., Siafarikas, F., & Engh, M. E. (2013). Too tight to give birth? Assessment of pelvic floor muscle function in 277 nulliparous pregnant women. International Urogynecology Journal: Including Pelvic Floor Dysfunction, 24(12), 2065–2070.
Kruger JA, Dietz HP, Murphy BA (2007) Pelvic floor function in elite nulliparous athletes. Ultrasound Obstet Gynecol 30:81–85
Morkved, S., & Bo, K. (2014). Effect of pelvic floor muscle training during pregnancy and after childbirth on prevention and treatment of urinary incontinence: a systematic review. BRITISH JOURNAL OF SPORTS MEDICINE, 48(4), 299–310.
Sobhgol, S. S., Smith, C. A., Thomson, R., & Dahlen, H. G. (2022). The effect of antenatal pelvic floor muscle exercise on sexual function and labour and birth outcomes: A randomised controlled trial. Women and Birth.