Pelvic floor muscle contraction during routine pregnancy ultrasound

The intervention is using transabdominal ultrasound scan to visualise maternal pelvic floor muscle contraction as a form of biofeedback during routine fetal anatomy scan, which also uses transabdominal ultrasound. Both components of the scan (fetal anatomy and pelvic floor muscle contraction) will be conducted by sonographers. This is in addition to written information on pelvic floor exercise given at the time of recruitment. The pelvic floor muscle contraction component will involve the participant in supine position with the ultrasound probe placed transversely in the midline in the suprapubic region visualising the bladder base. Women will be asked to observe the ultrasound screen while they perform a pelvic floor muscle contraction. The participant will be oriented to the direction of the bladder base on the screen and the direction of movement of the bladder base. The sonographer instruct a voluntary pelvic floor muscle contraction by saying “relax your thighs, buttocks and tummy muscles. Now, squeeze and lift around your vagina or back passage. Imagine you are trying to hold back urine, or stop passing wind”. These instructions are the same as those on the leaflet provided in the study pack at recruitment. A correct pelvic floor muscle contraction will result in elevation of the bladder base. Each woman will be given up to five attempts to demonstrate a correct pelvic floor muscle contraction during the scan, which will add up to five minutes of scan time. The scan will occur between 18 to 22 weeks gestation of pregnancy. The sonographer at each scan will indicate on the scan report whether the pelvic floor muscle contraction component of the scan has occurred. The written information will consist of a brief summary of the New Zealand Ministry of Health recommendations for pelvic floor muscle exercise in pregnancy, and written instructions on how to perform a correct pelvic floor muscle contraction, and pelvic floor exercise adapted from the Continence New Zealand Pelvic Floor Training Program and independently reviewed by a pelvic floor physiotherapist. Pelvic floor exercise will not be formally prescribed but the written information will advise participants to aim to holding each contraction for 10 seconds then relax for 10 seconds, doing 10 contractions in a row per set, and 3 sets per day until the muscles feel strong then aim to do a maintenance set of 10 strong holds every day forever.