The levator ani muscle during pregnancy and major levator ani muscle defects diagnosed postpartum: a three‐ and four‐dimensional transperineal ultrasound study

Abstract

Objective To investigate associations between levator hiatus area and levator ani muscle function during pregnancy and major levator ani muscle defects postpartum.Design Observational prospective cohort study.Setting University hospital, Norway.Sample A cohort of 234 nulliparous women at 21 and 37 weeks of gestation, and at 6 weeks postpartum.Methods Ultrasound measurements of the levator hiatus at rest, during pelvic floor muscle contraction, and during the Valsalva manoeuvre were taken at 21 and 37 weeks of gestation. Levator ani muscle function was estimated as the percentage changes in levator ani muscle length from rest to contraction, and the level of muscle stretch during the Valsalva manoeuvre. Major levator ani muscle defects were diagnosed at 6 weeks postpartum using tomographic ultrasound imaging.Main outcome measures Associations between ultrasound measurements antepartum and major levator ani muscle defects postpartum.Results Women with major levator ani muscle defects postpartum had significantly smaller levator hiatus area at rest and during the Valsalva manoeuvre at mid-pregnancy (mean difference 1.03 cm 2 , 95% CI 0.31-1.76; 2.92 cm 2 , 95% CI 1.77-4.07), and at 37 weeks of gestation (mean difference 1.47 cm 2 , 95% CI 0.62-2.32; 2.84 cm 2 , 95% CI 0.88-4.80), than women without such defects.They also had significantly less shortening of the levator ani muscle during contraction at 37 weeks of gestation.Conclusions Smaller levator hiatus area at rest and during the Valsalva manoeuvre at mid and late pregnancy, and less shortening of the levator ani muscle during contraction at 37 weeks of gestation, are associated with major levator ani muscle defects postpartum.Keywords Levator hiatus, major levator ani muscle defects, pregnancy, transperineal ultrasound.Please cite this paper as: Siafarikas F, Staer-Jensen J, Hilde G, Bø K, Ellström Engh M. The levator ani muscle during pregnancy and major levator ani muscle defects diagnosed postpartum: a three-and four-dimensional transperineal ultrasound study.

New Method for Assessment of Levator Avulsion Injury: A Comparative Elastography Study

“…However, as studies have shown, forceps delivery appears to be a risk factor for a higher grade of pelvic floor trauma. Additionally, more potential risk factors such as age or fetal head circumference have been identified to be linked with more severe damage to the levator ani . We only considered these parameters to describe the patient collective.…”

“…We only considered these parameters to describe the patient collective. On the other hand, it is possible that the extent of injury is mainly attributable to individual tissue character rather than to the factors mentioned above . Future studies will have to consider the influence of the named further variables.…”

“…While minor changes such as irreversible overdistension are more common, major changes (eg, avulsion) have a more severe impact on the levator ani. They have been identified to be the cause for prolapse and a higher rate of prolapse recurrence after surgery . This seems to apply especially when avulsion persists …”

“…The extent of injury is proportional to the force applied to the muscle, and once a certain limit is exceeded irreversible damage occurs . It has also been shown that the medial portions of the muscle are most prone to injury as they undergo most of the stretching due to their short initial length . Childbirth is particularly responsible for pelvic floor trauma as the crowning of the fetal head forces all parts of the levator ani to stretch immensely .…”

Investigating the Performance of a Fractal Ultrasonic Transducer Under Varying System Conditions

“…Ultrasonic sensors are used for imaging in various fields of science and engineering, ranging from fetal scanners [1][2][3][4][5] to non-destructive testing and evaluation of nuclear power stations [6][7][8]. Ultrasound transducers are the components which generate and detect sound waves, converting electrical energy to mechanical energy (and vice versa) through vibrations induced on the transducer [9].…”