Levator hiatus dimensions in late pregnancy and the process of labor: a 3- and 4-dimensional transperineal ultrasound study

Siafarikas, Franziska; Stær-Jensen, Jette; Hilde, Gunvor; Bø, Kari; Engh, Marie Ellstrøm

doi:10.1016/j.ajog.2014.02.021

Cited by 39 publications

(42 citation statements)

References 23 publications

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“…Correlation between levator hiatal dimensions and LAM relaxation and labor outcome is therefore expected. However, to what extent levator hiatal dimensions and LAM relaxation may affect the outcome of labor remains a matter of debate, with conflicting results reported in the literature [19][20][21][22]27 . With the introduction of TPU, objective quantitative assessment of pelvic organ mobility, levator hiatal dimensions and their dynamic changes became feasible [28][29][30][31][32][33][34][35] .…”

Section: Discussionmentioning

confidence: 99%

“…Over the past few years, much effort has been spent diagnosing and identifying risk factors for pelvic floor muscle injury, which seems to be the connection between vaginal delivery and the development of prolapse and pelvic floor dysfunction [9][10][11][12][13][14][15][16][17][18] . On the other hand, much less is known about the effect of the pelvic floor on the outcome of labor [19][20][21][22] .…”

Section: Introductionmentioning

confidence: 99%

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Levator ani muscle coactivation at term is associated with longer second stage of labor in nulliparous women

Youssef

Montaguti

Dodaro

et al. 2019

Ultrasound in Obstet & Gyne

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Objective To assess the effect of levator ani muscle (LAM) coactivation at term on outcome of labor in nulliparous women. Methods This was a prospective study of 284 low‐risk nulliparous women with a singleton pregnancy at term recruited before the onset of labor. The anteroposterior diameter of the levator hiatus was measured in each woman on transperineal ultrasound at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva maneuver before and after visual feedback. LAM coactivation was defined as a reduction in the anteroposterior diameter of the levator hiatus on maximum Valsalva maneuver in comparison with that at rest. The association of pelvic hiatal diameter values and LAM coactivation with mode of delivery and duration of labor was assessed. Results No significant difference was found between women who underwent Cesarean delivery and those who had a vaginal delivery with regard to the anteroposterior diameter of the levator hiatus at rest, on pelvic floor muscle contraction and on Valsalva maneuver. Longer second stage of labor was associated with shorter anteroposterior diameter of the levator hiatus on all assessments, but in particular at rest and on Valsalva both before and after visual feedback. LAM coactivation was found in 89 (31.3%) and 75 (26.4%) women before and after visual feedback, respectively. Post visual feedback, women with LAM coactivation had a significantly longer second stage of labor than did those without LAM coactivation (83 ± 63 vs 63 ± 42 min; P = 0.006). On Cox regression analysis, LAM coactivation post visual feedback was an independent predictor of longer second stage of labor (adjusted hazard ratio, 1.499 (95% CI, 1.076–2.087); P = 0.017). Conclusion LAM coactivation in nulliparous women at term is associated with a longer second stage of labor. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Levator ani muscle coactivation at term is associated with longer second stage of labor in nulliparous women

Youssef

Montaguti

Dodaro

et al. 2019

Ultrasound in Obstet & Gyne

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“…[20][21][22] The study was conducted at Akershus University Hospital in Norway from January 2010 to October 2012 (ClinicalTrials.gov NCT01045135). The design was longitudinal, with the participants undergoing a clinical examination and answering an electronic questionnaire at five fixed time points relative to the time of birth.…”

Section: Methodsmentioning

confidence: 99%

Change in pelvic organ support during pregnancy and the first year postpartum: a longitudinal study

Reimers

Stær-Jensen

Siafarikas

et al. 2015

BJOG

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Summary Objective To describe changes in pelvic organ support from mid pregnancy until 1 year postpartum among nulliparous pregnant women, and to examine whether delivery route affects changes in pelvic organ support.Design Prospective cohort study. Setting Akershus University Hospital in Norway.Population A cohort of 300 nulliparous pregnant women included at mid-pregnancy.Methods Pelvic organ support assessed at 21 and 37 weeks of gestation, and again at 6 weeks, 6 months, and 12 months postpartum, by the use of the Pelvic Organ Prolapse Quantification (POP-Q) system. Linear mixed model was used to assess longitudinal change in pelvic organ support.Main outcome measures Prevalence of anatomic POP. Change in POP-Q variables over time and between delivery groups.Results The prevalence of anatomic POP ranged from 0 to 10%. Vaginal POP-Q points made a cranial shift from mid to late pregnancy, a caudal shift following delivery, and again a cranial shift after 6 weeks postpartum. Postpartum change was present following both vaginal and caesarean deliveries, but was more pronounced following vaginal delivery. The perineal body and genital hiatus became longer from mid to late pregnancy, and shortened after 6 weeks postpartum. At 12 months postpartum all POP-Q points, except cervix, had recovered to baseline in the vaginal delivery group.Conclusions The prevalence of anatomic POP was low in this cohort. There was change in pelvic organ support both during pregnancy and following vaginal as well as caesarean delivery. The short-term ability to recover was good after the first pregnancy and delivery.Keywords Delivery, pelvic organ support, POP, postpartum, pregnancy, primipara.Tweetable Abstract Pelvic organ support changes during pregnancy. A contribution to the risk of POP?

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“…13–17 To assess changes in the PFMs in pregnancy, clinical studies utilize an imaging parameter referred to as the levator hiatus. 18,19 However, dimensions of levator hiatus provide very limited information relevant to PFM structure and function and do not correlate with strength or endurance of PFM contraction. 20 Thus, our limited understanding of the impact of pregnancy and delivery on the structure and function of PFMs precludes identification of targets for preventive strategies.…”

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confidence: 99%

Pregnancy-induced adaptations in the intrinsic structure of rat pelvic floor muscles

Alperin

Lawley

Esparza

et al. 2015

American Journal of Obstetrics and Gynecology

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OBJECTIVE Maternal birth trauma to the pelvic floor muscles (PFMs) is a major risk factor for pelvic floor disorders. Modeling and imaging studies suggest that demands placed on PFMs during childbirth exceed their physiologic limits; however many parous women do not sustain PFM injury. Here we determine whether pregnancy induces adaptations in PFM architecture, the strongest predictor of muscle function, and/or intramuscular extracellular matrix (ECM), responsible for load bearing. To establish if parallel changes occur in muscles outside of the PFM, we also examined a hind limb muscle. STUDY DESIGN Coccygeus, iliocaudalis, pubocaudalis, and tibialis anterior of 3-month-old Sprague-Dawley virgin, mid-pregnant, and late-pregnant; 6-month-old virgin; and 4- and 12-week postpartum rats (N = 10/group) were fixed in situ and harvested. Major architectural parameters determining muscle’s excursion and force-generating capacity were quantified, namely, normalized fiber length (Lfn), physiologic cross-sectional area, and sarcomere length. Hydroxyproline content was used as a surrogate for intramuscular ECM quantity. Analyses were performed by 2-way analysis of variance with Tukey post hoc testing at a significance level of .05. RESULTS Pregnancy induced a significant increase in Lfn in all PFMs by the end of gestation relative to virgin controls. Fibers were elongated by 37% in coccygeus (P < .0001), and by 21% in iliocaudalis and pubocaudalis (P < .0001). Importantly, no Lfn change was observed in the tibialis anterior. Physiologic cross-sectional area and sarcomere length were not affected by pregnancy. By 12 weeks’ postpartum, Lfn of all PFMs returned to the prepregnancy values. Relative to virgin controls, ECM increased by 140% in coccygeus, 52% in iliocaudalis, and 75% in pubocaudalis in late-pregnant group, but remained unchanged across time in the tibialis anterior. Postpartum, ECM collagen content returned to prepregnancy levels in iliocaudalis and pubocaudalis, but continued to be significantly elevated in coccygeus (P < .0001). CONCLUSION This study demonstrates that pregnancy induces unique adaptations in the structure of the PFMs, which adjust their architectural design by adding sarcomeres in series to increase fiber length as well as mounting a substantial synthesis of collagen in intramuscular ECM.

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Levator hiatus dimensions in late pregnancy and the process of labor: a 3- and 4-dimensional transperineal ultrasound study

Cited by 39 publications

References 23 publications

Levator ani muscle coactivation at term is associated with longer second stage of labor in nulliparous women

Levator ani muscle coactivation at term is associated with longer second stage of labor in nulliparous women

Change in pelvic organ support during pregnancy and the first year postpartum: a longitudinal study

Pregnancy-induced adaptations in the intrinsic structure of rat pelvic floor muscles

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