Contraction of the levator ani muscle during Valsalva maneuver (coactivation) is associated with a longer active second stage of labor in nulliparous women undergoing induction of labor

Pelvic floor dysfunction (PFD) due to vaginal delivery is related to tear of levator ani muscle (LAM) that potentially lead to the impairment of quality of life among women. A number of attempts to predict LAM injury after vaginal delivery had been conducted. This study aims to appraise the accuracy of several prediction index determining LAM injury after vaginal delivery. We conducted a search in Cochrane Library®, Pubmed®, and Medline® with the keywords of “pelvic floor dysfunction” AND “vaginal delivery” AND “prediction.” Critical appraisal determining the validity, importance, and applicability (VIA) was conducted by 2 independent authors. After 6 weeks to 3 months’ duration of follow up, the incidence of LAM avulsion was varied from 15.4% to 35.6% from three studies. Multivariate analysis showed that forceps delivery, OASIS, and active second stage (OR 3.8; 3.1; 1.61; respectively) as the most influential factors for LAM incidence. Maternal age and time spent in active pushing were also contributed to LAM incidence. OASIS and second stage of labor could be used as the most influential components of prediction index for LAM incidence. Prediction indexes for LAM incidence are developed. OASIS and second stage of labor are acknowledged as two most influential variables among three appraised studies.

Download Full-text

Fetal head circumference and length of second stage of labor are risk factors for levator ani muscle injury, diagnosed by 3-dimensional transperineal ultrasound in primiparous women

American Journal of Obstetrics and Gynecology ◽

10.1016/j.ajog.2009.03.028 ◽

2009 ◽

Vol 201 (1) ◽

pp. 91.e1-91.e7 ◽

Cited By ~ 124

Author(s):

Dan V. Valsky ◽

Michal Lipschuetz ◽

Angelika Bord ◽

Ido Eldar ◽

Baruch Messing ◽

...

Keyword(s):

Risk Factors ◽

Muscle Injury ◽

Levator Ani ◽

Levator Ani Muscle ◽

Fetal Head ◽

Second Stage Of Labor ◽

3 Dimensional ◽

Second Stage ◽

Levator Ani Muscle Injury ◽

Primiparous Women

Download Full-text

Prolonged Second Stage of Labor and Levator Ani Muscle Injuries

Global Journal of Health Science ◽

10.5539/gjhs.v7n1p267 ◽

2014 ◽

Vol 7 (1) ◽

Cited By ~ 3

Author(s):

Vajihe Marsoosi ◽

Ashraf Jamal ◽

Laleh Eslamian ◽

Sonia Oveisi ◽

Shokohossadat Abotorabi

Keyword(s):

Levator Ani ◽

Levator Ani Muscle ◽

Muscle Injuries ◽

Second Stage Of Labor ◽

Second Stage

Download Full-text

A Simulation Analysis of Maternal Pelvic Floor Muscle

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph182010821 ◽

2021 ◽

Vol 18 (20) ◽

pp. 10821

Author(s):

Rongrong Xuan ◽

Mingshuwen Yang ◽

Yajie Gao ◽

Shuaijun Ren ◽

Jialin Li ◽

...

Keyword(s):

Pelvic Floor ◽

Pelvic Floor Muscle ◽

Levator Ani ◽

Stress And Strain ◽

Delivery Mode ◽

Levator Ani Muscle ◽

Pelvic Mri ◽

Second Stage Of Labor ◽

Attachment Point ◽

Second Stage

Pelvic floor disorder (PFD) is a common disease affecting the quality of life of middle-aged and elderly women. Pelvic floor muscle (PFM) damage is related to delivery mode, fetal size, and parity. Spontaneous vaginal delivery causes especially great damage to PFM. The purpose of this study was to summarize the characteristics of PFM action during the second stage of labor by collecting female pelvic MRI (magnetic resonance imaging) data and, further, to try to investigate the potential pathogenetic mechanism of PFD. A three-dimensional model was established to study the influence factors and characteristics of PFM strength. In the second stage of labor, the mechanical responses, possible damage, and the key parts of postpartum lesions of PFM due to the different fetal biparietal diameter (BPD) sizes were analyzed by finite element simulations. The research results showed that the peak stress and strain of PFM appeared at one-half of the delivery period and at the attachment point of the pubococcygeus to the skeleton. In addition, during the simulation process, the pubococcygeus was stretched by about 1.2 times and the levator ani muscle was stretched by more than two-fold. There was also greater stress and strain in the middle area of the levator ani muscle and pubococcygeus. According to the statistics, either being too young or in old maternal age will increase the probability of postpartum PFM injury. During delivery, the entire PFM underwent the huge deformation, in which the levator ani muscle and the pubococcygeus were seriously stretched and the attachment point between the pubococcygeus and the skeleton were the places with the highest probability of postpartum lesions.

Download Full-text

Fundal pressure in second stage of labor (Kristeller maneuver) is associated with increased risk of levator ani muscle avulsion

Ultrasound in Obstetrics and Gynecology ◽

10.1002/uog.19085 ◽

2018 ◽

Vol 53 (1) ◽

pp. 95-100 ◽

Cited By ~ 17

Author(s):

A. Youssef ◽

G. Salsi ◽

I. Cataneo ◽

G. Pacella ◽

C. Azzarone ◽

...

Keyword(s):

Levator Ani ◽

Levator Ani Muscle ◽

Second Stage Of Labor ◽

Second Stage ◽

Increased Risk ◽

Levator Ani Muscle Avulsion ◽

Fundal Pressure

Download Full-text

Effects of Nonlinear Muscle Elasticity on Pelvic Floor Mechanics During Vaginal Childbirth

Journal of Biomechanical Engineering ◽

10.1115/1.4002558 ◽

2010 ◽

Vol 132 (11) ◽

Cited By ~ 24

Author(s):

Xinshan Li ◽

Jennifer A. Kruger ◽

Martyn P. Nash ◽

Poul M. F. Nielsen

Keyword(s):

Experimental Data ◽

Pelvic Floor ◽

Vaginal Delivery ◽

Pelvic Floor Dysfunction ◽

Levator Ani ◽

Head Model ◽

Levator Ani Muscle ◽

Fetal Head ◽

Second Stage Of Labor ◽

Second Stage

The role of the pelvic floor soft tissues during the second stage of labor, particularly the levator ani muscle, has attracted much interest recently. It has been postulated that the passage of the fetal head through the pelvis may cause excessive stretching of the levator ani muscle, which may lead to pelvic floor dysfunction and pelvic organ prolapse later in life. In order to study the complex biomechanical interactions between the levator ani muscle and the fetal head during the second stage of labor, finite element models have been developed for quantitative analysis of this process. In this study we have simulated vaginal delivery using individual-specific anatomical computer models of the pelvic floor interacting with a fetal head model with minimal restrictions placed upon its motion. Two constitutive relations were considered for the levator ani muscle (of exponential and neo-Hookean forms). For comparison purposes, the exponential relation was chosen to exhibit much greater stiffening at higher strains beyond the range of the experimental data. We demonstrated that increased nonlinearity in the elastic response of the tissues leads to considerably higher (56%) estimated force required for delivery, accompanied by a more homogeneous spatial distribution of maximum principal stretch ratio across the muscle. These results indicate that the form of constitutive relation beyond the presently available experimental data markedly affects the estimated function of the levator ani muscle during vaginal delivery, due to the large strains that occur. Further experimental data at higher strains are necessary in order to more reliably characterize the constitutive behavior required for modeling vaginal childbirth.

Download Full-text

Prolonged interpregnancy interval: how does it impact the length of second stage of labor?

Journal of Perinatal Medicine ◽

10.1515/jpm-2020-0171 ◽

2020 ◽

Vol 48 (8) ◽

pp. 811-818

Author(s):

Nicole B. Kurata ◽

Keith K. Ogasawara ◽

Kathryn L. Pedula ◽

William A. Goh

Keyword(s):

Perinatal Outcomes ◽

Kaiser Permanente ◽

Second Stage Of Labor ◽

Second Stage ◽

Labor Duration ◽

Nulliparous Women ◽

Multiparous Women ◽

Comparison Groups ◽

Maternal And Neonatal Outcomes ◽

Interpregnancy Intervals

AbstractObjectivesShort interpregnancy intervals (IPI) have been linked to multiple adverse maternal and neonatal outcomes, but less is known about prolonged IPI, including its relationship with labor progression. The objective of the study was to investigate whether prolonged IPIs are associated with longer second stages of labor.MethodsA perinatal database from Kaiser Permanente Hawaii was used to identify 442 women with a prolonged IPI ≥60 months. Four hundred forty two nulliparous and 442 multiparous women with an IPI 18–59 months were selected as comparison groups. The primary outcome was second stage of labor duration. Perinatal outcomes were compared between these groups.ResultsThe median (IQR) second stage of labor duration was 76 (38–141) min in nulliparous women, 15 (9–28) min in multiparous women, and 18 (10–38) min in women with a prolonged IPI (p<0.0001). Pairwise comparisons revealed significantly different second stage duration in the nulliparous group compared to both the multiparous and prolonged IPI groups, but no difference between the multiparous and prolonged IPI groups. There was a significant association with the length of the IPI; median duration 30 (12–61) min for IPI ≥120 months vs. 15 (9–27) min for IPI 18–59 months and 16 (9–31) min for IPI 60–119 months (p=0.0014).ConclusionsThe second stage of labor did not differ in women with a prolonged IPI compared to normal multiparous women. Women with an IPI ≥120 months had a significantly longer second stage vs. those with a shorter IPI. These findings provide a better understanding of labor progression in pregnancies with a prolonged IPI.

Download Full-text