Postnatal pelvic floor muscle stiffness measured by vaginal elastometry in women with obstetric anal sphincter injury: a pilot study

Association of pre-pregnancy body mass index and gestational weight gain on postpartum pelvic floor muscle morphology and function in Chinese primiparous women: A retrospective cohort study

OBJECTIVE

Our study aimed to investigate the association between maternal pre-pregnancy body mass index (BMI), gestational weight gain (GWG), and impaired pelvic floor muscle (PFM) morphology and function during the early postpartum period.

METHODS

This retrospective cohort study was conducted at Shanghai First Maternity and Infant Hospital from December 2020 to December 2022. A total of 1118 primiparous women with singleton pregnancies who underwent vaginal deliveries and participated in postpartum PFM assessments were included. Maternal pre-pregnancy BMI and GWG were considered as exposures. PFM morphology and function impairment were the primary outcomes. PFM morphology impairment, defined as levator ani muscle avulsion, was assessed using transperineal ultrasound. PFM function impairment, manifested as diminished PFM fiber strength, was assessed through vaginal manometry. Multivariable logistic regression analysis was employed to calculate adjusted odds ratios (aOR) with 95% confidence intervals (CI). Restricted cubic spline models were used to validate and visualize the relationship.

RESULTS

Women with lower pre-pregnancy BMI were at an increased risk of levator ani muscle avulsion (aOR = 1.73, 95% CI: 1.10-2.70, P = 0.017), particularly when combined with excessive GWG during pregnancy (aOR = 3.20, 95% CI: 1.15-8.97, P = 0.027). Lower pre-pregnancy BMI was also identified as an independent predictor of PFM weakness (aOR = 1.53, 95% CI: 1.08-2.16, P = 0.017 for type I fiber injuries). Notably, regardless of the avulsion status, both underweight and overweight/obese women faced an elevated risk of reduced PFM strength (aOR = 1.74, 95% CI: 1.17-2.59, P = 0.006 for underweight women with type I fiber injuries; aOR = 1.67, 95% CI: 1.06-2.64, P = 0.027; and aOR = 1.73, 95% CI: 1.09-2.76, P = 0.021 for overweight/obese women with type I and type II fibers injuries, respectively).

CONCLUSIONS

Both lower and higher pre-pregnancy BMI, as well as excessive GWG, were strongly associated with PFM impairments. These findings highlighted the critical importance of comprehensive weight management throughout pregnancy to effectively promote women's pelvic health.

The predicting value of the ratio of levator hiatus diameter to fetal head circumference in pregnant women at 37 weeks of gestation in the progression of the second stage of labor and levator ani injury 6 weeks postpartum

Objective

This study investigated the predicting value of the ratio of levator hiatus diameter (LHS) to fetal head circumference (HC) in pregnant women at 37 weeks of gestation in the progression of the second stage of labor and levator ani injury 6 weeks postpartum.

Methods

A total of 120 first-time women who gave vaginal delivery at 37 weeks of pregnancy were selected as the subjects in our hospital during March 2021 to March 2022. The subjects were divided into the second stage of labor > 1 h group and the second stage of labor ≤ 1 h group, according to the delivery time of the second stage of labor. According to the 6-week postpartum follow-up ultrasound examination with or without levator ani injury, they were divided into levator ani injury group and no injury group. All primipara women underwent three-dimensional ultrasonography at 37 weeks of gestation, and the resting LHS, Valsalva LHS, fetal HC and the ratio of resting LHS and fetal HC were compared. The correlation between these factors and the length of the second labor stage was analyzed using Pearson correlation analysis. The value of these factors in predicting labor progression and postpartum levator ani injury was assessed by receiver operating characteristic (ROC) curves.

Results

The resting LHS, Valsalva LHS and the ratio of resting LHS and fetal HC in the levator ani injury group were lower than these in the no injury group, while fetal HC in the levator ani injury group was higher than that in the no injury group (P < 0.05). The resting LHS, Valsalva LHS and the ratio of resting LHS and fetal HC in the second stage of labor > 1 h group were lower than these in the second stage of labor ≤ 1 h group, while fetal HC in the second stage of labor > 1 h group was higher than that in the second stage of labor ≤ 1 h group (P < 0.05). A significant negative correlation was observed between resting LHS/HC and total labor process (=-0.333, P < 0.01). ROC curve analysis showed that the AUCs of resting LHS, Valsalva LHS, HC, and resting LHS/HC ratio in predicting prolongation of the second stage of labor were 0.741, 0.740, 0.702, and 0.843 respectively. Besides, the AUCs of resting LHS, Valsalva LHS, HC, and resting LHS/HC ratio in predicting the total labor process were 0.657, 0.684, 0.768, and 0.836 respectively. The AUCs of resting LHS, Valsalva LHS, HC, and resting LHS/HC ratio in predicting postpartum levator ani muscle injury were 0.769, 0.773, 0.747, and 0.885 respectively.These results suggested that the ratio of resting LHS and fetal HC may have certain clinical value in predicting levator ani injury in pregnant women.

Conclusion

LHS, fetal HC and the ratio of resting LHS and fetal HC are significantly correlated with labor progression and postpartum levator ani injury, which have certain value in predicting labor progress and postpartum levator ani injury. Therein, the ratio of resting LHS and fetal HC has the highest predictive value, and early detection of the ratio of resting LHS and fetal HC is helpful to guide the selection of appropriate delivery mode.

Vaginal Electrical Stimulation for Postpartum Neuromuscular Recovery: A Randomized Clinical Trial

OBJECTIVE

The aim of this study was to compare 3-month postpartum anal incontinence symptoms in women who sustain obstetric anal sphincter injuries and begin immediate vaginal electrical stimulation versus sham therapy.

METHODS

In this double-blind randomized controlled trial, women who sustained obstetric anal sphincter injuries were randomized to receive self-administered vaginal electrical stimulation using a commercial device or sham therapy with an identical device. Anal incontinence symptom severity was assessed at 1 week (baseline) and again at 13 weeks postpartum using the Fecal Incontinence Severity Index. The primary outcome was anal incontinence symptom severity measured by the total Fecal Incontinence Severity Index score at 13 weeks postpartum.

RESULTS

Between February 2016 and September 2018, 48 women completed a 13-week follow-up. At 13 weeks postpartum, median Fecal Incontinence Severity Index scores were higher (more severe) in the vaginal electrical stimulation group (12; interquartile range, 0-23) than in the sham group (4; interquartile range, 0-10) (P = 0.04). Unlike the vaginal electrical stimulation group, the improvement in Fecal Incontinence Severity Index scores in the sham group (vaginal electrical stimulation: 12 [interquartile range, 8-22] to 12 [interquartile range, 0-23] [P = 0.12] vs sham: 12 [interquartile range, 6-18] to 4.0 [interquartile range, 0-11] [P < 0.001]) met the threshold for clinical significance based on the minimum important difference of the Fecal Incontinence Severity Index.

CONCLUSION

At 13 weeks postpartum, women who underwent postpartum vaginal electrical stimulation reported more anal incontinence symptoms compared with those receiving sham therapy. Vaginal electrical stimulation after obstetric anal sphincter injury was not beneficial in reducing anal incontinence symptoms and may impede recovery.