Recovery from Obstetric Anal Sphincter Injury in a Prospective Cohort of First Births

In vitro biomechanical properties of porcine perineal tissues to better understand human perineal tears during delivery

INTRODUCTION

Data concerning the mechanical properties of the perineum during delivery are very limited. In vivo experiments raise ethical issues. The aim of the study was to describe some of the biomechanical properties of each perineal tissue layer collected from sows in order to better understand perineal tears during childbirth.

MATERIAL AND METHODS

Samples of each perineal tissue layer were obtained from the skin, the vagina, the external anal sphincter (EAS), the internal anal sphincter (IAS), and the anal mucosa of fresh dead sows. They were tested in quasi-static uniaxial tension using the testing machine Mach-1®. Tests were performed at a displacement velocity of 0.1 mm·s-1. Stress-strain curves of each perineal tissue layer before the first damage for each sow were obtained and modeled using a hyperelastic Yeoh model described by three coefficients: C1, C2, and C3. Pearson correlation coefficients were calculated to measure the correlation between the C1 hyperelastic coefficient and the duration between the first microfailure and the complete rupture for each perineal tissue layer. Pearson correlation was computed between C1 and the number of microfailures before complete rupture for each tissue.

RESULTS

Ten samples of each perineal tissue layer were analyzed. Mean values of C1 and corresponding standard deviations were 46 ± 15, 165 ± 60, 27 ± 10, 19 ± 13, 145 ± 28 kPa for the perineal skin, the vagina, the EAS, the IAS, and the anal mucosa, respectively. According to this same sample order, the first microfailure in the population of 10 sows appeared at an average of 54%, 27%, 70%, 131%, and 22% of strain. A correlation was found between C1 hyperelastic coefficient and the duration between the first microfailure and the complete rupture (r = 0.7, p = 0.02) or the number of microfailures before complete rupture only for the vagina (r = 0.7, p = 0.02).

CONCLUSIONS

In this population of fresh dead sow's perineum, the vagina and the anal mucosa were the stiffest tissues. The IAS and EAS were more extensible and less stiff. A significantly positive correlation was found between C1 and the duration between the first microfailure and the complete rupture of the vagina, and the duration between the first microfailure and the complete rupture of the vagina.

Associations of pelvic floor dysfunction and postnatal mental health: a systematic review

BACKGROUND

Postpartum mental health conditions are common and can have devastating effects for both mother and infant. Adverse birth outcomes increase the risk of postnatal mental health conditions. Pelvic floor dysfunction (PFD) is a common adverse pregnancy outcome that may be a risk factor for postnatal mental health conditions. There are many studies reporting associations between PFD and postnatal mental health conditions, but no reports have synthesised the current literature as it relates to pregnancy and the postpartum period.

METHODS

A research librarian conducted systematic literature searches using terms concerning PFD, postnatal mental health conditions, and pregnancy. Searches were conducted within PubMed, Embase, CINAHL, Cochrane, and Scopus. Two reviewers independently rated each study for inclusion and study quality. No studies were excluded based on quality.

RESULTS

A total of 47 studies were included for review. Articles addressed sexual dysfunction (n = 11), incontinence (n = 21), perineal laceration (n = 13), pelvic organ prolapse (n = 2), and general pelvic floor symptoms (n = 2) and associations with postnatal mental health conditions. Two articles addressed more than one type of PFD. The majority (44 studies) reported associations between PFD and adverse postnatal mental health conditions.

DISCUSSION

Most studies included for review found consistent associations between PFD and adverse mental health conditions. Healthcare providers should screen for PFD and postnatal mental health conditions early in the postpartum period. Future research should investigate whether the treatment of PFD can modify the associations between PFD and postnatal mental health conditions.

The effects of progesterone on the healing of obstetric anal sphincter damage in female rats

We aimed to evaluate the effects of postpartum progesterone on obstetric anal sphincter injury (OASI) healing in female rats using an experimental OASI model. Twenty-eight female rats were divided into four groups after birth: sham-30, sham-90, progesterone (P4)-30, and P4-90. Moreover, OASI model was established in all groups. Subsequently, except for the sham groups, medroxyprogesterone acetate (0.15 mg) was intramuscularly injected into the P4 groups. After 30 and 90 days, the rats were euthanized under general anesthesia after recording the data. The anal sphincter region was collected for histopathological examination. Progesterone and thiol/disulfide homeostasis studies were performed on blood samples. No significant differences were observed between the groups regarding the external anal sphincter (EAS), internal anal sphincter (IAS), or connective tissue thickness (p = 0.714, p = 0.135, and p = 0.314, respectively). No statistically significant differences in the total thiol, native thiol, disulfide, and progesterone levels were found between the groups (p = 0.917, p = 0.503, p = 0.361, and p = 0.294, respectively). The endometrial thickness was lower in the P4 groups than in the sham groups (p = 0.031). Postpartum progesterone administration did not affect IAS and EAS or connective tissue thickness or disrupt the thiol-disulfide balance. However, this administration led to endometrial thinning.