Displacement and recovery of the vesical neck position during pregnancy and after childbirth

Longitudinal Study of Pelvic Floor Characteristics Before, During, and After Pregnancy in Nulliparous Women

OBJECTIVES

To investigate the changes in the pelvic floor before, during, and after pregnancy in the same collective of nulliparous women.

METHODS

In a prospective observational pilot study between April 2015 and June 2019 in nulliparous women with planned pregnancy, we used the pelvic organ prolapse quantification (POP-Q) system; a 2-dimensional (2D) sonography to investigate the bladder neck, cervix, and anorectal junction positions; and a 3D/4D sonography to measure the hiatus of the levator ani muscle (LH area) during Valsalva maneuver. Five visits were planned: 1 before, 3 during, and 1 visit after pregnancy.

RESULTS

Twenty-four women participated in the study. We achieved a minimum of 2 visit measurements from 10 women who became pregnant. The LH area decreased during the first trimester and then increased until the third trimester. Postpartum, the LH area reached the prepregnancy state. We observed changes in the bladder neck mobility, bladder neck position, cervix, and anorectal junction from the first trimester. Postpartum, the bladder neck mobility was higher, and the position of the bladder neck and anorectal junction was lower than before pregnancy. We observed no remarkable changes in the POP-Q state during pregnancy.

CONCLUSION

This was the first study to investigate pelvic floor characteristics in the same collective before, during, and after pregnancy. We observed pelvic floor changes from the prepregnancy state to the first trimester to postpartum. The study results need to be confirmed in a larger study.

Transabdominal ultrasound to assess the displacement of the bladder base during abdominal and pelvic floor contractions in continent parous versus nulliparous women

INTRODUCTION AND HYPOTHESIS

The effect of different abdominal contractions on the position of pelvic organs in parous women during postpartum exercises has not been sufficiently assessed. The aim of this study was to evaluate the displacement of the bladder base (BB) during different pelvic floor and abdominal contractions in parous women compared to nulliparous women. We hypothesised that abdominal and perineal contractions will produce a disparate effect on the position of the BB between groups.

METHODS

Cross-sectional study including a convenience sample of 63 volunteers (35 nulliparous vs. 28 postpartum women). Transabdominal ultrasound was used in mode B to image the displacement of the BB. The protocol included six different pelvic floor and abdominal contractions commonly used in postpartum rehabilitation.

RESULTS

The BB elevated significantly more in the postpartum group compared to nulliparous women when performing submaximal contraction of pelvic floor and transversus abdominis muscles simultaneously with axial elongation of the back (0.93 ± 0.55 cm in parous women vs. 0.66 ± 0.46 cm in nulliparous women). In contrast, the BB was found to descend significantly during a curl-up contraction in both groups (0.93 ± 0.55 cm in parous women vs. 0.66 ± 0.46 cm in nulliparous women).

CONCLUSIONS

The overall results of this study showed that perineal and superficial abdominal contractions produced different immediate effects compared to deep abdominal contractions on the displacement of BB in parous and nulliparous women. Further research is required to assess the long-term effects of these contractions.

Biomechanical trade-offs in the pelvic floor constrain the evolution of the human birth canal

Compared with most other primates, humans are characterized by a tight fit between the maternal birth canal and the fetal head, leading to a relatively high risk of neonatal and maternal mortality and morbidities. Obstetric selection is thought to favor a spacious birth canal, whereas the source for opposing selection is frequently assumed to relate to bipedal locomotion. Another, yet underinvestigated, hypothesis is that a more expansive birth canal suspends the soft tissue of the pelvic floor across a larger area, which is disadvantageous for continence and support of the weight of the inner organs and fetus. To test this "pelvic floor hypothesis," we generated a finite element model of the human female pelvic floor and varied its radial size and thickness while keeping all else constant. This allowed us to study the effect of pelvic geometry on pelvic floor deflection (i.e., the amount of bending from the original position) and tissue stresses and stretches. Deflection grew disproportionately fast with increasing radial size, and stresses and stretches also increased. By contrast, an increase in thickness increased pelvic floor stiffness (i.e., the resistance to deformation), which reduced deflection but was unable to fully compensate for the effect of increasing radial size. Moreover, larger thicknesses increase the intra-abdominal pressure necessary for childbirth. Our results support the pelvic floor hypothesis and evince functional trade-offs affecting not only the size of the birth canal but also the thickness and stiffness of the pelvic floor.

Stress urinary incontinence in pregnant women: a review of prevalence, pathophysiology, and treatment

INTRODUCTION AND HYPOTHESIS

Stress urinary incontinence (SUI) is the most common type of urinary incontinence (UI) in pregnant women and is known to have detrimental effects on the quality of life in approximately 54.3 %. Pregnancy is the main risk factor for the development of SUI. This review provides details of the pathophysiology leading to SUI in pregnant women and SUI prevalence and treatment during pregnancy.

METHODS

We conducted a PubMed search for English-language and human-study articles registered from January 1990 to September 2012. This search was performed for articles dealing with prevalence and treatment of SUI during pregnancy. In the intervention studies, we included studies that used a randomized controlled trial (RCT) design or studies comparing a treatment intervention to no treatment.

RESULTS

A total of 534 articles were identified; 174 full-text articles were reviewed, and 28 of them met eligibility criteria and are reported on here. The mean prevalence of SUI during pregnancy was 41 % (18.6-60 %) and increased with gestational age. The increasing pressure of the growing uterus and fetal weight on pelvic-floor muscles (PFM) throughout pregnancy, together with pregnancy-related hormonal changes, may lead to reduced PFM strength as well as their supportive and sphincteric function. These cause mobility of the bladder neck and urethra, leading to urethral sphincter incompetence. Pelvic floor muscle exercise (PFME) is a safe and effective treatment for SUI during pregnancy, without significant adverse effects.

CONCLUSIONS

Understanding these issues can be useful for health-care professionals when informing and counseling pregnant women to help prevent SUI during pregnancy and the postpartum period.

Incontinence, bladder neck mobility, and sphincter ruptures in primiparous women

Objective

To compare the function of the pelvic floor in primiparae before and during pregnancy with the status post partum concerning symptoms of incontinence, sphincter ruptures, bladder-neck mobility and the influence of the different modes of deliveries.

Methods

Questionnaire evaluating symptoms of urinary and anal incontinence in nulliparous women before and after delivery and correlating these symptoms with functional changes of the pelvic floor based on a careful gynaecologic examination as well as perineal and endoanal ultrasound.

Results

112 women were included in our study and came for the first visit, 99 women returned for follow-up 6 months after childbirth. Stress and flatus incontinence significantly increased from before pregnancy (3 and 12%) to after childbirth (21 and 28%) in women with spontaneous delivery or vacuum extraction. No new symptoms occurred after c-section. There was no significant difference between the bladder neck position before and after delivery. The mobility of the bladder neck was significantly higher after vaginal delivery using a vacuum extraction compared to spontaneous delivery or c-section.

The bladder neck in women with post partum urinary stress incontinence was significantly more mobile than in continent controls. The endoanal ultrasound detected seven occult sphincter defects without any correlation to symptoms of anal incontinence.

Conclusion

Several statistically significant changes of the pelvic floor after delivery were demonstrated. Spontaneous vaginal delivery or vacuum extraction increases the risk for stress or anal incontinence, delivery with vacuum extraction leads to higher bladder neck mobility and stress incontinent women have more mobile bladder necks than continent women.