Childbearing & the Pelvic Floor: A Review of the Literature
By:Nancy H. Sullivan, CNM, MS, FACNM
Types of pelvic floor disorders
* Pelvic pain
* Nerve damage
* Pelvic organ prolapse: cystocele, rectocele, enterocele, uterine prolapse
* Urinary incontinence: stress, urge, mixed
* Fecal incontinence
Prevalence of pelvic floor disorders
* Pelvic organ prolapse is common and is seen in 50% of parous women.
* Around 10% of women in the community undergo surgery at some time of their lives for the management of prolapse (Olsen et al.).
* Urinary and fecal incontinence are common and prevalence estimates vary from 9% of women over 15 (UK study) to 38% of women over 60 (US study).
* Studied 2070 women who sought care for UI or PFD at Kaiser Permanente, San Diego.
* Forty-six percent had undergone previous hysterectomy; ten percent had undergone previous anti-incontinence surgery; six percent had undergone previous anterior or posterior repair (or both).
* Median age of women seeking care was 61; half of women were from 30-60 years of age.
* Genuine stress incontinence was more common in younger patients than in older patients (78% vs 57%);
* Detrusor instability/urge incontinence was more common in older women than in younger ones (67% vs 56%);
* Mixed incontinence was common; 38% of all patients had this diagnosis.
* Pelvic organ prolapse was similar in both groups (27% vs 30%).
* Population survey in South Australia; 3010 interviews in respondent’s homes
* Prevalence of all types of incontinence in women was 35.3%.
* Pregnancy >20 weeks, regardless of mode of delivery, greatly increased the prevalence of major pelvic floor dysfunction.
* Significant increase in PFD for women with history of instrumental delivery over women with CS, but not for women with SVD over women with CS
* Other risk factors for PFD were age, obesity or increased BMI, coughing, osteoporosis, arthritis, and reduced quality of life scores.
Additional associated factors identified in the literature:
* Menopause and estrogen depletion
* However – HRT increases the risk of developing urinary incontinence in post-menopausal women, according to new data from the Nurses’ Health Study (Grodstein et al, 2004) and from the Australian Longitudinal Study of Women’s Health (Miller et al, 2003).
* This increased risk does not vary by route of administration, type of hormone, or dose taken, but is diminished upon cessation of use.
* Depression; individuals with UI more likely to be depressed- which comes first?
* Impaired mobility; relationship among UI, urinary urgency, and falling – which comes first?
* Medications, bladder irritants
* Smoking – possibly because of smoker’s cough?
* Work environment, including limited access to bathroom, heavy lifting, bending, walking, or standing.
* Chronic disease causing cognitive impairment, peripheral neuropathy or decreased mobility. Examples are Alzheimer’s Disease, stroke Parkinson’s Disease, diabetes, multiple sclerosis.
* Physical and occupational activity, especially high-impact exercise, are risk factors.
* But…there is evidence that women who have better ability to absorb impact forces (more flexibility) have less stress incontinence.
* Nygaard et al (1996) studied the relationship between urinary incontinence in elite nulliparous athletes and force absorption as assessed by foot arch flexibility, and found a significant correlation between decreased foot flexibility and stress urinary incontinence.
Childbearing is a leading cause of pelvic floor disorders.
* Research studies are heterogeneous in definition and design, controversial, and inconclusive.
* Pregnancy itself, regardless of mode of delivery, is a risk factor. However, much of the professional as well as the lay literature ignores or minimizes this and focuses the blame on the birth process.
* Significant confounding factors are age and hysterectomy; by around 60 years of age, nulliparous women have the same rate of incontinence as parous women.
* However, most studies show an increased risk with vaginal delivery or cesarean after trial of labor over elective cesarean.
* Survey by the authors reported that 61% of women in a Dublin population (n=7771) reported the onset of symptoms of urinary incontinence before or during pregnancy.
* In another study, the authors compared two groups of healthy physio-therapists, 20-28 years, one nulliparous (n=10)and one primiparous (VD only) (n=10).
* Each group was assessed with a manual digital exam, electromyography (EMG) and perineometry on one occasion only.
* Statistical analysis of digital assessment data showed significant differences between groups for all four types of assessment, with the nulliparous group scoring higher.
* Despite measured loss of pelvic floor integrity in primiparous group, none of the subjects had symptoms of urinary incontinence.
* Authors suggest program of pelvic floor exercises for all women postpartum.
Urinary incontinence after vaginal delivery or Cesarean section
* Did not investigate the effect of instrument-assisted deliveries, shown to be a major factor in other studies
* Did not look at length of second stage or pushing phase
* Found no significant difference between rate in elective CS and CS after labor, shown to be a factor in other studies
* Found no association of incontinence with mode of delivery for women over 50, consistent with other studies
* Mean age of nulliparae lowest, women who had a vaginal birth highest
* Gestational age and birthweight significantly higher in vaginally-delivered group than in cesarean group
* Concluded that an individual woman’s risk of moderate or severe incontinence would be decreased from about 10% to about 5% if she delivered all her children by CS. This decrease would apply only until 50 years of age.
* For women having had two CS, odds still lower than for women with a VD; however, by third CS, odds were the same.
* Women who performed daily antenatal pelvic floor exercises had lower rate than those who did not; women with higher BMI and parity of 5 or greater had higher rates.
The case against elective cesarean section.
* Medial episiotomy increases anal tears (up to 22-fold in one study).
* Even without extending, episiotomy is associated with 2.4 times more fecal incontinence than spontaneous second-degree lacerations.
* Three months after childbirth, primiparae with intact perineums had the strongest pelvic floors, followed by women with spontaneous tears, women with episiotomies, and, weakest of all, women whose episiotomy extended.
* Compared with nulliparity, pelvic floor dysfunction is significantly associated with cesarean section (OR 2.5), with spontaneous vaginal delivery (OR 3.4) and with at least one instrumental delivery (OR 4.3). The difference between cesarean and instrumental delivery was significant, but not the difference between CS and VD.
* Looked at elective CS vs SVD vs CS performed for obstructed labor
* Study population 363 primiparae delivering in maternity ward in Tel Aviv; interviewed them one year postpartum regarding symptoms of SUI; excluded those with SUI prior to childbirth
* Subgroups comparable with respect to age, weight/height, gestational age at delivery, Apgar scores, and use of epidural anesthesia
* Women with postpartum SUI significantly heavier, older, and had increased prevalence of SUI during pregnancy; duration of first and second stage of labor significantly longer in these women.
* Aim of study was to quantify the changes that occur in the levator ani muscles after vaginal delivery using MRI.
* Scanned 6 women one day, one, two and six weeks, and six months postpartum
* Changes noted at one day postpartum had completely returned to normal by 6 weeks postpartum in 5 out of six women, and on one side in the sixth.
* Timing of sampling is very important.
* Vaginal delivery leads to increased anterior vaginal wall mobility.
* These alterations are more marked in women with limited pelvic organ mobility prior to childbirth.
* Postpartum sampling varied from 2-5 months, a variation of 3 months during which substantial changes may be happening.
* Current advanced imaging studies can delineate clearly the musculo-fascial defects associated with vaginal birth and could enhance our understanding of post-cesarean incontinence.
* Incidence of anal incontinence similar in primiparae with elective CS and non-instrumental VD; higher in primiparae with forceps delivery; SUI more frequent after all VD than after CS.
* Prevalence of both increases with parity, but the association with UI is lost in the elderly (hence, study showing elderly nuns with SUI).
* Postpartum urinary incontinence can persist, resolve spontaneously, or symptoms can arise de novo within a 7-year period. Primagravidae who develop incontinence in the immediate postpartum period usually regain continence within three months.
Pelvic floor exercises – Can they prevent PFD? Review of the evidence.
prevents urinary incontinence during pregnancy and after childbirth.”
* 268 primigravidae with bladder neck mobility of >5mm randomized to (1)supervised PFE with PT from 20 weeks until delivery or (2) usual advice from midwives.
* Fewer women in study group reported postpartum SUI. No difference in bladder neck mobility or in pelvic floor strength.
* Difference attributed to “the knack” of contracting pelvic floor muscles prior to exertion, cough, sneeze, etc.
What else can we learn from the literature?
Counseling Women About Elective Cesarean Section
Childbearing & the Pelvic Floor.ppt
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