Effects of Pregnancy & Delivery on Pelvic Floor

Transcription

1 Effects of Pregnancy & Delivery on Pelvic Floor 吳 銘 斌 M.D., Ph.D. 財 團 法 人 奇 美 醫 院 婦 產 部 婦 女 泌 尿 暨 骨 盆 醫 學 科 ; 台 北 醫 學 大 學 醫 學 院 婦 產 學 科 ;

2 古 都 府 城 台 南

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4 Introduction Pelvic floor disorders (PFDs) include urinary and fecal incontinence, pelvic organ prolapse (POP). 1/3 of adult women in the US were affected. One study of 149,554 adult women reported 11% risk of undergoing a single operation for PFDs or incontinence by age 80 29% of these women required multiple surgeries. [Olsen AL 1997 Obstet Gynecol] Many other women have mild symptoms, which are managed conservatively with pessaries, pads, or no therapy.

5 Abrams et al Clinical Manual of Incontinence

6 Obstetric Factors Pregnancy: Common among pregnant women Self-limiting 28% (8 to 85%) stress incontinence [Viktrup 2001 AJOG] 16% became free of symptoms in the puerperium A predictor of post partum incontinence and a risk factor for incontinence at five years post delivery Abrams et al Clinical Manual of Incontinence

7 Obstetric Factors Childbirth: Vaginal delivery: Predispose more than cesarean section weaken or damage the pelvic floor structures and innervation to the urethral sphincter Episiotomy and instrumental delivery: 1.5x compared to spontaneous delivery 3.1x compared to Caesarean section Infant's birth weight: over 4 kg Vesico-vaginal fistula: obstetric trauma Abrams et al Clinical Manual of Incontinence

8 Obstetric Factors Parity: 1st child Four or more children Age: A strong effect modifier Young women: strongly associated aged 45 to 50 years: only modest associated Abrams et al Clinical Manual of Incontinence

9 Association of PFD with pregnancy and childbirth PFDs are more prevalent among women who have delivered at least one child: Among twins, parous sisters with at least 2 births as compared to their nulliparous twin sisters 3 times fecal incontinence (FI) [Abramov Obstet Gynecol 2005], 4 times urinary incontinence (UI) [Goldberg AJOG 2005]

10 Association of PFD with pregnancy and childbirth Premenopausal women, parous women have a higher prevalence of stress urinary incontinence (SUI) and urinary urgency. Postmenopausal women, a history of pregnancy and childbirth has little impact on the prevalence of urinary incontinence.

11 Prevalence of PFD in pregnant and postpartum women Both urinary and fecal incontinence are more common during pregnancy than before pregnancy. urinary incontinence 7 to 60 %, fecal incontinence 6 %. A survey of over 5,000 primiparous women who were continent before pregnancy, 36% leaked urine either during or after pregnancy, 19% leaked only during pregnancy; 10% leaked only after delivery: 7% leaked both [Boyles SH Obstet Gynecol 2009]. The prevalence and severity of incontinence increase throughout pregnancy, reaching a peak in the 3rd trimester [Viktrup 2001 AJOG][Van Brummen NU 2006].

12 Prevalence of PFD in pregnant and postpartum women 70% of these women spontaneously resolve postpartum [Viktrup 2001 AJOG] Within 1 year postpartum, drops to 11~23%. Among women with persistent incontinence, severity and frequency declines in the first year after childbirth A history of incontinence prior to pregnancy significantly increases the chance of persisted postpartum incontinence. POPQ stage increases during pregnancy.

13 Vaginal delivery and Pelvic Floor Pelvis anatomy

14 Mechanism for pregnancy and childbirth related PFD Neural injury Risk factors: operative delivery, prolonged 2nd stage, and high birth weight Anal sphincter disruption Major risk factor for anal incontinence Injury to the levator ani and coccygeus muscles Forceps delivery, prolonged 2nd stage of labor, and episiotomy Mediolateral episiotomy causes iatrogenic trauma

15 Can obstetrical care be modified to reduce PFD? Plan 1: Cesarean delivery before labor? Plan 2: Changes in labor management? Plan 3: Prophylactic pelvic muscle exercises? Plan 4: Limiting parity? Plan 5: Other strategies?

16 Plan 1: Cesarean delivery before labor? Prophylactic benefits of cesarean: controversial Observational studies suggested that cesarean delivery is associated with a lower rate of future UI vaginal delivery. Cesarean section reduced the risk of postpartum SUI Review [Press JZ 2007 Birth] From 16 to 9.8 % (OR = 0.56 [0.45, 0.68], number needed to prevent = 15 [12,22]) in 6 cross-sectional studies From 22 to 10 % in 12 cohort studies (OR=0.48 [0.39, 0.58], number needed to prevent = 10 [8,13]). Differences persisted by parity and after exclusion of instrumental delivery, but risk of severe SUI and UUI did not differ by mode of birth.

17 Plan 1: Cesarean delivery before labor? cesarean delivery prior to labor did not prevent incident UI after delivery [Borello-France 2006 Obstet Gynecol]. A cohort study of primiparous women (n= 124) UI 22.9% 6 months after cesarean before the onset of labor less than 1% recalled urinary incontinence prior to childbirth. the rates of UI and FI at 2 years postpartum were not significantly different [Hannah 2004 AJOG] Breech presentation; The best available data UI: 17.8 and 21.8%, RR 0.81 (95%CI ) FI: 2.4 and 2.2% RR 1.10 (95%CI ) Almost 50 % planned VB group delivered by cesarean

18 Plan 1: Cesarean delivery before labor? A 2006 NIH expert panel [2006 Obstet Gynecol] only weak evidence to support a preventative role for elective cesarean delivery, the existing data do not adequately answer whether elective cesarean delivery can reduce the incidence of PFDs. other harms and benefits of elective cesarean delivery need to be weighed.

19 Total and primary cesarean delivery rate and vaginal birth after previous cesarean (VBAC) NIH 2006 Obstet Gynecol

20 Plan 2: Changes in labor management? Episiotomy and operative delivery have independent and significant impacts on urinary and anal incontinence after delivery associated with anal sphincter trauma, a known cause of fecal incontinence. pudendal neuropathy avoidance of episiotomy and operative vaginal delivery is the most promising interventions neuropathy Routine episiotomy : not recommended

21 Plan 3: Prophylactic pelvic muscle exercises? "Kegel" did not prevent postpartum incontinence: 3 of 4 randomized trials Antenatal pelvic floor exercises begun at GA 20 weeks a decreased rate of SUI at 3 months postpartum [Reilly 2002 BJOG], but not 8 years later [Agur 2008 BJOG]. Begun at GA 23~30 weeks with preexisting UI At 1-year follow-up, no difference [Worldringh 2007 IUG] initiated immediately after delivery 3 trials; [Dumoulin 2006 Curr Opin Obs Gyn]. 2 trials no more effective than standard postnatal care 10~12 months postpartum [Sleep 1987 ][Chiarelli 2002, 2004] 1 trial showed a benefit [Meyer 2001]

22 [Dumoulin 2006 Curr Opin Obs Gyn].

23 [Dumoulin 2006 Curr Opin Obs Gyn].

24 PFMT for prevention and treatment of urinary and faecal incontinence in antenatal and postnatal women Fifteen studies; 6181 women (3040 PFMT, 3141 controls) [Hay-SMith 2008 Cochrane Rev]. Prevention: (without prior UI) in late pregnancy (about 56% less; RR 0.44, 95% CI 0.30 to 0.65) up to six months postpartum (about 30% less; RR 0.71, 95% CI 0.52 to 0.97). Treatment: (persistent UI PP 3 months) about 20% less; RR 0.79, 95% CI 0.70 to 0.90) at PP 12 months (PFMT: pelvic floor muscle training)

25 Plan 4: Limiting parity The biggest increase in the prevalence of PFDs is associated with the first birth. Among women over 50 years old, the odds of uterine prolapse doubles after a first birth and then increases by only 10% with each additional birth

26 Plan 5: Other strategies Obstetrical factors such as parity and childbirth are important in the development of UI and POP But not the only factors Nulliparous women can experience PFDs obstetrical history is account for only 50% of UI; 75% of POP [Patel 2006 AJOG] Other strong risk factors age and race: not modifiable. Smoking, obesity, etc modifiable prevention opportunities

27 Schematic of attributable risk concept. Patel DA 2006 AJOG

28 Future directions Identifying modifiable risk factors. Clarifying the mechanisms underlying the association between childbirth and PFDs. Identifying subsets of women most likely to benefit from prevention strategies. While elective cesarean is widely perceived to be an effective prevention strategy, we need more information about the value and the relative benefits and harms of this intervention.

29 Summary & Recommendations Pregnancy and childbirth appear to be associated with an increased risk of developing pelvic floor disorders. Observational studies: small numbers of subjects, inadequate attention to potential confounders, ascertain and poor outcome measures, and incomplete follow-up. No definitive conclusion Pregnancy and delivery causes pelvic floor injury By compression, stretching, or tearing of nerve, muscle, and connective tissue.

30 Summary & Recommendations Antepartum PFMT showed benefit to prevent postpartum UI (Cochrane Reviews) Postpartum PFMT showed benefit to treat persistent postpartum UI in short term f/u. We do not suggest performing cesarean delivery to prevent PFDs or worsening of existing PFDs (Grade 2C). Midline episiotomy and operative vaginal delivery increase the risk of anal sphincter tears. This risk should be weighed against the potential benefits of these procedures.