SECTION IV. OTHER
VII. AFTER PELVIC FLOOR INJURY: MANAGING THE NEXT PREGNANCY
After childbirth has resulted in pelvic floor dysfunction, appropriate guidelines for managing the next pregnancy and delivery are often unclear. Perineal injuries represent one concern; although they are most common during a woman’s first vaginal birth, “repeat” injuries can occur during subsequent deliveries. Women with a history of severe perineal laceration during their first delivery are up to 3.4 times likely to suffer a repeat injury in their next delivery (153). The same study indicated the highest risk among women undergoing forceps, vacuum, or repeat episiotomy in their second delivery—around one in five in this group—suffered a second severe perineal injury. Perineal massage during pregnancy and labor, attention to fetal size and position, and avoiding episiotomy and operative delivery whenever possible, appear to be the most effective strategies whether it is a woman’s first childbirth or a subsequent one (154).
For pelvic prolapse following childbirth, there is no evidence suggesting that operative intervention should be routinely considered. Pudendal nerve injury can accumulation with later deliveries and presumably “set the stage” for the progression of prolapse, but it is unclear whether specific obstetrical interventions can help to counteract the progression of these changes. Patients should focus on symptom relief, consider the use of a pessary, and avoid strenuous activity until later in pregnancy. By 18 – 20 weeks, as the gravid uterus rises above the pelvic brim, prolapse symptoms will often improve for the remainder of pregnancy. Likewise, there is no clear evidence to support the use of elective cesarean section for parous women already affected by urinary incontinence. After previous stress incontinence surgery, elective cesarean for subsequent deliveries has been suggested to reduce the risk of recurrence (155), but
controlled trials are lacking. The risks and benefits need to be strongly considered for each individual.
The management of childbirth after anal sphincter injuries represents another area of debate. Ultrasonography demonstrates that occult anal sphincter injuries can occur during second deliveries (156) and that the risk of anal incontinence increases, particularly among women with a sphincter defect diagnosed after the first delivery (157). Thus, although the first childbirth appears to be most important, postobstetrical pelvic floor injury can accumulate, with subsequent deliveries potentially causing new symptoms to arise, old ones to recur, or existing ones to worsen. A 1999 study (158) observed a cohort of Irish women experiencing some degree of fecal incontinence after their first vaginal birth. Nearly all of those who remained symptomatic at the time of their next pregnancy noticed that symptoms became more severe following that next second pregnancy, the second birth still led to recurrence 40% of the time.
Pudendal nerve latency was significantly longer after second delivery in this cohort, a finding corroborated by other studies (159).
Strategies for preventing repeat injury vary widely, with some experts suggesting that event women with postpartum anal incontinence should be offered cesarean delivery since a loss of bowel control is arguably one of childbirth’s most distressing repercussions. According to survey data, up to 71% of colorectal surgeons would advise women with previous anal injuries to deliver by cesarean, versus only 22% of obstetricians. Because a broad strategy of cesarean delivery is not feasible, the identification of risk factors for injury is important. For instance, in the setting of macrosomia diagnosed by prenatal ultrasound, elective cesarean delivery may represent a sound strategy both medically and economically for the prevention of anal incontinence. The use of episiotomy in the setting of a previously repaired anal sphincter is another area of debate—recommended by only 1% of colorectal surgeons, compared with up to 30% of obstetricians. Future research will hopefully result in a broader consensus regarding the best preventive obstetrical approach.
VIII. CONCLUSIONS
Pelvic floor dysfunction among postreproductive women has emerged as a major area of interest in the realm of clinical practice and research. Our awareness of the numerous underlying pathophysiologic mechanisms continues to increase, including neuropathic change and anatomic alterations to muscular and connective tissue anatomy. A variety of procedures and events during labor and delivery, including episiotomy and operative delivery, may have implications for pelvic function afterward. These and other obstetrical practices should be weighed against their potential long-term effects on the maternal pelvic floor. As future research further clarifies the most significant determinants of obstetrical pelvic floor injury, efforts at prevention will undoubtedly improve.
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