Joshi AV*, Pradhan M**, Gupta AS***
(* Specialty Medical Officer, ** First Year resident, **Professor. Department of Obstetrics and Gynecology, Seth GS Medical College and KEM Hospital, Mumbai, India.)
Obstetric anal sphincter injuries (OASIs) are a severe form of perineal lacerations commonly encountered with difficult vaginal deliveries. They can severely affect the patient’s daily routine and quality of life. This case report highlights the management dilemma that an obstetrician encounters in a patient with a deficient perineal body, sustained during previous vaginal birth.
The incidence of obstetric anal sphincter injuries following a vaginal delivery is presently around 3-4%. These can predispose the patients to long term morbidities like dysparenuia, fecal or urinary incontinence, pelvic organ prolapse etc. A term patient managed elsewhere who presented in active labour is described here.
A 22 year old G2P1L0A0 at 40 weeks of gestation was referred in view of meconium stained amniotic fluid. Referral note also mentioned high risk factor of “deficient perineal body”. She was antenatally registered at a private hospital in this pregnancy at 5th month of gestation. She had two antenatal visits, antenatal profile was normal. She does not give history of any bowel or bladder complaints in the antenatal period.
The first delivery outcome was a neonatal death that occurred 2 years back. It was a full term vaginal delivery at a primary health center with a birth weight of 4.5 kg. Baby did not cry at birth and died in transit to a higher center for want of NICU care. She complained of symptoms like fecal urgency, inability to control flatus and fecal incontinence in the immediate postpartum period. However, since the symptomatology significantly improved, she did not follow up for these complaints. Upon questioning, she reported that she gradually achieved fecal continence by 6 months post-delivery without any active interventions.
On examination, vital parameters were stable. Uterus was full-term, vertex (2/5th palpable) with an activity of 3/10/30. Fetal heart sounds were 120 beats per minute with persistent variable decelerations till 80 beats per minute. On per vaginal examination cervix was fully dilated, fully effaced, station at zero, occiput at 3’0 clock with presence of caput and liquor was meconium stained. On local examination, perineal body was absent. There was a thin band of fibrous tissue formed by the posterior vaginal wall and torn external anal sphincter suggestive of an old third-degree tear. A decision for emergency lower segment cesarean section was taken in view of severe fetal distress in second stage of labor. Instrumental delivery was not done as station was at zero. She delivered a male child of 3.6 kg.
She required a cesarean section in this pregnancy for a fetal indication. Surprisingly, she remained asymptomatic following this childbirth. We had planned for a repair of the deficient perineal body after her puerperium, however she was reluctant since she was asymptomatic.
Figure 1: Image showing an old third degree perineal tear with arrow pointing towards area of fibrosis
The perineal body is a fibromuscular structure that provides strength to the pelvic floor. It is the junction formed by the following muscles: external anal sphincter, bulbospongiosus muscle, superficial and deep transverse perineal muscles, anterior fibers of levator ani and the external urinary sphincter. Perineal injuries are classified into four degrees of tear. Injuries to the perineal body are generally categorized into grade three which are further subdivided depending upon the degree of involvement of the external or internal anal sphincter. Obstetric anal sphincter injuries primarily refer to the third and fourth degree perineal lacerations which involve the anal sphincter and rectal mucosa respectively.
The risk factors for such injuries include young primipara, induction of labour, advanced gestational age, obesity, operative vaginal delivery and infant birth weight >3500 grams. The clinical presentation of the patient depends upon the degree of neuromuscular and connective tissue damage. These include urinary and/ or anal incontinence, anal incontinence being more common. Anal incontinence can further be categorized as inability to control flatus, fecal urgency or fecal incontinence.
The long term morbidities associated with such injuries include chronic pelvic pain, dyspareunia, pelvic organ prolapse, rectovaginal fistulas and recurrence in subsequent pregnancies.
A study by Brincat et al showed an increase in fecal incontinence at 6 weeks postpartum which gradually subsided at 6 months and then again showed an increase at 1 year post-delivery. This warrants a need for close follow up in such patients despite relief of symptoms. The improvement noted at 6 months post delivery is usually a result of restoration of the neuromuscular as well as connective tissue elements of the pelvic floor. The resurfacing of symptoms at 1 year was attributed to lifestyle practices, bowel habits, diet, medications. Women with a 3rd or 4th degree perineal tear in the first vaginal delivery are at 3-4 times increased risk of experiencing a recurrent laceration in the subsequent pregnancy.
This case is being reported to highlight the interesting facts and dilemmas that crossed our minds while managing this patient. When she presented to us in the emergency room, we intended to deliver her vaginally. When she developed severe intra partum fetala distress instrumental delivery was not done as the vertex remained at station zero even when she was reassessed in the operation theater immediately prior to the cesarean section.
The first dilemma: Had the patient delivered vaginally, would an episiotomy be required? Technically, considering the absence of the perineal body, there would have been no resistance offered from the pelvic floor. Hence there is no role of a prophylactic episiotomy in this case. However, the requirement of episiotomy should be individualized. Evidence in this matter is lacking.
The next challenge would have been in the event of a laceration being sustained while delivering her vaginally. Do such patients need an immediate repair of the tear? Or is surgical repair after 6 weeks preferred? Again, literature in this subject is lacking. Every case must be individualized and managed as per the treating doctor’s clinical acumen. Immediate repair of such injuries carry a risk of fecal contamination and breakdown of the wound as bowel preparation is not done in spontaneous labors. Repair immediate post delivery would entail application of surgical principles for a complete perineal repair in a gynecological patient. Pre existing fibrous excision would be needed prior to the layered repair. As the bowel preparation is not done in spontaneous labors fecal contamination will occur. When such patients present in latent labor, bowel preparation may be possible to enable immediate repair post delivery. The mode of delivery in these patients in subsequent pregnancies remains a challenge due to lack of robust evidence. Additional factors like history of failure of previous repair, persistent anal incontinence and larger estimated birth weight of the fetus may go in favor of an elective cesarean section. However, the risk of recurrence of a perineal tear with instrumental delivery or greater birth weight in subsequent pregnancies for such patients was lesser, possibly due to the stretching of perineum in previous pregnancy. In well-equipped centers an anal manometry can further guide to decide the mode of delivery. Asymptomatic patients can undergo a vaginal delivery in presence of a skilled obstetrician.
The primary approach to a patient with deficient perineal body depends on the nature and severity of her symptoms and the time of presentation. The mode of delivery in these patients remains controversial. A decision for the same, must be made after a thorough clinical examination and if possible an anal manometry. Patients must be made aware of the associated complications with any mode of delivery and an informed consent must be obtained for the same. Timely detection and repair of perineal injuries is vital to ensure a good quality of life.
- Friedman AM, Ananth CV, Prendergast E, D'Alton ME, Wright JD. Evaluation of third-degree and fourth-degree laceration rates as quality indicators. Obstet Gynecol. 2015 Apr;125(4):927-37
- Brincat C, Lewicky-Gaupp C, Patel D, Sampselle C, Miller J, Delancey JOL, et al. Brincat C, Lewicky-Gaupp C, Patel D, Sampselle C, Miller J, Delancey JOL, et al. Fecal incontinence in pregnancy and postpartum. Int J Gynaecol Obstet. 2009;106(3):236–8.
- Lowder JL, Burrows LJ, Krohn MA, Weber AM. Risk factors for primary and subsequent anal sphincter lacerations: a comparison of cohorts by parity and prior mode of delivery. Am J Obstet Gynecol 2007;196(4): 344.e1-5.
- Edozien LC, Gurol-Urganci I, Cromwell DA, Adams EJ, Richmond DH, Mahmood TA, et al. Impact of third- and fourth-degree perineal tears at first birth on subsequent pregnancy outcomes: A cohort study. BJOG. 2014;121(13):1695–703.
Joshi AV, Pradhan M, Gupta AS. Obstetric Challenges With Previous Unrepaired Third Degree Perineal Tear. JPGO 2017. Volume 4 No.12. Available from: http://www.jpgo.org/2017/12/obstetric-challenges-with-previous.html