Colm O'Herlihy

Effect of second vaginal delivery on anorectal physiology and faecal continence: a prospective study.

BACKGROUND Because obstetric injury to the anal sphincters may be occult, and because the mechanism of injury differs between first and subsequent deliveries, we prospectively assessed the effects of first and second vaginal deliveries on anal physiology and continence. METHODS We undertook a prospective observational study of 59 previously nulliparous women through two successive vaginal deliveries by means of a bowel-function questionnaire, and an anorectal-physiology assessment, both antepartum and 6-12 weeks post partum. FINDINGS 13 (22%) women reported altered faecal continence after their first vaginal delivery: eight had persistent symptoms during their second pregnancy, of whom seven deteriorated after the second delivery; five regained continence before their second pregnancy, but two became incontinent again after the second delivery. Five women developed incontinence for the first time after their second vaginal delivery, of whom three had occult primiparous sphincter injury. 20 (34%) women, seven of whom had no symptoms, had anal-sphincter injury as a result of their first delivery, but only two new injuries occurred after the second vaginal delivery (p=0.013). Although pudendal neuropathy was no more common after the second than after the first vaginal delivery (15 vs 19%, p=0.8), pudendal-nerve latency was longer after the second delivery (p=0.02). INTERPRETATION Primiparous women with persistent symptoms of altered faecal continence experience deterioration after a second vaginal delivery. Women with transient faecal incontinence or occult anal-sphincter injury after their first vaginal delivery are at high risk of faecal incontinence after a second vaginal delivery. The risk of mechanical anal sphincter injury is greatest after the first delivery.

Influence of persistent occiput posterior position on delivery outcome

OBJECTIVE To evaluate the influence of intrapartum persistent occiput posterior position of the fetal head on delivery outcome and anal sphincter injury, with reference to the association with epidural analgesia. METHODS We conducted a prospective observational study of 246 women with persistent occiput posterior position in labor during a 2‐year period, compared with 13,543 contemporaneous vaginal deliveries with occiput anterior position. RESULTS The incidence of persistent occiput posterior position was significantly greater among primiparas (2.4%) than multiparas (1.3%; P < .001; 95% confidence interval 1.4, 2.4) and was associated with significantly higher incidences of prolonged pregnancy, induction of labor, oxytocin augmentation of labor, epidural use, and prolonged labor. Only 29% of primiparas and 55% of multiparas with persistent occiput posterior position achieved spontaneous vaginal delivery, and the malposition was associated with 12% of all cesarean deliveries performed because of dystocia. Persistent occiput posterior position was also associated with a sevenfold higher incidence of anal sphincter disruption. Despite a high overall incidence of use of epidural analgesia (47% versus 3%), the institutional incidence of persistent occiput posterior position was lower than that reported 25 years ago. CONCLUSION Persistent occiput posterior position contributed disproportionately to cesarean and instrumental delivery, with fewer than half of the occiput posterior labors ending in spontaneous delivery and the position accounting for 12% of all cesarean deliveries for dystocia. Persistent occiput posterior position leads to a sevenfold increase in the incidence of anal sphincter injury. Use of epidural analgesia was not related to the malposition.

Comparative analysis of international cesarean delivery rates using 10-group classification identifies significant variation in spontaneous labor.

OBJECTIVE Cesarean section (CS) rates continue to rise throughout the developed world. The aim of this study was to highlight variations in obstetric populations and practices and to identify variations in CS rates in different institutions. STUDY DESIGN Data from 9 institutional cohorts (total, 47,402; range, 1962-7985) from 9 different countries were examined using a 10-group classification system based on 4 characteristics of every pregnancy, namely single/multiple, nulliparity/multiparity, multiparity with CS scar, spontaneous/induced labor onset and term (>or=37 weeks) gestation. RESULTS Overall CS rates correlated with CS rates in singleton cephalic nullipara (r = 0.992; P < .001). Whereas CS rates in induced labor were similar, greatest institutional variation were seen in spontaneously laboring multiparas (6.7-fold difference) and nulliparas (3.7-fold difference). CONCLUSION Ten-group analysis of international obstetric cesarean practice identifies wide variations in women in spontaneous cephalic term labor, a low-risk cohort amenable to effective intrapartum corrective intervention.

Cesarean delivery and anal sphincter injury

Objective Cesarean delivery has been thought to prevent all obstetric anal sphincter damage. The objective of this study was to determine the relationship between the timing of cesarean during primiparous delivery and injury to the anal sphincter mechanism. Methods A prospective observational study was conducted, using a continence questionnaire and anorectal physiology assessment before and six weeks after primiparous delivery. A cohort of 234 women were recruited from the antenatal clinics at the National Maternity Hospital, Dublin. Thirty-four women delivered subsequently by cesarean, and 200 women by spontaneous vaginal delivery. Results Thirty-four women underwent cesarean delivery without attempted vaginal delivery: eight prior to labor and 26 during labor, 17 in early labor (cervical dilatation less than 8 cm) and 9 in late labor (dilatation greater than 8 cm). No woman delivered by cesarean had altered fecal continence postpartum. Anorectal physiology was unaltered in women delivered by elective cesarean or cesarean in early labor. Pudendal nerve terminal motor latency was prolonged, anal squeeze pressure increment reduced, but vector symmetry index was unchanged in women delivered by cesarean delivery late in labor, indicating neurologic injury to the anal sphincter mechanism. Conclusion Cesarean delivery performed in late labor, even in the absence of attempted vaginal delivery, does not protect the anal sphincter mechanism.

A prospective, randomized study comparing the effect of augmented biofeedback with sensory biofeedback alone on fecal incontinence after obstetric trauma

PURPOSE: This study was designed to compare prospectively the effects of augmented biofeedback with those of sensory biofeedback alone on fecal incontinence and anorectal manometry after obstetric trauma. METHODS: A consecutive cohort of 40 females with impaired fecal continence after obstetric anal sphincter injury were recruited from a dedicated perineal clinic. Patients were randomly assigned to receive either augmented biofeedback or sensory biofeedback alone. All patients were assessed before and after twelve weeks of biofeedback training, using a fecal continence questionnaire and anorectal manometry. RESULTS: Thirty-nine of 40 females recruited completed the study. Continence scores improved in both treatment groups, but the results were better for those who received augmented biofeedback. Anorectal manometry was unchanged by sensory biofeedback, whereas anal resting and squeeze pressures increased with augmented biofeedback. No change in anal vector symmetry was observed in either group. CONCLUSION: Augmented biofeedback training is superior to sensory biofeedback alone in the treatment of impaired fecal continence after obstetric trauma.

The value of ultrasound measurement of amniotic fluid ume in the management of prolonged pregnancies

Ultrasound assessment of amniotic fluid ume was used to monitor 335 patients with prolonged pregnancy. Reduced amniotic fluid was diagnosed when no single vertical pool of amniotic fluid measured >30 mm. Sixty‐five patients with reduced amniotic fluid had labour induced while 270 patients with normal amniotic fluid were managed expectantly unless the cervix was favourable. Patients with reduced amniotic fluid had a statistically significant increase in meconium‐stained amniotic fluid and growth‐retarded babies and were more likely to require delivery by caesarean section for fetal distress. There were no perinatal deaths in the series and the perinatal outcome was satisfactory in both groups. Ultrasound measurement of amniotic fluid represents an effective discriminatory test in post‐term pregnancy.

Does the angle of episiotomy affect the incidence of anal sphincter injury

Objective  Mediolateral episiotomy is associated with lower rates of significant perineal tears than midline episiotomy. However, the relationship between precise angle of episiotomy from the perineal midline and risk of third‐degree tear has not been established. This study quantifies this relationship.

Singleton vaginal breech delivery at term: still a safe option.

OBJECTIVE: To examine the obstetric and perinatal outcome of pregnancies with singleton breech presentation at term when selection for vaginal delivery was based on clear prelabor and intrapartum criteria. METHODS: The outcomes of all pregnancies with a breech presentation after 37 weeks of gestation were retrospectively reviewed from January 1997 to June 2000. Criteria for prelabor cesarean or trial of vaginal breech delivery included type of breech, estimated fetal weight (more than 3,800 g), maternal preference, and gestation more than 41 weeks. An intrapartum protocol excluded induction and oxytocin augmentation of labor, combined with a low threshold for cesarean delivery for dystocic labor; an experienced obstetrician was in attendance during labor and delivery. RESULTS: Of 641 women, 343 (54%) underwent prelabor cesarean, and 298 (46%) had a trial of vaginal delivery, of whom 146 (49%) delivered vaginally. Significantly fewer nulliparas (58 of 158, 37%) than multiparas (88 of 140, 63%; P < .001) achieved vaginal delivery after trial of labor. Significantly more infants weighing more than 3,800 g were selected for prelabor (87 of 343, 25%) and intrapartum (31 of 152, 20%) cesarean than delivered vaginally (15 of 146, 10%). Two neonates (0.7%) had Apgar scores of less than 7 at 5 minutes; both were neurologically normal at 6 weeks. There were no nonanomalous perinatal deaths and no cases of significant trauma or neurological dysfunction; 3 infants delivered vaginally died due to lethal anomalies. CONCLUSION: Safe vaginal breech delivery at term can be achieved with strict selection criteria, adherence to a careful intrapartum protocol, and with an experienced obstetrician in attendance. Our protocol effectively selects larger infants for cesarean delivery. LEVEL OF EVIDENCE: II-2

The influence of oestrogen replacement on faecal incontinence in postmenopausal women

Objective To assess the value of hormone replacement therapy (HRT) in postmenopausal women with faecal incontinence.

Randomised clinical trial to assess anal sphincter function following forceps or vacuum assisted vaginal delivery

Objective To compare, in a prospective, randomised controlled trial, differences in anal sphincter function following forceps or vacuum assisted vaginal delivery in an institution practising standardised management of labour.