Impact of Episiotomy During Operative Vaginal Delivery on Obstetrical Anal Sphincter Injuries

ObjectiveThe purpose of this study was to describe associations between episiotomy at the time of forceps or vacuum-assisted delivery and obstetrical anal sphincter injuries (OASIS).MethodsThis population-based retrospective cohort study used delivery information from a provincial perinatal clinical database. Full-term, singleton, in-hospital, operative vaginal deliveries of vertex-presenting infants from April 1, 2006 to March 31, 2016 were identified. Odds ratios (ORs) and 95% confidence intervals (CIs) for associations between episiotomy and third- or fourth-degree lacerations were calculated in multiple logistic regression models (Canadian Task Force Classification II-2).ResultsEpisiotomy was performed in 34% of 52 241 operative vaginal deliveries. OASIS occurred in 21% of forceps deliveries and 7.6% of vacuum deliveries. Episiotomy was associated with increased odds of severe perineal lacerations for vacuum deliveries among women with (OR 2.48; 95% CI 1.96–3.13) and without (OR 1.12; 95% CI 1.02–1.22) a prior vaginal delivery. Among forceps deliveries, episiotomy was associated with increased odds of OASIS for those with a previous vaginal delivery (OR 1.52; 95% CI 1.12–2.06), but it was protective for women with no previous vaginal delivery (OR 0.73; 95% CI 0.67–0.79). Midline compared with mediolateral episiotomy increased the odds of OASIS in forceps deliveries (OR 2.73; 95% CI 2.37–3.13) and vacuum deliveries (OR 1.94; 95% CI 1.65–2.28).ConclusionIn conclusion, results suggest that episiotomy should be used with caution, particularly among women with a previous vaginal delivery and in the setting of vacuum-assisted delivery. Episiotomy may protect against OASIS in forceps-assisted deliveries for women without a prior vaginal delivery.     

Risk factors for birth canal lacerations in primiparous women

Lacerations of the birth canal are common side effects of vaginal birth. They are potentially preventable. Although serious long-term consequences have been identified for severe perineal lacerations, less attention has been paid to lacerations in other locations and how the risk factors vary for different lacerations. We analyzed a dataset including 1009 primiparous women with singleton pregnancies and vaginal deliveries, and we examined risk factors for third- and fourth-degree perineal lacerations and periurethral, vaginal, and labial lacerations using logistic regression analysis. Large fetal size (> or = 3500 g) substantially increased the risk of perineal (odd ratio [OR], 3.8; 95% confidence interval [CI], 1.8 to 7.9) and periurethral (OR, 2.3; 95% CI, 1.0 to 5.0) lacerations but not other types of lacerations. Episiotomy had no impact on perineal lacerations (OR 0.9) but had very strong protective effects for other lacerations (OR 0.1). Prolonged second stage of labor (> 120 minutes) increased the risk of perineal and vaginal lacerations but reduced the risk for periurethral lacerations. Instrumental deliveries were significant risk factors for third- and fourth-degree perineal lacerations, with by far the strongest effect for low forceps (OR 25.0 versus < 3 for outlet forceps, outlet vacuum, and low vacuum). We concluded that separating different birth canal lacerations is critical in identifying risk factors and potential preventive strategies.     

Risk of new-onset urinary incontinence after forceps and vacuum delivery in primiparous women

OBJECTIVE: We sought to determine the incidence of new-onset urinary incontinence after forceps and vacuum delivery compared with spontaneous vaginal delivery. STUDY DESIGN: We performed a prospective study in primiparous women delivered by forceps (n = 90), vacuum (n = 75), or spontaneous vaginal delivery (n = 150). Follow-up for urinary incontinence was at 2 weeks, 3 months, and 1 year after delivery. RESULTS: The incidence of urinary incontinence was similar in the 3 groups at 2 weeks after delivery. The proportion of women developing new-onset urinary incontinence decreased significantly over time in the spontaneous vaginal (P =.003) and vacuum delivery groups (P =.009) but not in the forceps group (P =.2). No relationship of urinary incontinence with vaginal lacerations, epidural anesthesia, length of second stage of labor, or infant birth weight was seen. CONCLUSIONS: In primiparous women, urinary incontinence after forceps delivery is more likely to persist compared with spontaneous vaginal or vacuum delivery.     

Maternal and neonatal morbidity in instrumental deliveries with the Kobayashi vacuum extractor and low forceps

Risks to the mother and newborn associated with the use of the Kobayashi Silastic vacuum extractor (n = 293) were compared with those associated with the use of low forceps (n = 468) in a retrospective chart review. Third or fourth degree perineal tears and vaginal and cervical lacerations were all observed less frequently among women delivered with the vacuum extractor. The need for post-partum bladder catheterization was also reduced for these women. Babies born by the means of the vacuum extractor ran an increased risk of cephalhematoma and neonatal jaundice. No difference in major neonatal morbidity was observed between the two groups. The Kobayashi instrument appears to be a useful alternative to forceps in low vaginal instrumental deliveries.     

The effect of sequential use of vacuum and forceps for assisted vaginal delivery on neonatal and maternal outcomes

OBJECTIVE: To determine the risk of neonatal and maternal disease associated with the sequential use of vacuum and forceps compared with spontaneous vaginal delivery. STUDY DESIGN: Using Washington state birth certificate data linked to hospital discharge records, we compared 3741 vaginal deliveries by both vacuum and forceps, 3741 vacuum deliveries, and 3741 forceps deliveries to 11,223 spontaneous vaginal deliveries. RESULTS: Compared with spontaneous vaginal deliveries, deliveries by sequential use of vacuum and forceps had significantly higher rates of intracranial hemorrhage (relative risk [RR], 3.9; 95% confidence interval [CI], 1.5 to 10.1), brachial plexus (RR, 3.2; 95% CI, 1.6 to 6.4), facial nerve injury (RR, 13.3; 95% CI, 4.7 to 37.7), seizure (RR, 13.7; 95% CI, 2.1 to 88.0), depressed 5-minute Apgar score (RR, 3.0; 95% CI, 2.2 to 4.0), assisted ventilation (RR, 4.8; 95% CI, 2.1 to 11.0), fourth-degree (RR, 11.4; 95% CI, 6.4 to 20.1 among multiparous women) and other lacerations, hematoma (RR, 6.2; 95% CI, 2.1 to 18.1 among multiparous women), and postpartum hemorrhage (RR, 1.6; 95% CI, 1.3 to 2.0). The relative risk of sequential vacuum and forceps use was greater than the sum of the individual relative risks of each instrument for intracranial hemorrhage, facial nerve injury, seizure, hematoma, and perineal and vaginal lacerations. CONCLUSION: Sequential use of vacuum and forceps is associated with increased risk of both neonatal and maternal injury.     

Instrumental extraction in 2002 in the "AURORE" hospital network: incidence and serious neonatal complications

OBJECTIVES: The purpose of this study was to evaluate the incidence of forceps and vacuum application and the incidence of its related neonatal complications. This study was performed in a network of 37 maternity hospitals. PATIENTS AND METHOD: A postal questionnaire was sent to 156 obstetricians between February and March 2003. RESULTS: Response rate was 78%. In 2002 the operative vaginal delivery rate was 11.2% of all live births. Forceps are the primary instruments (6.3%) whereas vacuum delivery rate was 4.9%. One obstetrician never uses forceps while 38 (31%) never use vacuum. Only 29 (24%) report using both instruments frequently. During 2002 no neonatal death related to an operative vaginal delivery was reported while 145 neonatal complications were (3.2%). Major complications were one depressed skull fracture (1/4589) and 14 extensive caput succedaneum (14/4589). Minor complications were cutaneous lesions (124/4589) and facial palsy (6/4589). Vacuum delivery was associated with a significantly higher extensive caput succedaneum rate (P = 0.018) while the only depressed skull fracture observed was related to forceps use. Forceps delivery was associated with a significantly higher cutaneous lesions rate (P < 0.001). DISCUSSION AND CONCLUSIONS: This study showed that, in 2002, operative vaginal deliveries still represent a significant amount of vaginal deliveries, a majority of obstetricians do not use both instrument and neonatal associated complications are frequent (3.2%) but rarely severe. Therefore, we believe that every method that allows a safe teaching of operative delivery should be promoted.     

Effect of instrument preference for operative deliveries on obstetrical and neonatal outcomes

Objectives

To examine the relationship between physicians’ instrument preference and obstetrical and neonatal outcomes.

Study design

A retrospective cohort study comparing obstetrical and neonatal outcomes of second stage deliveries between obstetricians who prefer forceps (forceps ≥90%) with obstetricians with no preference to forceps (either instrument <90%) was completed using the McGill Obstetrical and Neonatal Database. Logistic regression analysis was used to obtain an adjusted odds ratio controlling for maternal, intrapartum and neonatal confounders.

Results

Two thousand and three hundred thirteen infants were delivered by 5 obstetricians who preferred forceps, and 9261 infants were delivered by 15 obstetricians with no instrument preference. Baseline characteristics were similar between the two groups. As compared to obstetricians who preferred forceps, obstetricians with no instrument preference had a higher rate of operative vaginal deliveries 1.5 (1.1–2.0), a higher cesarean section rate 2.5 (1.3–4.9) and a higher episiotomy rate in non-operative vaginal deliveries 3.4 (2.7–4.3). Infants delivered by obstetricians with no instrument preference were less likely to have significant bruising 0.3 (0.2–0.6) but more likely to have a cephalohematoma 3.0 (1.1–8.3).

Conclusion

Physician instrument preference is an important determinant of outcomes that should be considered in studies evaluating instrumental deliveries.     

Comparison of outcomes between operative vaginal deliveries and spontaneous vaginal deliveries in southeast Nigeria

Objective

To evaluate the incidence of, indications for, and outcome of operative vaginal deliveries compared with spontaneous vaginal deliveries in southeast Nigeria.

Methods

A retrospective cohort study was conducted involving cases of operative vaginal delivery performed at Ebonyi State University Teaching Hospital over a 10-year period. Data on the procedures were abstracted from the operation notes of the medical records of parturients.

Results

An incidence of 4.7% (n = 461) was recorded. The most common indications for vacuum and forceps delivery were prolonged second stage of labor (44.9%) and poor maternal effort (27.8%). The only indication for destructive operation was intrauterine fetal death (3.7%). The risk ratio (RR) for hemorrhage/vulvar hematoma was 1.14 (95% confidence interval [CI], 0.53–2.48) for vacuum-assisted delivery and 5.49 (95% CI, 0.82–36.64) for forceps delivery. The RR for genital laceration was 1.21 (95% CI, 0.44–3.30) for vacuum-assisted delivery and 9.41 (95% CI, 1.33–66.65) for forceps delivery. The risk of fetal scalp bruises and caput succedaneum was higher for operative vaginal delivery than for spontaneous vaginal delivery, with no significant difference in maternal morbidity. The perinatal mortality rate was 0.9 per 1000 live births.

Conclusion

Operative vaginal delivery by experienced healthcare providers is associated with good obstetric outcomes with minimal risk.     

Vacuum assisted delivery in Ecuador for prolonged second stage of labor: maternal-neonatal outcome.

BACKGROUND: In South America, and particularly Ecuador, cesarean section rates have risen markedly over the past five years. The associated increases in maternal morbidity and healthcare costs indicate the need for alternative strategies. Operative vaginal delivery is minimally utilized in Ecuador, as neither vacuum nor forceps have been available. OBJECTIVE: As vacuum delivery was recently introduced to our clinical service, we sought to examine our initial experiences (i.e., maternal and neonatal outcome) with operative vaginal delivery for prolonged second stage of labor. METHODS: Following an initial educational program at the Enrique C. Sotomayor Obstetrics and Gynecology Hospital, Guayaquil, Ecuador, vacuum extraction cups (Mityvac, Cooper Surgical) were offered to laboring women with term singleton gestations and cephalic presentations no higher than +3 station. Maternal and neonatal data were analyzed. RESULTS: During the study period, 100 vacuum applications were performed on laboring women complicated with prolonged second stage of labor. Mean maternal age was 23.8 +/- 6.4 years (range 14-41 years) with 57% of patients nulliparous. Left anterior and right posterior fetal positions were the most frequent (85% and 11%, respectively). Maternal complications included need for blood transfusion (1%), shoulder dystocia (1%) and perineal tears (first degree 6%, second degree 5%). Vaginal delivery was successful in 97% of cases. Among neonates, the average weight was 3149 +/- 410 g, with 10% neonates small for gestational age and 5% large for gestational age. Only 1% of infants presented an Apgar score <7 at 5 min. There were no scalp lacerations, cephalohematomas, or subgaleal bleeds. CONCLUSIONS: In this initial observational study, vacuum extraction for prolonged second stage was safe and effective. We propose that the introduction of operative vaginal delivery to developing countries will mitigate rising cesarean section rates.     

Kielland vs. nonrotational forceps for the second stage of labor.

OBJECTIVE: To examine and compare maternal and neonatal morbidity after use of two types of obstetric forceps used in the management of the second stage of labor. STUDY DESIGN: This retrospective investigation was conducted from January 1993 to December 1995 and included 55 infants delivered with Kielland forceps as compared to 213 infants delivered with nonrotational forceps. The maternal and neonatal charts were reviewed for data collection. Maternal complications compared included blood loss, vaginal lacerations, postpartum hemorrhage, and third- and fourth-degree perineal lacerations. Infant data collected compared fetal lacerations, nerve palsies, shoulder dystocias, blood gas values and admissions to the neonatal intensive care unit. Statistical analysis was performed by Fisher's exact, chi 2 and Student's t test. RESULTS: Women in both groups were similar with respect to age, gravidity, parity and estimated gestational age at delivery. Infants were similar in both groups with respect to fetal weight, admissions to the neonatal intensive care unit, nerve compromise, scalp lacerations and facial bruising. The Kielland group had statistically significantly longer labor, 671 +/- 285.8 vs. 614 +/- 226.5 minutes (P < .05) and longer second stage of labor 184 +/- 74.71 vs. 161 +/- 65.79 minutes (P < .05). The Kielland group also had a statistically higher percentage of one-minute Apgar scores < 6, 18.2% vs. 4.7% (P < .05), and meconium present at delivery, 14.5% vs. 5.6% (P < .05). CONCLUSION: Management of the second stage of labor can be accomplished safely with Kielland forceps and rotation of the fetal head. Supervision by an experienced operator will allow residents to be trained with respect to appropriate patient selection and application of these forceps.     

The midforceps: maternal and neonatal outcomes

A retrospective review of midforceps deliveries occurring between 1976 and 1982 at a county teaching hospital is presented. Midforceps deliveries were performed in 0.8% of deliveries (176 of 21,414) during this period, a rate reflecting the general admonition against potentially traumatic injury to the infant. Under these conditions, midforceps deliveries were associated with active and second-stage labor abnormalities, abnormal fetal heart rate patterns, maternal perineal lacerations, low 1-minute Apgar scores, and neonatal cephalohematomas more frequently than were deliveries of the remainder of the patients. Epidural anesthesia was significantly associated with midforceps deliveries. Midforceps patients were matched to similar groups who were delivered by cesarean section or low forceps or who had spontaneous births. The findings do not document an increase in short-term neonatal morbidity in the midforceps group under the conditions described.     

Neonatal acidosis and method of delivery

Seven hundred and four women who had a forceps termination (177 elective, 293 indicated low, and 234 indicated midforceps) of labor over 24 months were compared with 303 spontaneous and 111 cesarean deliveries over the same time period. There was no significant difference between indicated low or midforceps either for fetal distress or arrest of descent with regard to fetal acidosis (pH less than 7.20), one- or five-minute Apgar scores less than 7, fetal trauma, or neurologic deficit at discharge. Fourteen percent of indicated forceps for arrest of descent had neonatal acidosis, versus 8% of cesarean sections for cephalopelvic disproportion (P = NS), and 23% of indicated forceps for fetal distress had acidosis, versus 33% of cesarean sections (P = not significant). There was no significant difference either in the incidence of acidosis or in low Apgar scores in neonates delivered by elective low forceps compared with those born by spontaneous vaginal delivery. The only significant differences in midforceps versus low forceps were between maternal pre- and postdelivery hematocrits (P less than .0001) and vaginal lacerations (P less than .0001). The authors' data support the continued usage of indicated low and selected midforceps operations.     

Mediolateral episiotomy reduces the risk for anal sphincter injury during operative vaginal delivery

Objective  To determine the risk factors for anal sphincter injuries during operative vaginal delivery.
Setting and design  A population-based observational study.
Population  All 21 254 women delivered with vacuum extraction and 7478 women delivered with forceps, derived from the previously validated Dutch National Obstetric Database from the years 1994 to 1995.
Methods  Anal sphincter injury was defined as any injury, partial or complete, of the anal sphincters. Risk factors were determined with multivariate logistic regression analysis.
Main outcome measures  Individual obstetric factors, e.g. fetal birthweights, duration of second stage, etc.
Results  Anal sphincter injury occurred in 3.0% of vacuum extractions and in 4.7% of forceps deliveries. Primiparity, occipitoposterior position and fetal birthweight were associated with an increased risk for anal sphincter injury in both types of operative vaginal delivery, whereas duration of second stage was associated with an increased risk only in vacuum extractions. Mediolateral episiotomy protected significantly for anal sphincter damage in both vacuum extraction (OR 0.11, 95% CI 0.09–0.13) and forceps delivery (OR 0.08, 95% CI 0.07–0.11). The number of mediolateral episiotomies needed to prevent one sphincter injury in vacuum extractions was 12, whereas 5 mediolateral episiotomies could prevent one sphincter injury in forceps deliveries.
Conclusions  Primiparity and occipitoposterior presentation are strong risk factors for the occurrence of anal sphincter injury during operative vaginal delivery. The highly significant protective effect of mediolateral episiotomies in both types of operative vaginal delivery warrants the conclusions that this type of episiotomy should be used routinely during these interventions to protect the anal sphincters.     

Obstetric anal sphincter lacerations

OBJECTIVE: To estimate the frequency of obstetric anal sphincter laceration and to identify characteristics associated with this complication, including modifiable risk factors. METHODS: A population-based, retrospective study of over 2 million vaginal deliveries at California hospitals was performed, using information from birth certificates and discharge summaries for 1992 through 1997. We excluded preterm births, stillbirths, breech deliveries, and multiple gestations. The main outcome measure was obstetric anal sphincter laceration (third and fourth degree). RESULTS: The frequency of anal sphincter lacerations was 5.85% (95% confidence interval [CI] 5.82, 5.88), decreasing significantly from 6.35% (95% CI 6.27, 6.43) in 1992 to 5.43% (95% CI 5.35, 5.51) in 1997 (P <.01). Using logistic regression analysis, we identified primiparity as the dominant risk factor (odds ratio [OR] for women with prior vaginal birth 0.15; 95% CI 0.14, 0.15). Birth weight over 4000 g was also highly significant (OR 2.17; 95% CI 2.07, 2.27). Lacerations occurred more often among women of certain racial and ethnic groups: Indian women (OR 2.5; 95% CI 2.23, 2.79) and Filipina women (OR 1.63; 95% CI 1.50, 1.77) were at highest risk. Episiotomy decreased the likelihood of third-degree lacerations (OR 0.81; 95% CI 0.78, 0.85), but increased the risk of fourth-degree lacerations (OR 1.12; 95% CI 1.05, 1.19). Operative delivery increased the risk of sphincter laceration, with vacuum delivery (OR 2.30; 95% CI 2.21, 2.40) presenting a greater risk than forceps delivery (OR 1.45; 95% CI 1.37, 1.52). CONCLUSION: Anal sphincter lacerations are strongly associated with primiparity, macrosomia, and operative vaginal delivery. Of the modifiable risk factors, operative vaginal delivery remains the dominant independent variable.     

Temporal trends and morbidities of vacuum,forceps, and combined use of both

Abstract

Objective: To assess trends over time of operative vaginal delivery and compare delivery-related morbidity between vacuum delivery, forceps delivery, or combined use of both in California.

Methods: California ICD-9 discharge data from 2001 to 2007 were used to identify cases of forceps and vacuum delivery.

Results: There was a decline in all operative delivery types (9.0% in 2001 to 7.6% in 2007), with the decline in the use of forceps most pronounced (7.26/1000 deliveries in 2001 to 3.85/1000 in 2007). Higher rates of third/fourth degree lacerations, postpartum hemorrhage, manual extraction of placenta, pelvic hematoma requiring evacuation, cervical laceration repair, and thromboembolic events were noted in forceps compared to vacuum deliveries. When both instruments were used, rates of third/fourth degree lacerations and postpartum hemorrhage were increased. Operative delivery failure was highest in combined use compared to forceps or vacuum alone.

Conclusion: The incidence of operative vaginal delivery in California is declining, with decreasing use of forceps most notable. Several maternal morbidities are increased in forceps and combined deliveries compared to vacuum deliveries. There is a significantly higher risk of failure when two operative delivery methods are employed. These findings may be contributing to the declining willingness of providers to perform operative vaginal delivery.     

Vacuum assisted delivery in Ecuador for prolonged second stage of labor: Maternal–neonatal outcome

Background. In South America, and particularly Ecuador, cesarean section rates have risen markedly over the past five years. The associated increases in maternal morbidity and healthcare costs indicate the need for alternative strategies. Operative vaginal delivery is minimally utilized in Ecuador, as neither vacuum nor forceps have been available.

Objective. As vacuum delivery was recently introduced to our clinical service, we sought to examine our initial experiences (i.e., maternal and neonatal outcome) with operative vaginal delivery for prolonged second stage of labor.

Methods. Following an initial educational program at the Enrique C. Sotomayor Obstetrics and Gynecology Hospital, Guayaquil, Ecuador, vacuum extraction cups (Mityvac®, Cooper Surgical) were offered to laboring women with term singleton gestations and cephalic presentations no higher than +3 station. Maternal and neonatal data were analyzed.

Results. During the study period, 100 vacuum applications were performed on laboring women complicated with prolonged second stage of labor. Mean maternal age was 23.8 ± 6.4 years (range14–41 years) with 57% of patients nulliparous. Left anterior and right posterior fetal positions were the most frequent (85% and 11%, respectively). Maternal complications included need for blood transfusion (1%), shoulder dystocia (1%) and perineal tears (first degree 6%, second degree 5%). Vaginal delivery was successful in 97% of cases. Among neonates, the average weight was 3149 ± 410 g, with 10% neonates small for gestational age and 5% large for gestational age. Only 1% of infants presented an Apgar score <7 at 5 min. There were no scalp lacerations, cephalohematomas, or subgaleal bleeds.

Conclusions. In this initial observational study, vacuum extraction for prolonged second stage was safe and effective. We propose that the introduction of operative vaginal delivery to developing countries will mitigate rising cesarean section rates.     

Urinary incontinence in the 12-month postpartum period

OBJECTIVE: To describe the prevalence and severity of urinary incontinence in the 12-month postpartum period and to relate this incontinence to several potential risk factors including body mass index, smoking, oral contraceptives, breast-feeding, and pelvic floor muscle exercise. METHODS: Participants were 523 women, aged 14 to 42 years, who had obstetrical deliveries. The women were interviewed in their rooms on postpartum day 2 or 3 and by telephone 6 weeks, 3 months, 6 months, and 12 months postpartum. Chart abstraction was conducted to obtain obstetrical data from the index delivery. RESULTS: At 6 weeks postpartum, 11.36% of women reported some degree of urinary incontinence since the index delivery. Although the rate of incontinence did not change significantly over the postpartum year, frequency of accidents decreased over time. In the generalized estimating equation, postpartum incontinence was significantly associated with seven variables: baseline report of smoking (odds ratio [OR] 2.934; P =.002), incontinence during pregnancy (OR 2.002; P =.007), length of breast-feeding (OR 1.169; P =.023), vaginal delivery (OR 2.360; P =.002), use of forceps (OR 1.870; P =.024), and two time-varying covariates: frequency of urination (OR 1.123; P = <.001) and body mass index (OR 1.055; P =.005). Factors not associated with postpartum incontinence included age, race, education, episiotomy, number of vaginal deliveries, attendance at childbirth preparation classes, and performing pelvic floor muscle exercises during the postpartum period. CONCLUSION: Postpartum incontinence is associated with several risk factors, some of which are potentially modifiable and others that can help target at-risk women for early intervention.     

Factors predicting severe perineal trauma during childbirth: role of forceps delivery routinely combined with mediolateral episiotomy

OBJECTIVE: Anal sphincter injury and its sequelae are a recognized complication of vaginal childbirth. The aim of the present study was to identify risk factors for third- and fourth-degree perineal tears in patients undergoing either spontaneous or vaginal-assisted delivery by forceps routinely combined with mediolateral episiotomy. STUDY DESIGN: We retrospectively reviewed 5377 vaginal deliveries based on the analysis of the obstetric database and patient records of our department during a 5-year period from 1999 to 2003. Cases and control subjects were chosen randomly and patients' records were reviewed for the following variables: maternal age, parity, gestational age, tobacco use, gestational diabetes or pregnancy-induced hypertension, use of peridural anesthesia, duration of first and second stages of labor, use of mediolateral episiotomy, forceps combined with mediolateral episiotomy, induction of labor, infant head diameter, shoulder circumference, and birth weight. RESULTS: Of 5044 spontaneous vaginal deliveries 32 (0.6%) and of 333 assisted vaginal deliveries 14 (4.2%) patients sustained a perineal defect involving the external sphincter. An univariate analysis of these 46 cases and 155 randomly selected control subjects showed that low parity (P = .003; Mann-Whitney U test), prolonged first and second stages of labor (P = .001, P = .001), high birth weight (P = .031), episiotomy (P = .004; Fisher exact test), and forceps delivery (P = .002) increased the risk for sphincter damage. In multivariate regression models, only high birth weight (P = .004; odds ratio [OR] 1.68, 1.18-2.41, 95% confidence interval [CI]), and forceps delivery combined with mediolateral episiotomies (P < .001; OR 5.62, 2.16-14.62, 95% CI) proved to be independent risk factors. There was a statistical significant interaction of birth weight and head circumference (P = .012; OR 0.99, 0.98-0.99, 95% CI). Although the use of episiotomy conferred an increased risk toward a higher likelihood of severe perineal trauma, it did not reach statistical significance (P = .06; OR 2.15, 0.97-4.76, 95% CI). CONCLUSIONS: In consistence with previous reports, women who are vaginally delivered of a large infant are at a high risk for sphincter damage. Although the rate of these complications was surprisingly low in vaginally assisted childbirth, the use of forceps, even if routinely combined with mediolateral episiotomy, should be minimized whenever possible.     

Vacuum-Assisted Vaginal Delivery

Approximately 5% (1 in 20) of all deliveries in the United States are operative vaginal deliveries. The past 20 years have seen a progressive shift away from the use of forceps in favor of the vacuum extractor as the instrument of choice. This article reviews in detail the indications, contraindications, patient selection criteria, choice of instrument, and technique for vacuum-assisted vaginal delivery. The use of vacuum extraction at the time of cesarean delivery will also be discussed. With vacuum extraction becoming increasingly popular, it is important that obstetric care providers are aware of the maternal and neonatal risks associated with such deliveries and of the options available to effect a safe and expedient delivery.Key words: Operative vaginal delivery, Vacuum-assisted vaginal delivery, VacuumOperative vaginal delivery refers to the application of either forceps or a vacuum device to assist the mother in effecting vaginal delivery of a fetus. The incidence of operative vaginal delivery in the United States is currently estimated at around 5%, or approximately 1 in 20 deliveries,^1–4 although there are large geographic differences in the rates of operative vaginal delivery across the country.² The lowest rates of instrumental vaginal delivery (< 5%) are seen in the Northeast and the highest rates (20%–25%) are in the South.² Although the overall rate of operative vaginal delivery has been declining, the proportion of vacuum-assisted deliveries has been increasing and now accounts for almost 4 times the rate of forceps-assisted vaginal births.²     

Trends in major modifiable risk factors for severe perineal trauma, 1996–2006

OBJECTIVE: To examine what effect the major modifiable risk factors for severe perineal trauma have had on the rates of this trauma over time. METHODS: A retrospective observational cohort study of singleton vaginal deliveries taken from a perinatal database for the period 1996 through 2006. RESULTS: A total of 46,239 singleton vertex vaginal deliveries met the inclusion criteria. Major risk factors for severe perineal trauma were increased maternal age (odds ratio [OR] 1.28, 95% confidence interval [CI] 1.1-1.5), non-African American ethnicity (OR 1.5, 95% CI 1.3-1.7), nulliparity (OR 4.8, 95% CI 4.11-5.6), fetal birth weight (OR 2.2, 95% CI 1.9-2.4), forceps (OR 8.3, 95% CI 5.4-10.8), vacuum (OR 2.9, 95% CI 1.9-4.4), and midline episiotomy (OR 5.7, 95% CI 5.0-6.4). Evaluation of the changes in rates of these factors over the study period revealed that the decline in the rates of episiotomy and the use of forceps accounted for a reduction in severe lacerations of more than 50%. CONCLUSION: Reduction of severe perineal trauma by restricted use of the 2 modifiable clinical variables, episiotomy and forceps, is evident over time.