Williams ch.26Williams ch.26
Prior Cesarean Prior Cesarean DeliveryDelivery
부산백병원 산부인과부산백병원 산부인과R3 R3 박영미박영미
For many decades, a scarred uterus was believed to contFor many decades, a scarred uterus was believed to contraindicate labor out of fear of uterine ruptureraindicate labor out of fear of uterine rupture
Cragin (1916)Cragin (1916) Once a cesarean, always a cesareanOnce a cesarean, always a cesarean When this statement was made, the classical vertical uterine inciWhen this statement was made, the classical vertical uterine inci
sion was used almost universallysion was used almost universally
The ACOG (1998)The ACOG (1998) In the absence of a contraindication, a woman with one previous In the absence of a contraindication, a woman with one previous
low-transverse cesarean delivery be counseled to attempt labor ilow-transverse cesarean delivery be counseled to attempt labor in a subsequent pregnancy n a subsequent pregnancy
VBACVBAC Vaginal birth after cesareanVaginal birth after cesarean Pronounced : Vee backPronounced : Vee back
Trial of labor versus repeat cesarean Trial of labor versus repeat cesarean deliverydelivery
Candidates for a trial of laborCandidates for a trial of labor
Labor and delivery considerationsLabor and delivery considerations
Uterine ruptureUterine rupture
Trial of labor versus repeat Trial of labor versus repeat cesarean deliverycesarean delivery
Risks and benefitsRisks and benefits Beginning in 1989, VBAC increased,Beginning in 1989, VBAC increased, : A number of reports that suggested that : A number of reports that suggested that VBAC might be riskier than anticipatedVBAC might be riskier than anticipated
Scott (1991) : 12 uterine ruptureScott (1991) : 12 uterine rupture Two women : hysterectomyTwo women : hysterectomy Three : perinatal deathThree : perinatal death Two infants : long-term neurological impairmentTwo infants : long-term neurological impairment
Porter and colleages (1998) : 26 uterine rupturePorter and colleages (1998) : 26 uterine rupture 23% of the infants were dead or damaged (intrapartum asphyxia)23% of the infants were dead or damaged (intrapartum asphyxia)
Fewer women with a prior cesarean incision attempting vFewer women with a prior cesarean incision attempting vaginal deliveryaginal delivery
-> increased cesarean delivery rate -> increased cesarean delivery rate
Magnitude of riskMagnitude of risk Although uterine rupture and its complications Although uterine rupture and its complications
clearly are increased with a trial of labor, clearly are increased with a trial of labor, -> The absolute risk of complications is quite low-> The absolute risk of complications is quite low
These factors should weigh only minimally in the These factors should weigh only minimally in the decision to attempt VBACdecision to attempt VBAC
The absolute risk of uterine rupture resulting in The absolute risk of uterine rupture resulting in death or injury to the fetus : about 1 per 1000death or injury to the fetus : about 1 per 1000
The major controversy surrounding the The major controversy surrounding the management thus stems from the questionmanagement thus stems from the question
: Is a 1 per 1000 risk of having an otherwise : Is a 1 per 1000 risk of having an otherwise healthy healthy
fetus die or be damaged as a result of a trial of fetus die or be damaged as a result of a trial of labor acceptable ? labor acceptable ?
Maternal morbidityMaternal morbidity Maternal mortality : not appear to differ significantly comMaternal mortality : not appear to differ significantly com
pared with an elective repeat cesareanpared with an elective repeat cesarean
Maternal morbidity : conflicting resultMaternal morbidity : conflicting result In 2000, Mozurkewich and Hutton In 2000, Mozurkewich and Hutton : about half required a blood transfusion or hysterectomy : about half required a blood transfusion or hysterectomy compared with an elective repeat cesareancompared with an elective repeat cesarean In 2004, LandonIn 2004, Landon : the risks of transfusion and infection were significantly : the risks of transfusion and infection were significantly greater for a trial of laborgreater for a trial of labor In 1996, McMahon In 1996, McMahon : the major complication (hysterectomy, uterine rupture, : the major complication (hysterectomy, uterine rupture, operative injury) were twice as common in a trial of laboroperative injury) were twice as common in a trial of labor : fivefold greater at a vaginal delivery failed: fivefold greater at a vaginal delivery failed
CostsCosts
Grobman (2000), cohort of 100,000Grobman (2000), cohort of 100,000 The safety of VBAC as well as cost effectivenessThe safety of VBAC as well as cost effectiveness Routine repeat cesarean for a second birth was calculated to resRoutine repeat cesarean for a second birth was calculated to res
ult in an increased cost of $179millionult in an increased cost of $179million
DiMaio (2002)DiMaio (2002) Nearly $1100 higher for each elective repeat cesarean Nearly $1100 higher for each elective repeat cesarean
Clark (2000)Clark (2000) The cost of long-term care for neurologically injured infants is takThe cost of long-term care for neurologically injured infants is tak
en into account, trial of labor is unlikely to be associated with a sen into account, trial of labor is unlikely to be associated with a significant cost saving for the health care system ignificant cost saving for the health care system
Elective repeat cesarean Elective repeat cesarean deliverydelivery
PreferencePreference In spite of increased risks (anesthesia, hemorrhage, damage to tIn spite of increased risks (anesthesia, hemorrhage, damage to t
he bladder and other organs, pelvic infection, scarring), an electivhe bladder and other organs, pelvic infection, scarring), an elective repeat cesarean is considered to be preferable to attempting a e repeat cesarean is considered to be preferable to attempting a trial of labortrial of labor
Frequent reasonsFrequent reasons ① ① the convenience of a scheduled deliverythe convenience of a scheduled delivery ② ② the fear of a prolonged and potentially dangerous laborthe fear of a prolonged and potentially dangerous labor
Abitbol (1993)Abitbol (1993) 312 women studied, 125(40%) opted for a repeat cesarean312 women studied, 125(40%) opted for a repeat cesarean No complications in the elective cesarean groupNo complications in the elective cesarean group Two unanticipated fetal deaths in the VBAC groupTwo unanticipated fetal deaths in the VBAC group ① ① Scheduled cesarean : 93% were satisfied with their choiceScheduled cesarean : 93% were satisfied with their choice ② ② Elected a trial of labor : only 53% Elected a trial of labor : only 53% ③ ③ Uncomplicated trial of labor : 80% Uncomplicated trial of labor : 80%
Elective repeat cesarean Elective repeat cesarean deliverydelivery
Fetal maturityFetal maturity If elective repeat cesarean delivery is planned, it is If elective repeat cesarean delivery is planned, it is
essential that the fetus be matureessential that the fetus be mature
Candidates for a trial of Candidates for a trial of laborlabor
Type of prior uterine incisionType of prior uterine incision
Type of prior uterine incisionType of prior uterine incision The lowest risk of scar separationThe lowest risk of scar separation : the lower uterine segment transverse scar: the lower uterine segment transverse scar
The highest rates of rupture The highest rates of rupture : the classical incision (extending into the fundus) : the classical incision (extending into the fundus)
In about one third classical incision, the scar will rupture before tIn about one third classical incision, the scar will rupture before the on set of laborhe on set of labor
Not infrequently, rupture may take place several weeks before terNot infrequently, rupture may take place several weeks before term m
With uterine malformations, the risks for uterine rupture : With uterine malformations, the risks for uterine rupture : as high as with a classical incisionas high as with a classical incision In 1999, Ravasia In 1999, Ravasia : 8% rupture with unicornuate, bicornuate, didelphic, septate uteru: 8% rupture with unicornuate, bicornuate, didelphic, septate uteru
s s
Type of prior uterine incisionType of prior uterine incision
A prior vertical incision that did not extend into the funduA prior vertical incision that did not extend into the fundus : the risk of uterine rupture is controversials : the risk of uterine rupture is controversial Martin and Shipp (1997)Martin and Shipp (1997) : low-vertical uterine incision did not have an increased risk for rup: low-vertical uterine incision did not have an increased risk for rup
tureture The ACOG (2004)The ACOG (2004) : low-vertical incision without fundal extension may be candidates f: low-vertical incision without fundal extension may be candidates f
or VBAC or VBAC
Previously sustained a uterine rupture are at increased riPreviously sustained a uterine rupture are at increased risk for recurrencesk for recurrence A rupture confined to the lower segment : 6% recurrence risk A rupture confined to the lower segment : 6% recurrence risk Prior rupture included the upper uterus : 32% recurrence riskPrior rupture included the upper uterus : 32% recurrence risk
Closure of prior incisionClosure of prior incision
Whether the risk of subsequent uterine rupture is relateWhether the risk of subsequent uterine rupture is related to the number of layers is controversiald to the number of layers is controversial
Chapman (1997), Tucker (1993)Chapman (1997), Tucker (1993) : no relationship between a one-and two-layer closure and risk of : no relationship between a one-and two-layer closure and risk of
subsequent uterine rupturesubsequent uterine rupture Durnwald and Mercer (2003)Durnwald and Mercer (2003) : single layer closure -> no increased risk of rupture, uterine dehis: single layer closure -> no increased risk of rupture, uterine dehis
cencecence Bujold (2002)Bujold (2002) : single layer closure -> a fourfold increased risk of rupture compa: single layer closure -> a fourfold increased risk of rupture compa
red with a double layer closurered with a double layer closure Videaff and Lucas (2003)Videaff and Lucas (2003) : double layer closure -> wound healing have not demonstrated an: double layer closure -> wound healing have not demonstrated an
y advantagesy advantages
Closure of prior incisionClosure of prior incision
Healing of the cesarean incisionHealing of the cesarean incision
Willians (1921)Willians (1921) : By regeneration of the muscular fibers and : By regeneration of the muscular fibers and not by development of scar tissuenot by development of scar tissue : Inspection of the unopened uterus at repeat c/sec: Inspection of the unopened uterus at repeat c/sec -> no trace of the former incision-> no trace of the former incision -> almost invisible linear scar-> almost invisible linear scar
Schwarz (1938)Schwarz (1938) : By fibroblast proliferation: By fibroblast proliferation : the proliferation of connective tissue is minimal, : the proliferation of connective tissue is minimal, -> the normal relation of smooth muscle to -> the normal relation of smooth muscle to connective tissue gradually is reestablishedconnective tissue gradually is reestablished
Interdelivery intervalInterdelivery interval
If the hysterotomy scar did not have sufficient time to heIf the hysterotomy scar did not have sufficient time to healal
-> The risk of uterine rupture would be increased -> The risk of uterine rupture would be increased
Completer uterine involution and restoration of anatomy Completer uterine involution and restoration of anatomy (by studies using MRI)(by studies using MRI)
-> At least 6 months-> At least 6 months
Shipp (2001)Shipp (2001) : Interdelivery intervals of 18months or less: Interdelivery intervals of 18months or less -> threefold increased risk of symptomatic uterine -> threefold increased risk of symptomatic uterine rupturerupture
Number of prior cesarean Number of prior cesarean incisionincision
The risk of uterine rupture increases with the number of pThe risk of uterine rupture increases with the number of previous cesarean deliveriesrevious cesarean deliveries Landon (2004)Landon (2004) : twice as high in women with multiple prior cesareans compared : twice as high in women with multiple prior cesareans compared
with only one (1.4% versus 0.7%)with only one (1.4% versus 0.7%) Caughey (1999)Caughey (1999) : five fold in two previous cesareans compared with only one (3.7% : five fold in two previous cesareans compared with only one (3.7%
versus 0.8%)versus 0.8%)
Any previous vaginal delivery (before or after c/sec)Any previous vaginal delivery (before or after c/sec) -> significantly improves the prognosis for a -> significantly improves the prognosis for a subsequent successful VBACsubsequent successful VBAC -> lowers the risk of subsequent uterine rupture-> lowers the risk of subsequent uterine rupture
ACOG (2004) ACOG (2004) : two prior low-transverse c/sec with a prior vaginal delivery : two prior low-transverse c/sec with a prior vaginal delivery should be considered for VBACshould be considered for VBAC
Indication for prior cesarean Indication for prior cesarean deliverydelivery
The success rate for a trial of labor depends to tThe success rate for a trial of labor depends to the indication for the previous c/seche indication for the previous c/sec
Wing and Paul (1999), O’Herlihy(1998)Wing and Paul (1999), O’Herlihy(1998) : breech presentation -> 91% successful VBAC: breech presentation -> 91% successful VBAC : fetal distress -> 84% successful VBAC: fetal distress -> 84% successful VBAC : dystocia -> 68% successful VBAC: dystocia -> 68% successful VBAC
Hoskins and Gomez (1997) Hoskins and Gomez (1997) (relation to cervical dilation) (relation to cervical dilation) : cervix 5cm or less -> 67% successful VBAC: cervix 5cm or less -> 67% successful VBAC : cervix 6 to 9cm -> 73% successful VBAC: cervix 6 to 9cm -> 73% successful VBAC
Fetal macrosomiaFetal macrosomia
Increasing fetal size would increase the risk of utIncreasing fetal size would increase the risk of uterine rupture with VBACerine rupture with VBAC
Zelop (2001)Zelop (2001) : weighed less than 4000g -> 1.0% rupture : weighed less than 4000g -> 1.0% rupture : Infants weighed at least 4000g -> 1.6% rupture : Infants weighed at least 4000g -> 1.6% rupture : birth weight exceeded 4250g -> 2.4% ruptuer: birth weight exceeded 4250g -> 2.4% ruptuer
Elkousy (2003)Elkousy (2003) : no previous vaginal deliveries, the birthweight at : no previous vaginal deliveries, the birthweight at least 4000g least 4000g -> the doubled risk of uterine rupture-> the doubled risk of uterine rupture
Maternal obesityMaternal obesity
Carroll (2003)Carroll (2003)
: As maternal weight increased, the rate of : As maternal weight increased, the rate of
VBAC success decreasedVBAC success decreased
Edward (2003)Edward (2003)
: Puerperal infection was higher in obese : Puerperal infection was higher in obese
women attempting a trial of laborwomen attempting a trial of labor
Labor and Delivery Labor and Delivery ConsiderationsConsiderations
Guidelines for women with a prior cesarean who have chosen a trial Guidelines for women with a prior cesarean who have chosen a trial of labor (the ACOG,2002) of labor (the ACOG,2002)
⑴ ⑴ Prompt evaluation of the laboring patient must be Prompt evaluation of the laboring patient must be performedperformed
⑵ ⑵ Continuous electronic monitoring of fetal heart rate and Continuous electronic monitoring of fetal heart rate and uterine contractions should be considereduterine contractions should be considered ⑶ ⑶ Personnel familiar with the potential complications of a trial of Personnel familiar with the potential complications of a trial of labor should be vigilant for nonreassuring fetal heart rate labor should be vigilant for nonreassuring fetal heart rate patterns and inadequate progress of laborpatterns and inadequate progress of labor
⑷ ⑷ Attempts should be limited to institutions with physicians Attempts should be limited to institutions with physicians immediately available to provide emergency careimmediately available to provide emergency care
The ACOG (2002) recommend that the following issues bThe ACOG (2002) recommend that the following issues be addressed before the ultimate decision to attempt a vae addressed before the ultimate decision to attempt a vaginal deliveryginal delivery
⑴ ⑴ Advantages of a successful vaginal delivery, for Advantages of a successful vaginal delivery, for example, shorter postpartum hospital stay; less example, shorter postpartum hospital stay; less painful, more rapid recovery; and otherspainful, more rapid recovery; and others
⑵ ⑵ Contraindications to a trial of labor, for example, Contraindications to a trial of labor, for example, prior classical cesarean, placenta previa, and othersprior classical cesarean, placenta previa, and others
⑶ ⑶ Risk of uterine rupture (approximately 1%)Risk of uterine rupture (approximately 1%)
⑷ ⑷ Increased risk of uterine rupture with more than one Increased risk of uterine rupture with more than one prior cesarean delivery, attempts at cervical ripening prior cesarean delivery, attempts at cervical ripening or labor induction, macrosomia, and oxytocin or labor induction, macrosomia, and oxytocin augmentationaugmentation
⑸ ⑸ In the event of rupture, there is a 10 to 25 percent In the event of rupture, there is a 10 to 25 percent risk of significant adverse fetal sequelaerisk of significant adverse fetal sequelae
⑹ ⑹ Although catastrophic uterine rupture leading to Although catastrophic uterine rupture leading to perinatal death or permanent neonatal injury is rare, perinatal death or permanent neonatal injury is rare, occurring less often than 1 per 1000 VBAC attempts, occurring less often than 1 per 1000 VBAC attempts, it dose occur despite the best available resourcesit dose occur despite the best available resources
Cervical ripening and labor Cervical ripening and labor stimulationstimulation
Any attempt to induce cervical ripening orAny attempt to induce cervical ripening or
to induce or augment labor to induce or augment labor
=> Increases the risk of uterine rupture in => Increases the risk of uterine rupture in
women undergoing a trial of laborwomen undergoing a trial of labor
Cervical ripening and labor Cervical ripening and labor stimulationstimulation
OxytocinOxytocin
Use of oxytocin to induce or augment labor has been implicated iUse of oxytocin to induce or augment labor has been implicated in uterine ruptures in women attempting VBACn uterine ruptures in women attempting VBAC
Oxytocin dose and duration correlated directly with uterine ruptureOxytocin dose and duration correlated directly with uterine rupture
The ACOG (2002)The ACOG (2002) : Oxytocin may be used for both labor induction : Oxytocin may be used for both labor induction and augmentation with close patient monitoring in and augmentation with close patient monitoring in women with a prior cesarean delivery undergoing women with a prior cesarean delivery undergoing a trial of labora trial of labor
Cervical ripening and labor Cervical ripening and labor stimulationstimulation
Experiences at Parkland HospitalExperiences at Parkland Hospital : Between 1986 and 1990: Between 1986 and 1990
1482 delivered vaginally, 1482 delivered vaginally, uterine rupture : 1.5 per 1000uterine rupture : 1.5 per 1000 Another 307 women received oxytocin, Another 307 women received oxytocin, uterine rupture : 10 per 1000 uterine rupture : 10 per 1000
=> Our experience with uterine ruptures led us to => Our experience with uterine ruptures led us to the decision to discontinue the use of oxytocin the decision to discontinue the use of oxytocin in women with prior cesarean deliveriesin women with prior cesarean deliveries
Cervical ripening and labor Cervical ripening and labor stimulationstimulation
ProstaglandinsProstaglandins
Prostaglandins use in women attempting VBAC Prostaglandins use in women attempting VBAC -> increases the risk of uterine rupture-> increases the risk of uterine rupture
Ravasia (2000)Ravasia (2000) : the rate of uterine rupture was significantly : the rate of uterine rupture was significantly greater in the women treated with prostaglandingreater in the women treated with prostaglandin E2 gel than in those having spontaneous laborE2 gel than in those having spontaneous labor (2.9% versus 0.5%)(2.9% versus 0.5%)
Lydon-Rochelle (2001)Lydon-Rochelle (2001) : The risk of uterine rupture was nearly 16-fold greater for women u: The risk of uterine rupture was nearly 16-fold greater for women u
ndergoing induction of labor with prostaglandins compared with tndergoing induction of labor with prostaglandins compared with that of a repeated cesarean delivery hat of a repeated cesarean delivery
Epidural analgesiaEpidural analgesia
The use of epidural analgesia for labor in women with a pThe use of epidural analgesia for labor in women with a prior cesarean delivery was debated in the past rior cesarean delivery was debated in the past
=> masking the pain of uterine rupture=> masking the pain of uterine rupture
HoweverHowever Less than 10% of women with scar separation experience pain aLess than 10% of women with scar separation experience pain a
nd bleedingnd bleeding Fetal heart rate decelerations are the most likely sign of ruptureFetal heart rate decelerations are the most likely sign of rupture
The ACOG (20020The ACOG (20020 Epidural analgesia may safely be used during a trial of laborEpidural analgesia may safely be used during a trial of labor The anesthesia service be notified whenever a woman with a prioThe anesthesia service be notified whenever a woman with a prio
r cesarean is admitted in active laobrr cesarean is admitted in active laobr
Uterine scar explorationUterine scar exploration
Surgical correction of a scar dehiscence is necesSurgical correction of a scar dehiscence is necessary only if significant bleeding is encounteredsary only if significant bleeding is encountered
Asymptomatic separations Asymptomatic separations => Do not generally require exploratory=> Do not generally require exploratory laparotomy and repairlaparotomy and repair
Uterine ruptureUterine rupture
ClassificationClassification
Complete uterine ruptureComplete uterine rupture All layer of the uterine wall separatedAll layer of the uterine wall separated
Incomplete uterine rupture (= uterine dehiscence)Incomplete uterine rupture (= uterine dehiscence) Uterine muscle separated but visceral peritoneum is intactUterine muscle separated but visceral peritoneum is intact
Morbidity and mortality are appreciably greater Morbidity and mortality are appreciably greater when rupture is completewhen rupture is complete
The greatest risk factor for either complete or The greatest risk factor for either complete or incomplete uterine ruptureincomplete uterine rupture
=> Prior cesarean delivery=> Prior cesarean delivery
Diagnosis Diagnosis The symptoms and physical findings may appear bizarre The symptoms and physical findings may appear bizarre
unless the possibility of uterine rupture is dept in mindunless the possibility of uterine rupture is dept in mind Hemoperitoneum Hemoperitoneum : Irritation of the diaphragm with pain referred to the chest : Irritation of the diaphragm with pain referred to the chest -> pulmonary or amnionic fluid embolism -> pulmonary or amnionic fluid embolism
Intrauterine pressure cathetersIntrauterine pressure catheters: Few women experience cessation of contractions following: Few women experience cessation of contractions following uterine ruptureuterine rupture – –> not shown to assist reliably in the diagnosis> not shown to assist reliably in the diagnosis
The most common electronic fetal monitoring findingThe most common electronic fetal monitoring finding: Sudden, severe heart rate decelerations : Sudden, severe heart rate decelerations (late decelerations, bradycardia, undetectable fetal heart action)(late decelerations, bradycardia, undetectable fetal heart action)
DiagnosisDiagnosis
Remarkably little appreciable pain or tendernessRemarkably little appreciable pain or tenderness Most women in labor are treated for discomfort with narcotics, luMost women in labor are treated for discomfort with narcotics, lu
mbar epidural analgesiambar epidural analgesia
The evident conditionThe evident condition Signs of fetal distressSigns of fetal distress Maternal hypovolemia from concealed hemorrhageMaternal hypovolemia from concealed hemorrhage
Pelvic examinationPelvic examination The fetal presenting part has entered the pelvis The fetal presenting part has entered the pelvis -> Loss of station-> Loss of station If the fetus is partly or totally extruded from the site of rupture If the fetus is partly or totally extruded from the site of rupture -> the presentign part moved away from the pelvic inlet -> the presentign part moved away from the pelvic inlet -> a firm contracted uterus may be felt alongside the fetus-> a firm contracted uterus may be felt alongside the fetus
PrognosisPrognosis Rupture and expulsion of the fetus into the peritoneal cavRupture and expulsion of the fetus into the peritoneal cav
ity ity -> the chances for intact fetal survival are dismal-> the chances for intact fetal survival are dismal -> mortality rates : 50~75%-> mortality rates : 50~75%
Fetal condition depends on how much placenta is intactFetal condition depends on how much placenta is intact -> likely decreases over minutes-> likely decreases over minutes
If the fetus is alive at the time of rupture If the fetus is alive at the time of rupture -> immediate delivery, most often by laparotomy-> immediate delivery, most often by laparotomy
The maternal prognosis The maternal prognosis much better and seldom fatal much better and seldom fatal If untreated -> most women would die from hemorrhage or If untreated -> most women would die from hemorrhage or later from infectionlater from infection
Hysterectomy versus repairHysterectomy versus repair
Scar separation without bleeding Scar separation without bleeding : Exploratory laparotomy is not indicated: Exploratory laparotomy is not indicated
Frank ruptureFrank rupture : Hysterectomy may be required: Hysterectomy may be required