VAGINAL BIRTH AFTER CESAREAN SECTION : VAGINAL BIRTH AFTER CESAREAN SECTION Ajanta Samanta Slide 2: INTRODUCTION
CONDUCTION OF LABOR
SUMMARY Introduction : : Introduction : “once cesarean always cesarean” – Cragin,1916
Low transverse uterine incision –by Kerr,1920
1950 onwards,vaginal delivery tried in nonrecurring cause with prior low transverse incision
Incidence of uterine rupture -4% vs 0.5% with success rate 30-40% in Prior LSCS Slide 4: 1980-1988 Cs rate rises ,17% - 24%
In 1988 ACOG recommended –most women with one previous LTCS should be counseled to attempt labor in subsequent pregnancy.
1996 VBAC rate ↑dramatically, almost a third women with prior LTCS delivered vaginally.
But comparing various risks VBAC rates again decreased gradually & reduced to 10% in 2004 in US Fetal & Maternal risks with VBAC : Fetal & Maternal risks with VBAC : Landon et al. N Engl J Med 2004 Slide 9: Overall, woman attempting VBAC have 50% greater morbidity, though this depends on background risks of failure. [B]
Absolute risk of maternal morbidity-
highest with failed VBAC- 14.1%
Intermediate with PRCS -3.6%
Lowest with successful VBAC -2.4% [B] RCOG 2008 Maternal risks with VBAC Vs PRCD : Maternal risks with VBAC Vs PRCD Short term :VBAC
Vaginal & perineal laceration
Trauma to anal sphincter & mucosa
Serious intraoperative injury during EmLUCS
Short term :PRCD
Venous thromboembolism Long term maternal risks : Long term maternal risks VBAC:
Urinary incontinence in operative vaginal delivery
Rupture in this pregnancy ↑es rupture risk in future pregnancy
Anterior placenta previa wth morbid adherence
Morbidly adherent placenta-accreta, percreta
Increased adherence & operative injury in future sx- hysterectomy Fetal risks : Fetal risks Short term: VBAC
Uterine rupture with antepartum stillborn
HIE & intrapartum still born
Primary pulmonary hypertension Long term fetal risks : Long term fetal risks VBAC :
HIE leading to cerebral palsy
Early onset schizophrenia in later life from complicated cesarean delivery Candidates for Vaginal Birth after Cesarean Delivery (VBAC) : Candidates for Vaginal Birth after Cesarean Delivery (VBAC) Classic candidates
One previous prior low-transverse cesarean delivery done for nonrecurring indication
Clinically adequate pelvis , without any contraindication of vaginal delivery
Having singleton pregnancy in longitudinal lie & cephalic presentation
No other uterine scars or previous rupture
Physician immediately available throughout active labor capable of monitoring labor and performing an emergency cesarean delivery
Availability of anesthesia and personnel for emergency cesarean delivery ACOG, 2004 Special candidates : Special candidates RCOG 2008 Predictive Normogram : Predictive Normogram Predictive normogram : Predictive normogram Predictors of scar rupture Vs successful VBAC : Predictors of scar rupture Vs successful VBAC Type of prior uterine incision and Estimated Risks for Uterine Rupture : Type of prior uterine incision and Estimated Risks for Uterine Rupture ACOG, 2004 Closure of prior incision : Closure of prior incision Single layer closure of a low transverse incision associated with 4- 5 fold increased risk of scar ruptures after adjustment of other maternal & demographic factors
Uterine rupture more likely with previous single layer closure. [B] BUJOLD E, Am J Obstet Gynecol,2002 Timing of previous C.S : Timing of previous C.S Performed in latent lobour or without labour Vs in labour
Nulliparous labour needs stronger & longer contractions to dilate nulliparous cervix- more strain on old scar- more chance of scar rupture Interdelivery interval : Interdelivery interval MRI studies of myometrial healing suggests complete uterine involution & restoration of anatomy needs at least 6 months.
Interpregnancy interval <6 months -3 fold increased risk of uterine rupture, &
Interval 6-18months does not significantly alters rupture risk. SHIPP & ASSOCIATES, 2001 No. of prior C.S : No. of prior C.S Risk of uterine rupture increases with increase in the no. of prior cesarean section.
In one study 0.6% Vs 1.8% incidence of rupture with previous one Vs two L.T.C.S MILLER & ASSOCIATES ,1994 Thickness of lower uterine segment by USG : Thickness of lower uterine segment by USG Measurement of lower uterine segment thickness at 3rd trimester may have some predictive role for uterine rupture in VBAC.
If lower segment become very thin chances of scar rupture is very high.
But absolute criteria needs further evaluation. History of prior vaginal delivery : History of prior vaginal delivery Previous vaginal delivery either before or following cesarean birth significantly improves the prognosis of future trial for VBAC & lowers the risk of uterine rupture.
According to ACOG(2004) , VBAC can be considered even in a woman with prior two L.T.C.S only if she has a prior vaginal delivery. Indication of prior C.S : Indication of prior C.S Success rate of vaginal delivery is good when indication of previous C.S was breech presentation or fetal distress.
(91% & 84%-PAUL,1999)
Success rate low if baby WT in recent pregnancy >500gms than previous one.
Significant low success rate of VBAC where prior indication was dystocia. Fetal size : Fetal size Increasing fetal size increases risk of rupture in VBAC shows by various studies-
Zelop & associates(2001) shows – rupture rate in VBAC- 1% for FW<4000g, 1.6% for 4000-4250g, & 2.4% with FW>4250g
Planned preterm VBAC have similar success rate like planned term VBAC but with a lower risk of scar rupture. [C] Multifetal gestation : Multifetal gestation Twin pregnancy as such does not increase risk of rupture with VBAC, but
There may be need for intrauterine manipulation before delivery of 2nd twin , which must be considered according to the situation.
Caution must be advised when considering planned VBAC in twin pregnancy [B] Maternal obesity : Maternal obesity Maternal obesity adversely affects success of VBAC
Success rate highest with BMI <25 & success rate gradually decreases as BMI increases, & become minimum when >40 (85% Vs 61%, HIBBARD & colleagues, 2006) Slide 30: Gestational diabetes :
History of gestational diabetes associated with a high background rate of failure & low threshold for emergency C.S during VBAC.
Slow progress of labor :
Associated with increased failure rate in VBAC.
[B] Informed consent : Informed consent Decision of either VBAC or planed repeat cesarean section should be taken
By the informed woman,
In conjunction with her physician
After thoroughly analyzing that particular
situation. Slide 32: Recommended Counseling Points for Women with a Prior Cesarean Delivery( RCOG,2008) Recommended Counseling Points for Women with a Prior Cesarean Delivery( RCOG,2008) : Recommended Counseling Points for Women with a Prior Cesarean Delivery( RCOG,2008) Slide 34: RCOG 2008 Conduction of labor in VBAC : Conduction of labor in VBAC Advised to get admitted in hospital early in the labor
Once labor established , an I.V drip should be maintained.
Blood should be sent for CM & kept reserved for future transfusion. [GPP]
Facility should be available for continuous intrapartum monitoring, EmLUCS, advanced neonatal resuscitation. [B]
FHR should be monitored carefully, & continuous electronic fetal HR monitoring should be instituted. [B] Slide 36: Epidural analgesia can be used safely during labour(ACOG,2007) [C]
Spontaneous onset of labor is most desirable
If cervix is favorable , amniotomy may be done without any additional risks
Continuous monitoring of progress of labour & maternal vitals should be done. [GPP]
If progress satisfactory, successful outcome is expected
Routine use of I.U pressor catheter for early detection of rupture is not recommended. [C] Cervical ripening & labor stimulation : Cervical ripening & labor stimulation Two to three fold increased risk of uterine rupture & 1.5 fold increased risk of C.S in induced &/ augmented labor than spontaneous labor in VBAC. [B]
So oxytocin should be used with extreme caution & only when uterine activity is clearly inadequate & great care should be taken to avoid uterine hyperstimulation. [B] Slide 38: Prostaglandins for cervical ripening is associated with increased risk of scar rupture during VBAC
Rupture rate clearly higher than spontaneous labor in most of the studies.
Thus ACOG(2004), discourages the use of prostaglandin analogues for cervical ripening or labor induction during VBAC. [GPP] (2.9% Vs 0.9% in PGE2 gel Vs spontaneous, RAVASIA ET AL,2000) Contd.. : Contd.. 2nd stage of labor is the period of maximum strain to the lower uterine segment, so…
If 2nd stage is prolonged & head is low in the pelvis –this may be shortened with assisted vaginal delivery, by forceps or by vacuum Slide 40: 3rd stage is usually uneventful.
Routine exploration of uterine scar after delivery is no longer recommended, because cases needs surgical repair are almost invariably symptomatic. [B]
Woman must be observed intensely in early postpartum period for any signs of scar rupture Recent trends of VBAC : Recent trends of VBAC Summary : Summary “Best answer” for a given woman with a prior C.S is probably unknown.
The decision to attempt VBAC is complex, requires careful counseling & should take into consideration :
Maternal preferences & priorities
plans for future pregnancies
Presence of factors that influence likelihood of success Vs scar rupture
importance placed on rare but serious adverse outcomes Slide 43: The National Institute of health is planning to organize a “consensus development conference” in 2010 to minimize some confusion & to arrive at a decision & to elucidate current knowledge on VBAC . Slide 44: THANK YOU