Vaginal Birth After Previous CesareanDelivery
Trial of  labor  after  previous  cesarean  delivery  (TOLAC) provides  women  who  desire  a  vaginal  delivery  with  thepossibility of achieving that goal––a vaginal birth after cesarean delivery (VBAC)?. In addition to fulfilling a patient’spreference for vaginal delivery, at an individual level VBAC is associated with decreased maternal morbidity and adecreased risk of complications in future pregnancies. At a population level, VBAC also is associated with a decreasein  the  overall  cesarean  delivery  rate  (1,  2).  Although  TOLAC  is  appropriate  for  many  women  with  a  history  of  acesarean  delivery,  several  factors  increase  the  likelihood  of  a  failed  trial  of  labor,  which  compared  with  VBAC,  isassociated with increased maternal and perinatal morbidity (3–5). Assessment of individual risks and the likelihood ofVBAC is, therefore, important in determining who are appropriate candidates for TOLAC. The purpose of this docu-ment is to review the risks and benefits of TOLAC in various clinical situations and provide practical guidelines formanaging and counseling patients who will give birth after a previous cesarean delivery.
Background
Between  1970  and  2007,  the  cesarean  delivery  rate  inthe  United  States  increased  dramatically  from  5%  tomore  than  31%  (6,  7).  This  increase  was  a  result  ofseveral  changes  in  the  practice  environment,  includingthe  introduction  of  electronic  fetal  monitoring  and  thedecrease in use of vaginal breech deliveries and forcepsdeliveries (8–10). The increase in cesarean delivery rateswas  partly  perpetuated  by  the  dictum  “once  a  cesareanalways  a  cesarean”  (11).  In  the  1970s,  however,  somebegan to reconsider this paradigm, and accumulated datahave since supported TOLAC as a reasonable approachin selected pregnancies (4, 5, 12–14).
This  change  in  approach  and  recommendationsfavoring TOLAC was reflected in increased VBAC rates(VBAC per 100 women with a prior cesarean delivery)from  just  more  than  5%  in  1985  to  28.3%  by  1996.The overall cesarean delivery rate decreased to approxi-mately 20% by 1996 (15). Yet, as the number of womenpursuing  TOLAC  increased,  so  did  the  number  of  re-ports  of  uterine  rupture  and  other  complications  duringTOLAC (16–18). In part, these reports, and the profes-sional liability pressures they engendered, have resultedin a reversal of VBAC and cesarean delivery trends. By2006,  the  VBAC  rate  had  decreased  to  8.5%  and  thetotal cesarean delivery rate had increased to 31.1% (15,19, 20). In some hospitals, TOLAC is no longer offered.
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