Factors Affecting The Success Of Trial Of Labour After Previous One Cesarean Section:

Hassan Ahmed Radwan

As cesarean rates are markedly increased specially in the last 20 years allover the world due to the development of safer surgical techniques and ancillary services (e.g., blood typing and transfusion, antibiotic therapy), the national interest arose in reducing the rate of repeat cesarean, the leading indication for CD by allowing more and more trial for vaginal birth after cesarean.• The VBAC rate, defined as the proportion of women who delivered vaginally after prior CD. It is steadily increased from 1989 to 1996, but it has been decreasing each year thereafter.• Discussions about vaginal delivery after prior CD first appeared in the literature in 1916. Cragin, who is attributed with coining the phrase “once a cesarean, always a cesarean,” described cases of women surviving vaginal birth after cesarean (VBAC). The National Institute of Child Health and Human Development (NICHD) convened a Consensus Development Conference in 1980 to assess why cesarean rates were rising and to determine whether CD resulted in improved fetal outcomes. It was determined that TOL after prior low transverse cesarean posed low risk to fetus and mother, but more data with larger numbers were needed. After 1980, VBAC rates rose. A series of highly publicized articles suggested that VBAC was associated with higher risks of uterine rupture and maternal and perinatal morbidity. As Most recent reports support the safety of VBAC in women with one cesarean as well as its cost effectiveness for the patients, her family and for heath care system, this make VBAC rates in a steady increase specially in women who had cesarean section due to breech presentation, fetal distress, pregnancy induced hypertension, ante partum hemorrhage and multiple gestation, these indications are often non-recurring and many of those women when become pregnant again there is no contraindications for attempting vaginal delivery.• The determinants of success rate of TOL depends mainly on the location and healing of previous cesarean scar which is much better in lower uterine segment. This is determined by proper antenatal care (history taking, clinical examination of scar by inspection of shape and palpation for tenderness), by special investigations for integrity of the scar specially ultrasound then on adequacy of maternal pelvis and fetal head size. In addition to the other predictors of success of the TOL from previous trials such as prior vaginal birth especially if the vaginal birth occurred after the caesarean section, Non-recurrent indication for the previous caesarean (for example, breech presentation or placenta previa), maternal cervical dilatation at time of admission specially if greater than 4cm,fetal weight less than 4000gm,fetal gestational age less than 42weeks upon assessment of labour, Maternal age < 40 years, and High motivation for vaginal birth .The previous points must be well assessed to establish a plan about allowing TOL or repeating cesarean.• Female counseling is a very important factor by explaining benefits of VBAC (lower rate of maternal death compared to caesarean section (approximately 40 per 100,000 births with cesarean and 10 per 100,000 births with vaginal, less requirement for blood transfusion, fewer hysterectomies, less febrile morbidity and shorter hospital stays ) and risks of the trial (risk of uterine rupture with rates from 0.1% to 1.5% with a previous low-segment caesarean section as quoted in the literature.• Precautions should be taken before deciding TOL and during it includes (previous operative report should be obtained wherever possible, a consent form should be used for women planning VBAC., use of elective induction should be minimized wherever possible, discussion regarding choice of birth place, it is important to review thoroughly the increased morbidity and/or mortality that may be caused by the delay to surgical intervention in the event of uterine rupture at home or in a level I hospital so the place of birth should be ready for immediate interference as regard anesthesia and blood banking, monitoring for signs and symptoms of uterine rupture during labour by midwives, Fetal heart monitoring should be either a) intermittent auscultation every 15 minutes in active labour and every 5 minutes in second stage, any fetal heart rate abnormalities are heard or there are any other signs associated with rupture and It is recommended that a labour partogram be employed to accurately identify dystocia and facilitate appropriate consultation• As regard the outcome of our trial of labour together with the previous studies we observed that the success rate was high and the fetal and maternal outcome were good as there were no maternal or fetal mortality in both the successful and the failed groups.• And finally, we can conclude that VBAC is one of the best methods to decrease the high and rising rate of cesarean provided good selection of patients and following the guidelines for management of TOL. Physicians must be encouraged to do such trial after explaining the high success rate allover the world and starting early educational programs for pregnant women to be ready for the trial before onset of labour.