True rupture of the caesarean section scar (a 15 year review, 1972-1987)

A trial of labor after cesarean section in patients with or without a prior vaginal delivery

OBJECTIVE

To determine the outcome of labor in women with a previous cesarean section, with or without prior vaginal delivery.

METHOD

Records were reviewed for 1065 women with a previous cesarean section at 'Virgen Macarena' Hospital who were attended for a subsequent labor.

RESULTS

Chi-squared tests demonstrated that women with previous vaginal delivery (n = 346) had a significantly higher rate of vaginal delivery after a trial of labor (95.24%) than those without previous vaginal delivery (n = 719) (82.95%). All the ruptures of uterine scar (n = 4) were found in women without previous vaginal delivery.

CONCLUSION

It appears that a cesarean section in a multiparous woman is not a determinant fact in her reproductive history and the risk of rupture of uterine scar did not appear to be present.

Obstetric decision-making and the late and moderately preterm infant

The decision of when to deliver a patient for medical or obstetric complication directly affects the neonatal outcome. When the fetus is in danger due to suspected utero-placental insufficiency, the decision to deliver is thought to benefit the neonate. However, the opposite may be true when a normally developing fetus needs to be delivered for a maternal indication such as a persistently bleeding placenta praevia. These decisions are made daily by obstetric providers. The following is a review of obstetric decision-making for moderate and late preterm pregnancies.

Risk factors for uterine rupture during a trial of labor after cesarean

The rate of vaginal birth among women with a previous cesarean increased from 18.9% in 1989 to 28.3% in 1996. By 1998, the rate had decreased to 26.3% and preliminary data from 1999 suggest that the rate for that year would be even lower (23.4%). It is not known whether that decrease represents a trend related to increasing concern by providers and women about the risk of uterine rupture. Whereas the overall risk of rupture is 1%, our review demonstrates that there is considerable variation of that risk. More than one previous scar, induction of labor, a short interdelivery interval, or a history of postpartum fever during a previous cesarean may increase the risk of a uterine rupture during a trial of labor. However, there does not appear to be an increase in risk associated with low-vertical scars, and a previous vaginal delivery may be somewhat protective. Further delineation of the factors that increase the risk of uterine rupture will permit better prediction of individualized risk and identification of women for whom attempting a vaginal delivery after cesarean represents a safe option.

Elective repeat cesarean delivery versus trial of labor: a meta-analysis of the literature from 1989 to 1999

OBJECTIVE

The aim of this study was to compare a trial of labor with elective repeat cesarean delivery among women with previous cesarean delivery.

STUDY DESIGN

We searched MEDLINE and EMBASE databases from 1989 through 1999 with the following terms: vaginal birth after cesarean delivery, trial of labor, trial of scar, and uterine rupture. We included all controlled trials from developed countries in which the control group had been eligible for a trial of labor. Outcomes of interest were uterine rupture, hysterectomy, maternal febrile morbidity, maternal mortality, 5-minute Apgar score <7, and fetal or neonatal mortality. We computed pooled odds ratios for each outcome.

RESULTS

The search strategy identified 52 controlled studies, 37 of which were excluded because many of the control subjects were not eligible for a trial of labor. Fifteen studies with a total of 47,682 women were included. Uterine rupture occurred more frequently among women undergoing a trial of labor than among those undergoing elective repeat cesarean delivery (odds ratio, 2.10; 95% confidence interval, 1.45-3.05). There was no difference in maternal mortality risk between the 2 groups (odds ratio, 1.52; 95% confidence interval, 0.36-6.38). Fetal or neonatal death (odds ratio, 1.71; 95% confidence interval, 1.28-2.28) and 5-minute Apgar scores <7 (odds ratio, 2.24; 95% confidence interval, 1.29-3.88) were more frequent in the trial of labor group than in the control group. Mothers undergoing a trial of labor were less likely to have febrile morbidity (odds ratio, 0.70; 95% confidence interval, 0.64-0.77) or to require transfusion (odds ratio, 0.57; 95% confidence interval, 0.42-0.76) or hysterectomy (odds ratio, 0.39; 95% confidence interval, 0.27-0.57).

CONCLUSION

A trial of labor may result in small increases in the uterine rupture rate and in fetal and neonatal mortality rates with respect to elective repeat cesarean delivery. Maternal morbidity, including febrile morbidity, and the need for transfusion or hysterectomy may be reduced with a trial of labor.

Routine revision of uterine scar after cesarean section: has it ever been necessary?

Although a trial of labor after cesarean section (VBAC) is successful and relatively safe, few studies have directly addressed the necessity of routine transcervical revision of uterine scar after prior cesarean section. We performed a longitudinal study of 3469 women who had VBAC. In all patients, uterine scar integrity was examined immediately after placental expulsion. The detection rate of uterine scar dehiscence or rupture was 0.23% (8/3469). Only one woman with complete uterine rupture needed immediate laparotomy for severe hemorrhage. Out of seven patients (0.2%), who had evidence of uterine dehiscence, three underwent explorative laparotomy. In conclusion, the potential benefit of routine examination of uterine scar after VBAC is doubtful. Transcervical revision should be performed only in symptomatic patients.

The relationship between gestational age and the incidence of classical caesarean section

Improved neonatal survival has led to a rise in the number of Caesarean sections being performed in the presence of extreme prematurity. Many of these operations require an incision in the upper uterine segment with consequent ramifications for the management of any subsequent pregnancy. In this analysis of obstetric patients in a tertiary referral institution over a 9-year period, there was an overall Caesarean section rate of 18%. A classical incision was performed in 1% of all caesarean sections, but at 24 weeks' gestation, 20% of Caesarean sections were 'classical'. This frequency decreased to less than 5% at 30 weeks and less than 1% from 34 weeks' gestation. Most women having a classical Caesarean section at term had either a transverse lie or a major degree of placenta praevia.

Maternal urological injuries associated with vaginal deliveries: change of pattern

Injury to the maternal lower urinary tract is related to the standard of obstetric care and to different techniques utilized in delivery. In comparison with operative delivery, maternal urinary tract injury in association with vaginal delivery had always been exceptionally rare. However, with the recent progress in obstetric care and the introduction of new concepts such as vaginal delivery after caesarian section (VDAC), the pattern of maternal urological injuries associated with vaginal deliveries might have changed. In a retrospective study it was found that significant injuries to the lower urinary tract occurred in seven females in the course of vaginal delivery in the period between 1992 and 1994 in two major hospitals in the Riyadh area. These included rupture of the posterior bladder wall, trigone and bladder neck. Distal ureteric and urethral injuries, as well as bladder contusion were also encountered. Two patients developed vesico-uterine and vesico-vaginal fistulas. History of previous caesarian section was present in 4 patients. All deliveries were with cephalic presentation and six patients received oxytocin for induction or acceleration of labour. Episiotomy was done in 6 patients and instrumental delivery was performed in 3 patients. Gross haematuria immediately after delivery was the most common presentation, followed by urinary incontinence. Flank pain and fever were associated with ureteric injury and were delayed for few days. Urological injury should be suspected after vaginal delivery in females with previous caesarian section, if instrumental delivery is applied, and in patients with deep vaginal tears. The presence of gross haematuria, incontinence and flank pain should indicate full urological evaluation.

Are multiple cesarean sections safe?

To assess the maternal and neonatal risk associated with high-order cesarean sections, a case-control study was carried out in two university affiliated maternity wards. The outcome of 154 pregnancies of women undergoing cesarean section for the 4th time or more was compared with 148 women sectioned for the 2nd or 3rd time and 132 women of similar age and parity after spontaneous birth. The main outcome measures were maternal operative and postoperative morbidity and neonatal prematurity and its complications, Apgar scores, and the need for intensive care. Women undergoing multiple (> or = 4) cesarean sections had significantly more intra-abdominal adhesions (P < 0.0001) than women sectioned for the 2nd or 3rd time. However, the time interval from incision to delivery and the total duration of operation were similar. The postoperative course was not adversely affected by multiple cesarean sections. A high incidence (16.2%) of preterm cesarean deliveries was noted in the study group. This was due to non-elective repeat cesarean delivery rather than to poor timing of scheduled cesarean sections. The significantly increased (P < 0.05) need for neonatal intensive care was explained by the higher occurrence of prematurity. Low Apgar scores (< or = 7) at 1 and 5 min were significantly (P < 0.01) related to multiple cesarean sections, even after controlling for the effect of gestational age. We conclude that multiple cesarean sections pose little risk for the mother, but may be associated with increased neonatal risk, attributed mainly to preterm non-elective cesarean sections.

Risk factors associated with low Apgar scores in a low-income population

The purpose of this study was to identify risk factors associated with Apgar scores of less than 7 in newborns scored at 5 minutes after birth. All newborns were delivered at Grady Memorial Hospital, Atlanta, Georgia, which primarily serves a low-income population. The data were obtained from the obstetric discharge records for 1985-89. In this case-control study, 939 newborns with Apgar scores of less than 7 were compared with 2817 newborns with Apgar scores of 7 or higher. Low birthweight (< 2500 g) and short gestational age (< 37 weeks) were each significantly associated with low Apgar scores. Race was not a significant risk factor for low Apgar scores in this low socio-economic population. It is also demonstrated that maternal risk factors (pregnancy-induced hypertension, prolonged rupture of membranes), method of delivery (caesarean, repeat caesarean, vaginal birth after caesarean section) and male sex were significantly associated with Apgar scores of less than 7. As a result of the risks that were found to be associated with method of delivery, further study of the risks associated with caesarean delivery and of the relative advantage of a caesarean delivery versus vaginal delivery after a previous caesarean section is advocated.

Uterine rupture during trial of labor after previous cesarean section

This study was undertaken to determine the incidence and associations of uterine rupture and dehiscence with an attempted vaginal birth after cesarean section. The charts from 137 patients who had uterine scar separation after a previous cesarean section from 1983 to 1989 were examined. Approximately 9.3% of the 119,395 women who were delivered in that interval had a prior cesarean section. Of those, 68.8% underwent a trial of labor with a 79.2% success rate. The uterine rupture rate in this latter group was 0.8%, while an additional 0.7% had a bloodless dehiscence. Bleeding and pain were unlikely findings with a uterine scar separation (3.4% and 7.6%, respectively). The most common manifestation of a scar separation was a prolonged fetal heart rate deceleration leading to operative intervention (70.3%). We conclude that, although the incidence of uterine rupture was low, the event is most often seen as an acute emergency. Prevention should be directed toward timely diagnosis and prompt management of labor dystocias. Staff and facilities for safe management of a uterine scar separation are a requisite for the conduct of a vaginal birth after previous cesarean section.

Rupture of the uterus in labour. An unusual case followed with sonography

In this case report a 27-year-old parturient with a previous caesarean section was diagnosed as having had a uterine rupture in labour. The diagnosis was based on the sonographic demonstration of considerable amounts of free fluid in the abdomen 2 h postpartum, and confirmed by finding fetal skin cells in this fluid. There was no hemorrhage and the fluid disappeared overnight. She was managed expectantly and made a rapid and full recovery.

Catastrophic complications of previous cesarean section

Of 711 patients who were delivered after one or more previous cesarean sections, 17 (2.4%) had an extremely serious complication. Uterine rupture and placenta previa or placenta accreta with accompanying hemorrhage were the major contributors to mortality and major morbidity. Nine uterine ruptures occurred, including five associated with labor with a low transverse uterine scar and one with an unknown scar (1.4% of trials of labor). There were two cases of placenta previa and five with varying degrees of placenta accreta. The nature and frequency of the observed complications emphasize the potentially serious remote consequences of cesarean section.