Uterine rupture during a trial of labor in a case with a unicornuate uterus and a previous cesarean section

Maternal and neonatal outcomes after uterine rupture in labor

OBJECTIVE

There is significant controversy about the risks related to attempted vaginal birth after cesarean and the implications for informed consent of the patient. Recent data suggest that women who deliver in hospitals with high attempted vaginal birth after cesarean rates are more likely to experience successful vaginal birth after cesarean, as well as uterine ruptures. We conducted a study to evaluate maternal and neonatal morbidity and mortality after uterine rupture at a tertiary care center.

STUDY DESIGN

We performed a retrospective chart review of cases of uterine rupture from 1976 to 1998. All women who had a history of uterine rupture were identified with International Classification of Diseases, Ninth Revision, identifiers with hospital discharge data cross-referenced with a separate obstetric database. We abstracted demographic information, fetal heart rate patterns, maternal pain and bleeding patterns, umbilical cord gas values, and Apgar scores from the medical record. Outcome variables were uterine rupture events and major and minor maternal and neonatal complications.

RESULTS

During the study period there were 38,027 deliveries. The attempted vaginal birth after cesarean rate was 61.3%, of which 65.3% were successful. We identified 21 cases of uterine rupture or scar dehiscence. Seventeen women had prior cesarean deliveries (10 with primary low transverse cesarean delivery, 3 with unknown scars, 1 with classic cesarean delivery, 2 with two prior cesarean deliveries, and 1 with four prior cesarean deliveries). Of the 4 women who had no history of previous uterine surgery, one had a bicornuate uterus whereas the others had no factors increasing the risk for uterine rupture. We confirmed uterine rupture and scar dehiscence in 19 women. Specific details were not available for 2 patients. Uterine rupture or scar dehiscence was clinically suspected in 16 women with 3 cases identified at delivery or after delivery. Sixteen women had symptoms of increased abdominal pain, vaginal bleeding, or altered hemodynamic status. There were 2 patients who required hysterectomies and 3 women who received blood transfusions; there were no maternal deaths related to uterine rupture. The fetal heart rate pattern in 13 cases showed bradycardia and repetitive variable or late decelerations. Thirteen neonates had umbilical artery pH >7.0. Two cases of fetal or neonatal death occurred, one in a 23-week-old fetus whose mother had presented to an outlying hospital and the second in a 25-week-old fetus with Potter's syndrome. All live-born infants were without evidence of neurologic abnormalities at the time of discharge.

CONCLUSION

Our data confirm the relatively small risk of uterine rupture during vaginal birth after cesarean that has been demonstrated in previous studies. In an institution that has in-house obstetric, anesthesia, and surgical staff in which close monitoring of fetal and maternal well-being is available, uterine rupture does not result in major maternal morbidity and mortality or in neonatal mortality.

Incidence of uterine rupture among women with müllerian duct anomalies who attempt vaginal birth after cesarean delivery

OBJECTIVE

The purpose of this study was to determine and compare the incidences of uterine rupture among women with and without müllerian duct anomalies who were attempting vaginal birth after cesarean delivery.

STUDY DESIGN

There were 1813 attempts at vaginal birth after cesarean delivery between 1992 and 1997 at the Foothills Hospital in Calgary, Alberta, Canada. Of the patients 25 had known müllerian duct anomalies and 1788 did not. The records of these 1813 women were reviewed with respect to uterine rupture, other complications, mode of delivery, and characteristics of the trial of labor. Comparisons were made with the Fisher exact test.

RESULTS

The rates of uterine rupture were 8% (2/25) in the group with müllerian duct anomalies and 0.61% (11/1788) in the group without müllerian duct anomalies (P =.013). The cesarean delivery rates were 20% (5/25) and 25.1% (448/1788), respectively. All cesarean deliveries among women with müllerian duct anomalies were performed urgently in response to severe fetal heart rate abnormalities. The rates of fetal heart rate abnormalities necessitating immediate delivery (60% vs 14.1%, P =.013), operative vaginal delivery (40% vs 19.6%, P =.02), and cord prolapse (8% vs 0.45%, P =.0076) were significantly greater in the group with müllerian duct anomalies.

CONCLUSIONS

Vaginal delivery is common among women with müllerian duct anomalies who attempt vaginal birth after cesarean delivery, but the rates of uterine rupture and other complications are high.