Low Transverse Cesarean Research Articles

Vaginal birth after previous cesarean delivery

A trial of labor after previous cesarean delivery has been accepted as a way to lower the overall cesarean delivery rate. In 1995, 27.5% of women who had a previous cesarean delivery attempted vaginal birth; some clinicians believe that an even higher percentage is possible (1). Although there is a strong consensus that trial of labor is appropriate for most women who have had a previous low-transverse cesarean delivery, increased experience with vaginal birth after cesarean delivery (VBAC) indicates there are several potential problems. This document will review the current risks and benefits of VBAC in various situations and provide practical management guidelines.

Weekly administration of prostaglandin E 2 gel compared with expectant management in women with previous cesareans

Objective: To compare the clinical effectiveness and safety of outpatient administration of intracervical prostaglandin (PG) E 2 gel with expectant treatment for women desiring vaginal births after cesareans. Methods: This was a randomized, multicenter investigation involving term pregnant women who each had one previous low-transverse cesarean and an unfavorable cervix (Bishop score no more than 6), and who was a candidate for vaginal delivery. They were assigned to receive 0.5 mg of PGE 2, (Prepidil; Pharmacia-Upjohn, Kalamazoo, MI) intracervically at 39 weeks’ gestation, repeated at weekly office visits for up to three doses, or expectant treatment. The main outcome variable was vaginal birth. Results: Of 294 cases, 143 received gel and 151 were treated expectantly. No differences between groups were found for maternal age, race, or Bishop score. Compared with the expectant treatment group, the PGE 2 gel group was not more likely to deliver sooner or vaginally (57% versus 55%, P = .68). The onset of labor, duration of labor among those delivering vaginally, and 1- and 5-minute Apgar scores were not different between groups. No uterine ruptures occurred, and adverse effects were equally likely in both groups. Conclusion: Although its safety was confirmed for outpatient use, weekly doses of intracervical PGE 2 did not improve the likelihood of vaginal births after cesareans.

Vereinfachter Wundverschluß bei Sectio caesarea

Fragestellung: Ist eine Vereinfachung des Wundverschlusses bei Sectio caesarea vorteilhaft und sicher?

Elective repeat cesarean delivery vs trial of labor: a comparison of morbidities in a community hospital setting

Objective: In an attempt to reduce the cesarean delivery rate nationally, many obstetricians are offering a trial of labor to their patients who have had a prior low transverse cesarean delivery. Many studies have demonstrated the success and safety of a vaginal birth after cesarean. However, few studies have actually compared elective repeat cesareans with a trial of labor. Recent articles suggest that the morbidities associated with a failed trial of labor (TOL) may be more serious than that associated with an elective repeat cesarean delivery (RC/D). Our objective was to review and compare the morbidities and complications of repeat elective cesarean delivery versus patients attempting a trial of labor in our institution. Methods and Materials: A retrospective or nonconcurrent cohort study was conducted. Inclusion criteria included all women at our institution who had delivered from July 1993 through March 1997 and had a prior cesarean delivery. Patients were eligible for a trial of labor according to the recommendations of ACOG Practice Patterns. Exclusion criteria were nonvertex presentation, prior classical or T-incision, placenta previa, previous myomectomy, or multiple gestation. The patients were divided into those who underwent an elective repeat delivery and those who consented to a trial of labor. Outcomes studied included major complications (uterine rupture or operative injury) and minor complications (puerperal fever, postpartum hemorrhage requiring transfusion or operative intervention, or abdominal wound infection). Data were ascertained from medical records, the delivery log book, and the Quality Improvement data base. Prior to performing this study, a power analysis was conducted using an alpha of 0.05 and beta of 0.20. The required number in each arm was 2,280 to determine a 50% difference in outcome. Results: There were 1,148 women who had a repeat cesarean delivery during the study time period. Of that, 174 were excluded by the criteria, leaving 973 eligible. There were 1,030 women who underwent a trial of labor. Seven hundred seventy-three women successfully delivered vaginally (75%). The overall maternal morbidity was 2.4%; 0.8% had a major complication and 1.5% had a minor complication. The total complication rate was similar for both the trial of labor group (TOL) and the elective repeat cesarean delivery group (RC/D): 2.33% and 2.57%, respectively. However, major complications were more frequent among those that attempted a trial of labor than those who underwent an elective repeat cesarean delivery; 1.65% versus 0.1% (relative risk 16.08 with a 95% CI of 2.14–120.57; P = .00024). The relative risk for minor complications in the TOL group compared to the RC/D group was 0.28 with a 95% CI 0.12–0.64 ( P = .001). Stratified analysis of the TOL group was performed. Compared to the RC/D group, those who failed VBAC had a relative risk for major complications of 56.85 using a 95% CI of 7.45–428.37. The successful VBAC group did not have statistically higher major complication rate (RR = 2.52, CI 0.23–27.74, P = .4). Conclusions: At our institution, there is a trend that major maternal complications are more frequent among those who have a trial of labor compared to those who have an elective repeat cesarean delivery. This trend was even more evident in those who failed a VBAC trial. When VBAC was successful, complications did not seem to be higher than repeat cesarean delivery. Our study did not have the power because of insufficient numbers in each arm. However, data collection is continuing to achieve the power to this study. This prompted us to reconsider the safety for a trial of labor. Perhaps more stringent criteria for selection of VBAC candidates and determination of when a trial of labor should be abandoned need to be defined. Ongoing study is warranted in this area.

Vaginal birth after cesarean delivery: a group practice’s approach to minimizing failed trial of labor

Objective: Among women attempting a trial of labor (TOL) after a prior abdominal delivery, 60–80% accomplish a vaginal birth after cesarean (VBAC). McMahon and coworkers (N Engl J Med, 1996) have indicated that at a 60% success level for TOL, the remaining 40% incurred enough major complications that the scheduled repeat cesarean section group was less morbid overall. The same authors speculated that a success rate of 80% might be necessary for the TOL group’s morbidity to be superior. We sought to review our group’s patient selection experience during an interval when successful TOL consistently exceeded 80%. Methods: The study interval ranged from January 1995 through June 1997 and was limited to patients with one previous low transverse cesarean section. Rather than using administrative or charge-related diagnoses, we analyzed a departmental database that included each delivering physician’s selection of one of four VBAC categories: successful VBAC, unsuccessful VBAC, patient declined trial of labor, or physician advised against trial of labor. All deliveries were at a single institution and were performed by one of seven obstetricians in a group practice. Results: During the study interval, 332 women provided a history of a single previous cesarean delivery. Of these 332, a total of 173 attempted a TOL and 150 of the 173 (87%) were successful. Fifty-eight of the 332 (18%) declined a trial of labor despite being assessed as excellent candidates, and 101 (30%) were advised against a TOL by their physician. Most common reasons for physicians discouraging labor included malpresentation, fetal macrosomia, and clinically small pelvis. Complications for the 23 of 173 (13%) experiencing a failed TOL included 1 asymptomatic partial separation of a uterine scar and 4 cases of puerperal fever; neither transfusion nor hysterectomy was required. Conclusions: This study demonstrates that in a population of women with one prior cesarean delivery, it is possible for a group practice to achieve a TOL success rate exceeding 80%. In our opinion the managing physician selecting out those patients least likely to attain a successful TOL contributes to a low failed TOL rate. We speculate that an analysis for best practice patterns within our group might reveal information of value for future practice guidelines.

Attempted vaginal birth after cesarean section: a multicenter comparison of outpatient prostaglandin E 2 gel with expectant management

Objective: To compare the clinical effectiveness and safety of outpatient administration of an intracervical prostaglandin (PG) E 2 gel with expectant management for women with an unfavorable cervix who wish to attempt a vaginal birth after cesarean section. Study Design: This outpatient study was a randomized, multicenter investigation involving pregnant women at term with one previous low transverse cesarean section. Each had an unfavorable cervix (Bishop score ≤4) and was a candidate for vaginal delivery. Those randomly assigned to receive the gel, rather than expectant management, were given a 0.5 mg dose of PGE 2 (Prepidil) intracervically at 39 weeks gestation. This cervical ripening treatment was repeated at weekly office visits for up to 3 doses. Results: Of the 294 cases, 143 received the gel while 151 underwent expectant management. No differences between the two groups were found for maternal demographics, race, parity, or predose Bishop score. The rates of repeat cesarean section did not differ ( P = .68) with use of the gel (61, 42%) or with expectant therapy (48, 45%). The onset of active labor, the duration of labor among those delivering vaginally, and the 1-minute and 5-minute Apgar scores were not different between the two groups. No uterine rupture was apparent, and adverse effects during labor were as likely to occur in the two groups. Conclusions: Although its safety was confirmed for outpatient use and for persons with a prior cesarean delivery, intracervical prostaglandin E 2 gel did not improve the chance of a vaginal birth after a cesarean delivery.

Trial of labor or repeated cesarean section. The woman's choice.

To develop recommendations for the preferred delivery method for a pregnant woman who underwent a previous low transverse cesarean section and who has no contraindications to labor. MEDLINE searches and the references from retrieved articles yielded 759 citations. Search terms included trial of labor (TOL), trial of scar, vaginal birth after cesarean section (VBAC), and uterine rupture. Articles with primary outcomes data contrasting TOL and elective repeat cesarean section (ERCS) were analyzed. Studies from developing countries or before 1980 were excluded. Data from 292 articles were extracted independently by at least 2 team members using a structured form. Outcome data were combined using commercially available software and are presented as absolute differences per 10,000, with 95% Bayesian confidence intervals. Maternal outcomes showed that TOL increased the risk for uterine rupture (23.9 [0.24%]); ERCS increased the risk for infection (522 [5.22%]) and bleeding (58.6 [0.59%]). Infant outcomes differed only for 5-minute Apgar scores of less than 7, which were more likely for infants whose mothers underwent TOL (85 [0.85%]). Other outcomes (eg, disability), patient preferences, and cost data did not lend themselves to meta-analysis and were examined separately. While two thirds of women desired TOL, one third preferred ERCS. Costs were 1.7 to 2.4 times greater for ERCS. A woman should be given information on both delivery methods and encouraged to undergo TOL, but her preference for ERCS should be respected.

One- versus two-layer closure of a low transverse cesarean: The next pregnancy

To determine whether a low transverse cesarean closure method in one or two layers affects subsequent pregnancy outcome. In a prospective trial reported previously, 906 women were assigned randomly to either one- or two-layer uterine closure. One hundred sixty-four women had a subsequent pregnancy and delivery (18 weeks' gestation or longer) at our institution. Maternal and neonatal outcomes were ascertained by medical chart review and compared between the one- and two-layer closure groups. Of the 164 subsequent deliveries, 83 had previous closure in one layer, whereas 81 had involved a two-layer closure. The demographic characteristics of these two groups were similar. Nineteen women (12%) underwent elective repeat cesareans without labor, and the remaining 145 experienced labor. Length of labor, mode of delivery, duration of hospital stay, gestation at delivery, and the incidences of uterine scar dehiscence, chorioamnionitis, postpartum metritis, hemorrhage, transfusion, and abnormal placentation did not differ significantly between the groups. Selected neonatal outcomes, including Apgar scores, cord pH, birth weight, and perinatal death, were similar between groups as well. These findings suggest that the type of low transverse cesarean closure does not significantly affect the outcome of the next pregnancy.

Closure or nonclosure of the visceral peritoneum at cesarean delivery

OBJECTIVE: Our purpose was to determine whether nonclosure of the visceral peritoneum at low transverse cesarean delivery has advantages over suture peritonization with regard to postoperative morbidity. STUDY DESIGN: A prospective randomized trial of 549 women undergoing cesarean section was carried out; 262 were randomized to nonclosure and 287 to closure of the visceral peritoneum. Perioperative, intraoperative, and postoperative management decisions were made without reference to treatment groups. Statistical analysis compared intraoperative and postoperative outcome between the two groups. RESULTS: Operating and anesthesia times were significantly shorter in patients receiving nonclosure. The incidence of febrile morbidity and cystitis and the need for antibiotics and narcotics were all significantly greater when the peritoneum was closed. Hospital stay was significantly shorter after nonclosure. CONCLUSION: Nonclosure of the visceral peritoneum is associated with lower febrile and infectious morbidity. Routine closure of the visceral peritoneum should be abandoned at cesarean delivery. (AM J OBSTET GYNECOL 1996;174:1366-70.)

T and J vertical extensions in low transverse cesarean births

To determine the frequency of T and J extensions in low transverse cesarean births at a regional perinatal center, identify the indications for these incisions, and evaluate the associated complications. We reviewed the medical records of 56 patients delivered between January 1988 and November 1994 by low transverse cesarean birth requiring vertical extension of the incision into-the upper uterine segment. Cases of extension were compared with controls matched for gestational age, presentation, and indication for cesarean delivery. Data collected included demographic information, indications for extension, extension type, estimated blood loss, intraoperative complications, and length of hospital stay. Paired Student t test and McNemar test were used for statistical analysis. Vertical extensions were performed in 1.3% (95% confidence interval 0.42-2.26%) of low transverse incisions over a 7-year period. The most common indications were malpresentation (n = 31), poorly developed lower uterine segment (n = 12), and fetal head deeply arrested in the midpelvis (n = 6). Estimated blood loss was greater for patients requiring an extension (990 +/- 310 mL) compared with controls (790 +/- 150 mL), as were differences in preoperative versus postoperative hemoglobin and hematocrit (P < .05). Surgical complications were observed in 28 of 56 (50%) subjects with a uterine extension, including excessive blood loss (n = 20), broad ligament hematomas or extensions (n = 4), cervical lacerations (n = 4), and uterine artery lacerations (n = 4). Patients with vertical extensions also had longer hospital stays (4.6 +/- 1.6 versus 3.8 +/- 1.1 days) (P < .05). Low transverse uterine incisions may be inadequate for the safe delivery of a fetus in cases of malpresentation, preterm birth, and poor development of the lower uterine segment. Used to complete these difficult deliveries, T and J extensions are often associated with intraoperative complications and prolonged hospital stays compared with controls.

Labor induction in patients with previous cesarean section.

To determine the efficacy and safety of labor induction in patients previously delivered by at least one low transverse cesarean section, a retrospective review was done at a single tertiary perinatal center, the University of Florida Health Science Center, Jacksonville. All patients with a previous cesarean section who required labor induction from 1988 until the end of 1992 were identified. Duration and outcome of labor induction, including mode of delivery, maternal and perinatal morbidity, and birth trauma, were evaluated. Of 160 patients with a previous cesarean, 50 (31.3%) had a repeat operation compared to 18 (11.2%) in the no previous cesarean group (p = 0.001, odds ratio = 3.59; 95% confidence interval, 1.98, 6.49). Women in the cesarean group had a higher incidence of operative vaginal deliveries, prolonged duration of the first and second stages of labor, rate and maximum dose of oxytocin infusion. One patient in the previous cesarean group experienced uterine rupture. There was no difference in the rate of infants with low 5-minute Apgar scores or with cord pH values less than 7.20. Labor induction in women with previous low transverse cesarean sections results in an acceptable rate of vaginal delivery and appears safe for both mother and fetus.

Cesarean delivery: A reconsideration of terminology

The terminology we employ influences our perceptions. Thus, we believe in reviewing terminology regularly. The term "cesarean section" should be abandoned. A medical procedure is rarely named after a historic figure, and almost never after an ancient Roman law. Cesarean section has recently been amended to cesarean birth; however, the term is still inadequate. The word "hysterotomy" more appropriately describes the procedure we regularly perform. The adjectives used to describe cesarean birth should also be reevaluated. If we are to keep the term "classical" for the original fundal vertical uterine incision, then the other designations of hysterotomy should retain the same architectural context. Contemporary hysterotomy should be used in reference to a low transverse cesarean. Neoclassical hysterotomy might be used to describe the low vertical procedure. Transitional hysterotomy may be an appropriate term for the "hockey stick" or "J" incision. Cesarean delivery best describes a postmortem cesarean. Vaginal birth after cesarean (VBAC) is inappropriate because a vaginal birth after a cesarean section would not occur if cesarean section refers to a perimortem procedure. Vaginal birth after hysterotomy should be substituted for VBAC. Such revision of our terminology will keep obstetrics at the forefront of medical science and bring us most efficiently into the 21st century.

Cervical Ripening in Women With Previous Cesarean Deliveries

Objective: To evaluate the safety and efficacy of preinduction cervical ripening in women with previous cesarean deliveries undergoing induction of labor. Methods: Retrospective study of women with previous low transverse cesarean deliveries who underwent ripening of an unfavorable cervix prior to induction of labor (n = 89). Multiparas without previous cesarean deliveries undergoing ripening and induction of labor during the same time period were used for comparison (n = 61). Ripening was performed with prostaglandin E2 (PGE2) gel, or an osmotic dilator, or both. Induction of labor with oxytocin followed the American College of Obstetricians and Gynecologists' guidelines. Outcome data were analyzed using the unpaired Student's t-test or χ2-test as appropriate. Significance was established at P < 0.05. Results: The mean gestational age was 39.6 ± 2.6 and 38.2 ± 2.9 weeks for the study and comparison groups, respectively. There were no differences between the groups in Bishop score, duration of the first stage of labor, maximum dose of oxytocin, indications for cesarean delivery, puerperal morbidity, birthweight, Apgar scores or NICU admissions. Sixty-four percent (57 of 89) of study women delivered vaginally compared with 82% (50 of 61) of women in the comparison group (P < 0.03). The data were analyzed separately for those women undergoing cervical ripening with PGE2 gel only. No differences were observed between the groups in any of the categories mentioned above. Conclusion: Cervical ripening appears to be safe and effective in women with previous low transverse cesarean deliveries undergoing induction of labor with an unfavorable cervix.

T and J uterine incision in low transverse cesarean births (LTCB): [formula omitted]x, S. Gabbe. Dept. Ob/Gyn, The Ohio State University Med. Center, Columbus, OH

T and J uterine incision in low transverse cesarean births (LTCB): [formula omitted]x, S. Gabbe. Dept. Ob/Gyn, The Ohio State University Med. Center, Columbus, OH

Cervical ripening in women with previous cesarean deliveries

Objective: To evaluate the safety and efficacy of preinduction cervical ripening in women with previous cesarean deliveries undergoing induction of labor. Methods: Retrospective study of women with previous low transverse cesarean deliveries who underwent ripening of an unfavorable cervix prior to induction of labor ( n = 89). Multiparas without previous cesarean deliveries undergoing ripening and induction of labor during the same time period were used for comparison ( n = 61). Ripening was performed with prostaglandin E 2 (PGE 2) gel, or an osmotic dilator, or both. Induction of labor with oxytocin followed the American College of Obstetricians and Gynecologists' guidelines. Outcome data were analyzed using the unpaired Student's t-test or χ 2-test as appropriate. Significance was established at P < 0.05. Results: The mean gestational age was 39.6 ± 2.6 and 38.2 ± 2.9 weeks for the study and comparison groups, respectively. There were no differences between the groups in Bishop score, duration of the first stage of labor, maximum dose of oxytocin, indications for cesarean delivery, puerperal morbidity, birthweight, Apgar scores or NICU admissions. Sixty-four percent (57 of 89) of study women delivered vaginally compared with 82% (50 of 61) of women in the comparison group ( P < 0.03). The data were analyzed separately for those women undergoing cervical ripening with PGE 2 gel only. No differences were observed between the groups in any of the categories mentioned above. Conclusion: Cervical ripening appears to be safe and effective in women with previous low transverse cesarean deliveries undergoing induction of labor with an unfavorable cervix.

Spontaneous Rupture of a Low Transverse Cesarean Scar

Uterine rupture occurs in less than 1% of pregnancies. The literature over the past several years confirms the safety of the low transverse uterine scar. We report a case of spontaneous rupture of a low transverse cesarean scar at 36 weeks' gestation, resulting in fetal death.

Trial of labor after a one- or two-layer closure of a low transverse uterine incision

In the subsequent labor and delivery of 292 women who had a prior low transverse cesarean section the incidence of scar separation was low and was not affected by the method of uterine closure. A low transverse incision closed in one continuous layer should not preclude a subsequent trial of labor.

Amyl nitrite: use as a smooth muscle relaxant in difficult preterm cesarean section.

Amyl nitrite is a smooth muscle relaxant that has been used clinically to facilitate uterine relaxation in difficult deliveries. In this retrospective study, we evaluate the safety of amyl nitrite use during preterm cesarean deliveries, and we assess possible advantageous effects on surgical incision choice. Women who received amyl nitrite cesarean section were compared to a control group matched for gestational age, fetal presentation, and mode of delivery who did not receive amyl nitrite. There were no statistical differences between the groups in the independent variables (maternal age, parity, medical or obstetric history, type of anesthesia, anesthesia or obstetric attending physician, antepartum hematocrit, or neonatal weight). Outcome (dependent) variables (estimated blood loss, Apgar scores, postpartum hematocrit, cord gases, or postpartum complications) were assessed, and there were no significant differences between the groups. Low transverse cesarean section was performed more frequently in the amyl nitrite group (58 of 64) than in the comparison group (48 of 64) (p less than 0.03). Considering the 128 women with and without amyl nitrite together, the decrease in hematocrit observed postpartum was greater after classic section (7%) than after low transverse section (4%) (p less than 0.002). We conclude that the use of amyl nitrite during preterm cesarean section poses no threat to mother or fetus and may facilitate delivery by allowing the performance of a low transverse rather than a classic cesarean section without maternal or neonatal complications.

Performance of Cesarean Section Using Absorbable Staples

Although stapling techniques have gained wide acceptance in general surgery, they are still not commonly used in obstetrics. U.S. Surgical Corporation has introduced a stapling device suitable for use in cesarean sections. The copolymer staples (a blend of polylactic and polyglycolic acids) maintain their tensile strength until healing occurs and absorb without producing granulation tissue. The benefits include minimal trauma to tissue and reduced operating time, blood loss and postoperative morbidity. From July 1988 to February 1989, all patients undergoing low transverse cervical cesarean sections were randomized to either group 1 with the uterine incision performed in a routine manner or group 2 with the uterine incision cut and stapled using the Stapler. The preoperative management, intraoperative technique and postoperative surveillance were similar for both groups. The uterine incision was assessed by pelvic sonography during the postpartum period. Statistical analysis was performed using Fisher's exact test and chi-square analysis. Both groups were comparable for age, race, parity, gestational age and primary diagnosis. The length of the operative procedure was significantly shorter (p less than 0.05) in the stapled group. These patients also had a statistically significantly decreased incidence of uterine incisions and lacerations. All other parameters were not significantly different in the two groups. The stapled uterine incisions were visible by ultrasonography in more patients in the stapled group throughout the postpartum period than in the sutured group. Thus, stapling of the uterine incision was an acceptable alternative to traditional suturing techniques and it was possible to visualize clearly these incisions during the postpartum period.

External cephalic version after previous cesarean section

Approximately 100,000 cesarean sections are performed each year in the United States because of breech presentation. Numerous studies have shown that external cephalic version can eliminate the need for many of these operations. However, because of the fear of uterine rupture, these studies have generally excluded patients who have undergone previous cesarean section. To evaluate the validity of this exclusion policy, we studied patients with one or more previous cesarean sections and breach presentations near term. Version attempts were successful in 82% of 56 patients who had undergone a previous cesarean section. Sixty-five percent of the successful version patients went on to have vaginal birth after cesarean section. There were no serious maternal or fetal complications associated with the version attempts. We conclude that external cephalic version is a reasonable option in patients with prior low transverse cesarean section.