Maternal morbidity associated with cesarean delivery without labor compared with spontaneous onset of labor at term

OBJECTIVE: To estimate the maternal morbidity associated with cesarean deliveries performed at term without labor compared with morbidity associated with spontaneous labor. METHODS: A 14-year, population-based, cohort study (1988-2001) using the Nova Scotia Atlee Perinatal Database compared maternal outcomes in nulliparous women at term undergoing spontaneous labor for planned vaginal delivery with singleton, cephalic presentation and nulliparous women delivering by cesarean without labor. RESULTS: From a total of 18,435 pregnancies, which satisfied inclusion and exclusion criteria, 721 were cesarean deliveries without labor. There were no maternal deaths or transfers for intensive care. There was no difference in wound infection, blood transfusion, or intraoperative trauma. Women undergoing cesarean deliveries without labor were more likely to have puerperal febrile morbidity (relative risk [RR] 2.2; 95% confidence interval [CI] 1.1, 4.5; P=.03), but were less likely to have early postpartum hemorrhage (RR 0.6; 95% CI 0.4, 0.9; P=.01) compared with women entering spontaneous labor. Subgroup analyses of maternal outcomes in women delivering by spontaneous and assisted vaginal delivery and cesarean delivery in labor were also performed. The highest morbidity was found in the assisted vaginal delivery and cesarean delivery in labor groups. CONCLUSION: The increased maternal morbidity in elective cesarean delivery compared with spontaneous onset of labor is limited to puerperal febrile morbidity. Maternal morbidity is increased after assisted vaginal delivery and cesarean delivery in labor compared with cesarean delivery without labor.     

Cervical ripening with transcervical foley catheter and the risk of uterine rupture

OBJECTIVE: To estimate whether the rate of uterine rupture in patients with a previous cesarean delivery is related to labor induction and/or cervical ripening using transcervical Foley catheter. METHODS: Charts of all patients who had a trial of labor after a previous cesarean delivery in our institution between 1988 and 2002 were reviewed. The rates of successful vaginal birth after cesarean delivery and uterine rupture in patients with spontaneous labor (control group) were compared with those of patients who underwent a labor induction by means of amniotomy with or without oxytocin and patients who underwent a labor induction/cervical ripening using a transcervical Foley catheter. Logistic regression analysis was performed to adjust for confounding variables. RESULTS: Of 2479 patients, 1807 had a spontaneous labor, 417 had labor induced by amniotomy with or without oxytocin, and 255 had labor induced by using transcervical Foley catheter. The rate of successful vaginal birth after cesarean delivery was significantly different among the groups (78.0% versus 77.9% versus 55.7%, P <.001), but not the rate of uterine rupture (1.1% versus 1.2% versus 1.6%, P =.81). After adjusting for confounding variables, the odds ratio (OR) for successful vaginal birth after cesarean delivery was 0.68 (95% confidence interval [CI] 0.41, 1.15), and the OR for uterine rupture was 0.47 (95% CI 0.06, 3.59) in patients who underwent an induction of labor using a transcervical Foley catheter when compared with patients with spontaneous labor. CONCLUSION: Labor induction using a transcervical Foley catheter was not associated with an increased risk of uterine rupture.     

Vaginal birth after cesarean: to induce or not to induce

OBJECTIVE: Our purpose was to determine the impact of labor induction on both the success and safety of a trial of labor in women who are candidates for vaginal birth after cesarean. STUDY DESIGN: We performed a prospective observational analysis of 505 women consecutively presenting for delivery with a prior cesarean (September 1997-December 1999), of whom 236 (46.7%) underwent trial of labor. The following three cohorts were established: (1) repeat cesarean without trial of labor (n = 269), (2) spontaneous trial of labor (n = 179), and (3) induced trial of labor (n = 57). RESULTS: The vaginal delivery rate was significantly higher (77.1% vs 57.9%) in the spontaneous labor group compared with the induced labor group (odds ratio, 2.45; 95% confidence interval, 1.24-4.82; P =.008). Uterine scar separation occurred more frequently in the induced labor group (7%) than in the elective repeat cesarean group (1.5%) (odds ratio, 0.20; 95% confidence interval, 0.04-0.99; P =.034). CONCLUSION: Induction of labor in women attempting vaginal birth after cesarean is associated with a significantly reduced rate of successful vaginal delivery and an increased risk of serious maternal morbidity.     

Spontaneous versus induced labor after a previous cesarean delivery

OBJECTIVE: To compare maternal and neonatal outcomes in spontaneous versus induced labor after one previous cesarean delivery. METHODS: Women with one previous cesarean delivery who had spontaneous labor between January 1992 and January 2000 were compared with those whose labor was induced. RESULTS: Three thousand seven hundred forty-six patients had a trial of labor (2943 spontaneous, 803 induced). Those induced had more frequent early postpartum hemorrhage (7.3% versus 5.0%; odds ratio [OR] 1.66; 95% confidence interval [CI] 1.18, 2.32), cesarean delivery (37.5% versus 24.2%; OR 1.84; 95% CI 1.51, 2.25), and neonatal intensive care unit (NICU) admission (13.3% versus 9.4%; OR 1.69; 95% CI 1.25, 2.29). There was a trend toward higher uterine rupture rates in those with induced versus spontaneous labor (0.7% versus 0.3%, P =.128) and for patients undergoing dinoprostone (prostaglandin E(2)) induction versus other methods (1.1% versus 0.6%, P =.62), although neither difference achieved statistical significance. CONCLUSION: Induced labor is associated with an increased rate of early postpartum hemorrhage, cesarean delivery, and neonatal ICU admission. The higher rate of uterine rupture in those who had labor induced was not statistically significant.     

Vaginal birth after cesarean delivery: an historic cohort cost analysis

OBJECTIVE: The purpose of this study was to evaluate the relative cost-effectiveness of attempted vaginal birth after cesarean delivery compared with elective repeat cesarean delivery. STUDY DESIGN: We performed an historic cohort analysis of women with a single prior cesarean delivery who were delivered at our institution during 1999. Inclusion criteria were > or =36 weeks' gestation and carrying a live, singleton fetus with no antenatally diagnosed anomalies. The primary outcome variable was mean cost of hospital care for mother-infant pairs, as obtained from the hospital's Clinical Resources Department. RESULTS: The cohort consisted of 204 mother-infant pairs, 65 in the elective repeat cesarean group and 139 in the attempted vaginal birth group. Mean cost of care was higher for mothers ($4155 vs $3675;P <.001), neonates ($1794 vs $1187; P =.03), and mother-infant pairs ($5949 vs $4863; P =.001) for the elective repeat cesarean group compared with the attempted vaginal delivery group. CONCLUSION: In women with a single prior cesarean delivery, a trial of labor is more cost-effective than an elective repeat cesarean delivery.     

Induction of labor or serial antenatal fetal monitoring in postterm pregnancy: a randomized controlled trial

OBJECTIVE: To compare induction of labor at gestational age 41 weeks with expectant management in regard to neonatal morbidity. Secondary aims were to assess the effect of these managements on mode of delivery and maternal complications. METHODS: Between September 2002 and July 2004, postterm women with singleton cephalic presentation and no prelabor rupture of membranes were randomly assigned to induction of labor at 289 days or antenatal fetal surveillance every third day until spontaneous labor. Main outcome measures were neonatal morbidity, operative delivery rates, and maternal complications. RESULTS: Five hundred eight women were randomly assigned, 254 in each group. No differences of clinical importance were observed in women in whom labor was induced compared with women who were expectantly managed with regard to the following outcomes: neonates whose 5-minute Apgar score was less than 7 (three neonates in the induction group compared with four in the monitoring group, P=.72); neonates whose umbilical cord pH was less than 7 (three compared with two, P=.69); prevalence of cesarean delivery (28 compared with 33, P=.50); or prevalence of operative vaginal delivery (32 compared with 27, P=.49). In the induction group more women had precipitate labors (33 compared with 12, P<.01; number needed to treat was 13), and the duration of second stage of labor was more often less than 15 minutes (94 compared with 56, P<.01; number needed to treat was 7). CONCLUSION: No differences were found between the induced and monitored groups regarding neonatal morbidity or mode of delivery, and the outcomes were generally good. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00385229. LEVEL OF EVIDENCE: I.     

Maternal morbidity associated with cesarean delivery without labor compared with induction of labor at term

OBJECTIVE: To estimate the maternal morbidity associated with cesarean deliveries performed at term without labor compared with morbidity associated with induction of labor at term. METHODS: A 15-year population-based cohort study (1988-2002) using the Nova Scotia Atlee Perinatal Database compared maternal outcomes in nulliparous women delivering by cesarean delivery without labor and nulliparous women at term undergoing induction of labor for planned vaginal delivery with singleton, cephalic presentation. RESULTS: A total of 5,779 pregnancies satisfied inclusion and exclusion criteria, 879 of which were cesarean deliveries without labor. There were no maternal deaths. There was no difference in wound infection, puerperal febrile morbidity, blood transfusion or intraoperative trauma. After controlling for potential confounders, women undergoing cesarean delivery without labor were less likely to have complications of early postpartum hemorrhage (relative risk 0.61, 95% confidence interval 0.42-0.88, number needed to treat 32) and composite maternal morbidity (relative risk 0.71, 95% confidence interval 0.52-0.95, number needed to treat 34) compared with women undergoing induction of labor. Subgroup analyses of maternal outcomes after induction of labor in women by method of delivery were also performed and demonstrated additional risks of traumatic morbidity after induction of labor. The highest morbidity was found in the assisted vaginal delivery and cesarean delivery in labor groups. CONCLUSION: Early postpartum hemorrhage and composite maternal morbidity were decreased in cesarean delivery without labor compared with induction of labor. Hemorrhagic and traumatic morbidities with labor induction are increased after assisted vaginal delivery and cesarean delivery in labor compared with cesarean delivery without labor.     

Interdelivery interval and the success of vaginal birth after cesarean delivery.

OBJECTIVE: To determine whether a short interdelivery interval is associated with decreased rate of successful vaginal birth after cesarean (VBAC). METHODS: A retrospective cohort study from January 1, 1997, to December 31, 2000, was conducted. Patients with previous cesarean delivery who attempted VBAC were identified. The analysis was limited to patients at term with one prior cesarean. The interdelivery interval was calculated in months between the index pregnancy and prior cesarean delivery. RESULTS: A total of 1516 subjects who attempted VBAC were identified among 24,162 deliveries, with complete data available in 1185 cases. The VBAC success rate was 79.0% for patients with an interdelivery interval less than 19 months compared with 85.5% for patients with an interval delivery greater than or equal to 19 months (P =.12). For patients whose labors were induced, interdelivery intervals of less than 19 months were associated with a decreased rate of VBAC success when compared with longer intervals (P <.01). Sufficient power (beta =.95) existed to detect a 64% difference between the groups (alpha =.05). No significant difference was detected in women who underwent spontaneous labor (P =.98). There was no difference in the rate of symptomatic uterine rupture (P = 1.00). CONCLUSION: Interdelivery intervals of less than 19 months were associated with a decreased rate of VBAC success in patients who underwent induction, a difference not found in those with spontaneous labor.     

Uterine rupture during induced trial of labor among women with previous cesarean delivery

OBJECTIVE: This study was undertaken to compare the rates of uterine rupture during induced trials of labor after previous cesarean delivery with the rates during a spontaneous trial of labor. STUDY DESIGN: All deliveries between 1992 and 1998 among women with previous cesarean delivery were evaluated. Rates of uterine rupture were determined for spontaneous labor and different methods of induction. RESULTS: Of 2119 trials of labor, 575 (27%) were induced. The overall rate of uterine rupture was 0.71% (15/2119). The uterine rupture rate with induced trial of labor (8/575; 1.4%) was significantly higher than with a spontaneous trial of labor (7/1544; 0.45%; P =.0004). Uterine rupture rates associated with different methods of induction were compared with the rate seen with spontaneous labor and were as follows: prostaglandin E(2) gel, 2.9% (5/172; P =.004); intracervical Foley catheter, 0.76% (1/129; P =.47); and labor induction not requiring cervical ripening, 0.74% (2/274; P =.63). The uterine rupture rate associated with inductions other than with prostaglandin E(2) was 0.74% (3/474; P =.38). The relative risk of uterine rupture with prostaglandin E(2) use versus spontaneous trial of labor was 6.41 (95% confidence interval, 2. 06-19.98). CONCLUSION: Induction of labor was associated with an increased risk of uterine rupture among women with a previous cesarean delivery, and this association was highest when prostaglandin E(2) gel was used.     

Labor progression and risk of cesarean delivery in electively induced nulliparas

OBJECTIVE: To describe the pattern of labor progression and risk of cesarean delivery in women whose labor was electively induced. METHODS: We analyzed data on all low-risk, nulliparous women with an elective induction or spontaneous onset of labor between 37 + 0 and 40 + 6 weeks from January 2002 to March 2004 at a single institution. The median duration of labor by each centimeter of cervical dilation and the risk of cesarean delivery were computed for 143 women with preinduction cervical ripening and oxytocin induction, 286 women with oxytocin induction, and 1,771 women with a spontaneous onset of labor. An intracervical Foley catheter was used to ripen the cervix. RESULTS: Electively induced labor with cervical ripening had substantially slower latent and early active phases. After controlling for potential confounders, women who had an elective induction with cervical ripening had 3.5 times the risk of cesarean delivery during the first stage of labor (95% confidence interval 2.7-4.5), compared with those admitted in spontaneous labor. Elective induction without cervical ripening, on the other hand, was associated with a faster labor progression from 4 to 10 cm (266 compared with 358 minutes, P < .01) and did not increase the risk of cesarean delivery, compared with those in spontaneous labor. CONCLUSION: The pattern of labor progression differs substantially for women with an electively induced labor compared with those with spontaneous onset of labor. Furthermore, elective induction in nulliparous women with an unfavorable cervix has a high rate of labor arrest and a substantially increased risk of cesarean delivery. LEVEL OF EVIDENCE: II-2.     

Trial of labor after 40 weeks' gestation in women with prior cesarean

OBJECTIVE: To compare outcomes in women with prior cesareans delivering at or before 40 weeks' gestation with those delivering after 40 weeks. METHODS: We reviewed labor outcomes over 12 years at one institution for women with one prior cesarean and no other deliveries who had a trial of labor at term. We analyzed the rates of symptomatic uterine rupture and cesarean for term deliveries before or after 40 weeks and stratified for spontaneous and induced labor. Potential confounding by birth weight was controlled using logistic regression. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated. RESULTS: Of 2775 women with one prior scar and no other deliveries, 1504 delivered at or before 40 weeks and 1271 delivered after 40 weeks. For spontaneous labor, rupture rate at or before 40 weeks was 0.5% compared with 1.0% after 40 weeks (P =.2, adjusted OR 2.1, CI 0.7, 5.7). For induced labor, uterine rupture rates were 2.1% at or before 40 weeks and 2.6% after 40 weeks (P =.7, adjusted OR 1.1, CI 0.4, 3.4). For spontaneous labor, rate of cesareans during subsequent trials of labor at or before 40 weeks was 25% compared with 33.5% after 40 weeks (P =.001, adjusted OR 1.5, CI 1.2, 1.8). For induced labor, rate of cesareans during subsequent trials of labor at or before 40 weeks was 33.8% compared with 43% after 40 weeks (P =.03, adjusted OR 1.5, CI 1.1, 2.2). CONCLUSION: The risk of uterine rupture does not increase substantially after 40 weeks but is increased with induction of labor regardless of gestational age. Because spontaneous labor after 40 weeks is associated with a cesarean rate similar to that following induced labor before 40 weeks, awaiting spontaneous labor after 40 weeks does not decrease the likelihood of successful vaginal delivery.     

Effect of previous vaginal delivery on the risk of uterine rupture during a subsequent trial of labor

OBJECTIVE: We examined the effect of prior vaginal delivery on the risk of uterine rupture in pregnant women undergoing a trial of labor after prior cesarean delivery. STUDY DESIGN: The medical records of all pregnant women with a history of cesarean delivery who attempted a trial of labor during a 12-year period at a single center were reviewed. For the current analysis, the study population was limited to term pregnancies. The effect of previous vaginal delivery on the risk of uterine rupture during a subsequent trial of labor was evaluated. Separate analyses were performed for women with a single previous cesarean delivery and for those with >1 prior cesarean delivery. For each of these subgroups, the rate of uterine rupture among women who had > or =1 prior vaginal delivery was compared with the rate among women with no prior vaginal delivery. Logistic regression analysis was used to examine the associations with control for confounding factors. RESULTS: Of 3783 women with 1 prior scar, 1021 (27.0%) also had > or =1 prior vaginal delivery. During a subsequent trial of labor, the rate of uterine rupture was 1.1% among pregnant women without prior vaginal delivery and 0.2% among pregnant women with prior vaginal delivery (P =.01). Logistic regression analysis controlling for duration of labor, induction, birth weight, maternal age, year of birth, epidural analgesia, and oxytocin augmentation indicated that, among women with a single scar, those with a prior vaginal delivery had a risk of uterine rupture that was one fifth that of women without a previous vaginal delivery (odds ratio, 0.2; 95% confidence interval, 0.04-0.8). In the group of 143 pregnant women with >1 previous cesarean delivery, women with a prior vaginal delivery had a somewhat lower risk of uterine rupture (3.9% vs 2.5%; adjusted odds ratio, 0.6; 95% confidence interval, 0.01-6.7). This difference was not statistically significant. CONCLUSION: Among women with 1 prior cesarean delivery undergoing a subsequent trial of labor, those with a prior vaginal delivery were at substantially lower risk of uterine rupture than women without a previous vaginal delivery.     

Prolonged pregnancy: induction of labor and cesarean births

OBJECTIVE: To determine the effects of labor induction on cesarean delivery in post-date pregnancies. MATERIALS AND METHODS: A total of 1325 women who reached 41 weeks' gestation between December 1, 1997, and April 4, 2000, and who were scheduled for induction of labor at 42 weeks were included in this prospective observational study. Cesarean delivery rates were compared between those women who entered spontaneous labor and those who underwent induction. Women with any medical or obstetric risk factors were excluded. A power analysis was performed to determine how many patients would be required to show no effect of labor induction on cesarean delivery with a beta of.8 and an alpha of.05. Approximately 5200 patients would be required, taking an estimated 28 years to accrue at our institution. RESULTS: Admission to delivery was longer (5.7 compared with 11.1 hours, P =.001) and more likely to extend beyond 10 hours (55 compared with 24%, P =.001) in the induction group. Cesarean deliveries were increased in the induced group (19 compared with 14%, P <.001) due to cesarean for failure to progress (14 compared with 8%, P <.001). Independent risk factors for cesarean delivery included nulliparity, undilated cervix prior to labor, and epidural analgesia. Correction for these risk factors using logistic regression analysis revealed that it was the risk factors, and not induction of labor per se, that increased cesarean delivery. CONCLUSION: Risk factors intrinsic to the patient, rather than labor induction itself, are the cause of excess cesarean deliveries in women with prolonged pregnancies.     

Is vaginal birth after cesarean less expensive than repeat cesarean delivery?

OBJECTIVE: This study was undertaken to compare total medical costs of trial of labor after cesarean with those of elective repeat cesarean without labor, with both short- and long-term neonatal costs associated with such procedures taken into account. STUDY DESIGN: Costs associated with All Patient Refined diagnosis-related groups and Current Procedural Terminology for a large not-for-profit health care system were applied to an algorithm describing maternal and neonatal outcomes of trial of labor. Perinatal morbidity rates and cost estimates for long-term neurologic damage associated with uterine rupture were derived from published literature. RESULTS: If a 70% vaginal birth rate for women undergoing a trial of labor and delivery in a tertiary center with a mean uterine rupture to delivery time of 13 minutes is assumed, the net cost differential ranged from a saving of $149 to a loss of $217, depending on morbidity assumptions. For vaginal birth after cesarean success rates <70%, trial of labor in the presence of two previous scars, and institutional factors increasing the perinatal morbidity rate by just 4% with respect to that seen in tertiary centers, trial of labor resulted in a net financial loss to the health care system regardless of all other assumptions made. CONCLUSIONS: When costs as opposed to charges are considered and the cost of long-term care for neurologically injured infants is taken into account, trial of labor after previous cesarean is unlikely to be associated with a significant cost saving for the health care system. Recent government-mandated length-of-stay requirements are likely to make the economic benefit of vaginal birth after cesarean even less favorable. Factors other than cost must govern decisions regarding trial of labor or repeat cesarean.     

Comparison of labor progression between induced and noninduced multiparous women

OBJECTIVE: The incidence of labor induction is rising rapidly in the United States. Among multiparas, labor is often followed with traditional labor curves derived from noninduced pregnancies. We sought to determine how labor progression of multiparous women who presented in spontaneous labor differed from those who were electively induced with and from those induced without preinduction cervical ripening. METHODS: We analyzed data on all low-risk multiparous women with an elective induction or spontaneous onset of labor between 37(+0) and 40(+6) weeks of gestation from January 2002 to March 2004 at a single institution. The median duration of labor by each centimeter of cervical dilatation and the risk of cesarean delivery were computed for 61 women with preinduction cervical ripening and oxytocin induction, 735 women with oxytocin induction, and 1,885 women with a spontaneous onset of labor. An intracervical Foley catheter was used to ripen the cervix. RESULTS: Those women who experienced electively induced labor without cervical ripening had a shorter active phase of labor than did those admitted in spontaneous labor (99 minutes in induced labor versus 161 minutes in spontaneous labor, P < .001). However, the cesarean delivery rate was elevated in the induction group (3.9% versus 2.3%, P < .05). Women who underwent preinduction cervical ripening also had a shorter active phase than those admitted in spontaneous labor (109 minutes versus 161 minutes, P = .01). CONCLUSION: The pattern of labor progression differs for women with an electively induced labor without cervical ripening compared with those who present with spontaneous onset of labor.     

Isolated oligohydramnios in term pregnancy as an indication for induction of labor.

OBJECTIVE: To evaluate the outcome of active induction of labor for isolated oligohydramnios in low-risk term gestation. METHODS: This retrospective study analyzed the obstetric and perinatal outcome of 412 singleton term pregnancies with cephalic presentation and no maternal risk factors or fetal abnormalities. Two groups were compared: 206 deliveries after induced labor for isolated oligohydramnios, and 206 deliveries matched for gestational age following spontaneous labor with normal amniotic fluid index. RESULTS: The overall rate of cesarean deliveries and cesarean deliveries for nonreassuring fetal status, and operative vaginal delivery rates and those for nonreassuring fetal status were higher in the oligohydramnios group than in the control group. There were no differences between groups in neonatal outcome or perinatal morbidity or mortality. CONCLUSION: Active induction of labor in term low risk gestations with isolated oligohydramnios translated into higher labor induction, operative vaginal delivery and cesarean section rates. This led to increased maternal risk and an increase in costs with no differences in neonatal outcome.     

Risk of cesarean delivery in nulliparous women at greater than 41 weeks' gestational age with an unengaged vertex

OBJECTIVE: The purpose of this study was to determine whether an unengaged vertex significantly increased the risk of cesarean delivery in nulliparous patients at 41 weeks or greater. STUDY DESIGN: The medical records from all nulliparous patients greater than 41 weeks' gestation delivered at a single institution were reviewed. Patients undergoing both spontaneous and induced labor were included. Multivariate analyses were used to compare the influence of admission fetal station versus induction of labor on the risk of cesarean delivery. RESULTS: Four hundred forty-eight nulliparous women at greater than 41 weeks' gestation were delivered at our institution during the study period. Sixty-two percent of these patients underwent induction of labor. There was a statistically significant increase in cesarean delivery rate compared with station (6% of patients at -1 station, 20% at -2 station, 43% at -3 station, and 77% at -4 station; P=.001). Compared with patients with an engaged vertex, patients with an unengaged vertex had 12.4 times the risk of cesarean delivery. Most of the cesarean deliveries were performed for failure to progress. On the basis of multivariate analysis, the odds of cesarean delivery were better predicted by fetal station than induction of labor. CONCLUSION: Nulliparous patients at 41 weeks or greater with an unengaged vertex are 12.4 times more likely to be delivered by cesarean section than a patient with an engaged vertex.     

Increased risk of cesarean delivery with advancing maternal age: indications and associated factors in nulliparous women

OBJECTIVE: To investigate factors that contribute to the increased risk of cesarean delivery with advancing maternal age. STUDY DESIGN: We reviewed demographic and ante- and intrapartum variables from a data set of term, nulliparous women who delivered at Brigham and Women's Hospital in 1998 (n = 3715). RESULTS: Cesarean delivery rates increased with advancing maternal age (< 25 years, 11.6%; > or = 40 years, 43.1%). Older women were more likely to have cesarean delivery without labor (< 25 years, 3.6%; > or = 40 years, 21.1%). Malpresentation and prior myomectomy were the indications for cesarean delivery without labor that were more prevalent in our older population as compared to our younger population. Even among women with spontaneous or induced labor, cesarean delivery rates increased with maternal age (< 25 years, 8.3%; > or = 40 years, 30.6%). Cesarean delivery rates were higher with induced labor, and rates of induction rose directly and continuously with maternal age, especially the rate of elective induction. Cesarean delivery for failure to progress or fetal distress was more common among older parturients, regardless of whether labor was spontaneous or induced. Among women who underwent cesarean delivery because of failure to progress, use of oxytocin and length of labor did not vary with age. CONCLUSIONS: Older women are at higher risk for cesarean delivery in part because they are more likely to have cesarean delivery without labor. However, even among those women who labor, older women are more likely to undergo cesarean delivery, regardless of whether labor is spontaneous or induced. Part of the higher rate among older women who labor is explained by a higher rate of induction, particularly elective induction. Among women in both spontaneous and induced labor, cesarean delivery for the diagnoses of failure to progress and fetal distress was more frequent in older patients, although management of labor dystocia for these patients was similar to that for younger patients.     

Trial of labor in patients with a previous cesarean section: does maternal age influence the outcome?

OBJECTIVE: This study was undertaken to evaluate the effect of maternal age on the rate of vaginal delivery and the rate of uterine rupture in patients undergoing a trial of labor (TOL) after a prior cesarean delivery. STUDY DESIGN: A cohort study of all women with a live singleton fetus undergoing a TOL after a previous low-transverse cesarean delivery was performed between 1988 and 2002 in a tertiary care center. Patients were divided into 3 groups according to maternal age: less than 30 years old, 30 to 34 years old, and 35 years or older. Women with no prior vaginal delivery and with at least 1 prior vaginal delivery were analyzed separately. The rate of vaginal delivery and the rate of symptomatic uterine rupture were calculated. Multivariate logistic regression analyses were performed to adjust for potential confounding variables. RESULTS: Of the 2493 patients who met the study criteria, there were 1750 women without a prior vaginal delivery (659, 721, and 370, respectively) and 743 women with a prior vaginal delivery (199, 327, and 217, respectively). The rate of uterine rupture was comparable between the groups (2.0%, 1.1%, 1.4%, P=.404 and 0%, 0.3%, 0.9%, P=.312). Successful vaginal delivery was inversely related to maternal age (71.9%, 70.7%, 65.1%, P=.063, and 91.5%, 91.1%, 82.9%, P=.005). After adjusting for confounding variables, maternal age equal to or greater than 35 years old was associated with a lower rate of successful vaginal delivery in patients without prior vaginal delivery (odds ratio [OR] 0.73, 95% CI: 0.56-0.94), and in patients with a prior vaginal delivery (OR: 0.47, 95% CI: 0.29-0.74). CONCLUSION: Patients who are 35 years or older are more prone to have a failed TOL after a prior cesarean delivery.     

Effect of prior vaginal delivery or prior vaginal birth after cesarean delivery on obstetric outcomes in women undergoing trial of labor

OBJECTIVE: We sought to study the effects of prior vaginal delivery or prior vaginal birth after cesarean delivery (VBAC) on the success of a trial of labor after a cesarean delivery. METHODS: An observational study of patients who underwent a trial of labor after a single low-transverse cesarean delivery. Patients with a previous cesarean delivery and no vaginal birth were compared with patients with a single vaginal delivery before or after the previous cesarean delivery. The rates of successful VBAC, uterine rupture, and scar dehiscence were analyzed. Multivariable regression was performed to adjust for confounding variables. RESULTS: Of 2,204 patients, 1,685 (76.4%) had a previous cesarean delivery and no vaginal delivery, 198 (9.0%) had a vaginal delivery before the cesarean delivery, and 321 (14.6%) had a prior VBAC. The rate of successful trial of labor was 70.1%, 81.8%, and 93.1%, respectively (P <.001). A prior VBAC was associated with fewer third- and fourth-degree lacerations (8.5% versus 2.5% versus 3.7%, P <.001) and fewer operative vaginal deliveries (14.7% versus 5.6% versus 1.9%, P <.001) but not with uterine rupture (1.5% versus 0.5% versus 0.3%, P =.12). Patients with a prior VBAC had, in addition, a higher rate of uterine scar dehiscence (21.8%) compared with patients with a previous cesarean delivery and no vaginal delivery (5.3%; P =.001). CONCLUSION: A prior vaginal delivery and, particularly, a prior VBAC are associated with a higher rate of successful trial of labor compared with patients with no prior vaginal delivery. In addition, prior VBAC is associated with an increased rate of uterine scar dehiscence.