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.     

Elective induction of labor in multiparous women. Does it increase the risk of cesarean section?

OBJECTIVE: To determine whether the medical initiation of labor places the multiparous woman at increased risk of cesarean section. STUDY DESIGN: This study was a retrospective, case-control assessment of the risk of cesarean section in multiparas with no medical or obstetric complications and vertex presentations whose induction of labor at term was judged to be elective by chart analysis. Case women were matched for age, parity, gestational age and staff obstetrician with controls in spontaneous labor, and the rates of cesarean delivery were compared. RESULTS: Three hundred four case-control pairs were studied. No significant difference was observed in the rate of cesarean delivery between the two groups. The rate of cesarean section in the electively induced group was 3.6% versus 4.3% in the control group (P = .6670). Neither cervical state nor use of cervical ripening agents significantly affected the rate of cesarean delivery. CONCLUSION: As compared with spontaneous labor, the elective induction of labor in multiparous women without complications does not predispose to cesarean delivery.     

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.     

Two different regimens of preinduction ripening of the uterine cervix with prostaglandin E2: a randomized clinical study

A randomized clinical study was designed to test the relative efficacy of preinduction cervical ripening with 0.25 mg prostaglandin E₂ (PGE₂), repeated if necessary (group 1) compared to a single maturation with 0.50 mg PGE₂ (group 2). In group 1 (n = 42), the ripening process was repeated every day until spontaneous onset of labor occurred or induction with oxytocin was decided (for improved Bishop score above 5, or maternal or fetal distress). In group 2 (n = 42) the patients who had not labored 12 h after the maturation procedure had labor induced with oxytocin, irrespective of their cervical status. In group 1, 28 patients experienced repeated maturations (from 2 to 9). Thirty patients had an induction of labor with oxytocin in group 2 and only 12 in group 1 (P < 0.0001). There were four failures of induction of labor in group 2 and none in group 1 (P < 0.05). Three episodes of myometrial hyperstimulation requiring an emergency cesarean section for acute fetal distress occurred in group 2 and none in group 1. There were 13 cesarean sections in group 2 and eight in group 1. The outcome of pregnancy was otherwise similar in both groups. In order to avoid failure of induction of labor, pre-induction cervical ripening with 0.25 mg PGE₂, repeated daily if necessary, is therefore recommended in high risk pregnancy unless a severe maternal or a fetal distress call for a prompt delivery irrespective of the cervical status.     

Intervention rates after elective induction of labor compared to labor with a spontaneous onset. A matched cohort study

INTRODUCTION: Elective induction of labor has become a widely used procedure in obstetrics. A number of studies have shown an increased incidence of operative deliveries. The objective of this study was to evaluate the rate of interventions in our hospital, including operative delivery. METHODS: A matched cohort study in which labor of 122 electively induced women and 122 women with labor with a spontaneous onset were analyzed retrospectively. These women were matched for parity and gestational age. RESULTS: Pain relief, fetal scalp blood sampling and operative deliveries were recorded more frequently in the electively induced labor group. Cesarean delivery was found in 15% of women with induced labor, and in 1% of labors with a spontaneous onset (relative risk 18 (95% CI 2.4-132.7)). No differences were found in neonatal outcomes. CONCLUSIONS: Elective induction of labor leads to increased intervention rates during labor. The rate of cesarean delivery is high, particular in nulliparous women and multiparous women without a previous vaginal birth.     

Parturition-induced changes in maternal plasma cortisol levels.

Total maternal plasma cortisol levels were measured by a radioassay method in 9 patients who were in spontaneous labor and 10 patients who were electively induced at term with oxytocin. Determinations were made at onset of labor and repeated at full cervical dilatation. Total maternal plasma cortisol levels were also measured in 7 patients undergoing elective cesarean section without labor, determinations being made just prior to the procedure and at the time of uterine incision. Computerized analysis showed the mean initial cortisol level (+/- SE) in the spontaneous labor group (15.4 +/- 1.6 mug/100 ml) to be significantly less than the mean initial level of the group electively delivered by oxytocin induction (37.2 +/- 6 mug/100 ml), with P less than 0.01. The former value was also found to be significantly less than that of the group electively delivered by cesarean section (32.1 +/- 9.3 mug/100 ml), with P less than 0.05. A significant rise was noted at full cervical dilatation in the spontaneous labor group (P less than 0.05), whereas no change occurred in the two elective groups. No significant correlation was found between the maternal cortisol levels on the one hand and the cord cortisol levels. These findings indicate that a) maternal participation is unlikely in bringing about a surge of fetal plasma cortisol which is thought to precede spontaneous labor, b) elective termination of term pregnancy by oxytocin induction or cesarean section may be initially more stress-provoking to the mother than spontaneous labor, and c) maternal stress as measured by plasma cortisol level is not reflected in the fetus.     

Extra-amniotic Foley catheter and prostaglandin E(2) gel for cervical ripening at term gestation.

OBJECTIVE: This study evaluated the efficacy of intravaginal prostaglandin E(2) gel in comparison with that of a Foley catheter for cervical ripening and induction of labor. STUDY DESIGN: Consecutive patients with unfavorable cervix requiring preinduction cervical ripening and induction of labor at term gestation were asked to participate in the study. One hundred and two patients were assigned to treatment with intravaginal prostaglandin E(2) gel (group 1) and 122 patients underwent the placement of an intracervical Foley catheter (group 2). After a maximum of three applications of intravaginal prostaglandin E(2) gel (18h) or after 18h from Foley catheter insertion oxytocin was administered to patients not in active labor. Labor profiles and pregnancy and neonatal outcome were compared between groups. RESULTS: The groups were comparable in term of demographic characteristics, indications for induction of labor, Bishop score at admission. The induction to labor time and the induction to delivery time were similar between groups. The cesarean sections rate was higher in group 1 than in group 2 (26.5 versus 14.7%, P<0.05). This remained significant when the analysis was restricted to nulliparous patients (32.3 versus 14.2%). The incidence of urinary tract infections, chorioamnionitis, and febrile morbidity was similar between groups. CONCLUSION: For preinduction cervical ripening, the Foley catheter is a valid alternative to the application of intravaginal prostaglandin E(2) gel and it is associated with a lower cesarean rate in nulliparous women.     

Effect of epidermal growth factor on hormone secretion by term placenta in organ culture

Labor, delivery, and newborn course were studied in 621 pregnancies in which labor was electively induced at or after 39 weeks, and in 3,851 control pregnancies in which the onset of labor was spontaneous. Induced labors were not prolonged, nor was the duration of ruptured membranes. Fetal distress and birth asphyxia were not more frequent after induction, and release of meconium occurred much less frequently (9.3% for induced labor versus 16.7% for spontaneous). There was greater use of epidural analgesia and of forceps delivery in induced labor. Among primiparous patients, cesarean delivery for “failure to progress” was performed in 14% of electively induced labors and 7% of spontaneous control labors, a difference not noted among multiparous patients who had a primary cesarean birth rate of less than 2%, latrogenic prematurity was not a problem; none of the 621 infants who was born after elective induction developed respiratory distress syndrome, and only one weighed less than 2,500 gm.     

Management of spontaneous rupture of the membranes in the absence of labor in primigravid women at term

One hundred and thirty-five healthy primigravid women at or near term with spontaneous rupture of the membranes without uterine contractions were submitted to a prospective trial of management. Rupture of the membranes was diagnosed by speculum examination. If labor did not commence, induction was performed by oxytocin infusion starting at 9 AM following admission. One hundred and five women went into labor spontaneously before induction became necessary. Sixty-three of these women required augmentation with oxytocin. Twenty-seven percent of the induced group required cesarean section delivery compared to 10% of those in spontaneous labor augmented by oxytocin and to none of those who did not require oxytocin (p less than 0.01). Ninety-four percent of those in spontaneous labor were delivered vaginally compared to 73% of the induced group (p less than 0.01). Forty-one percent of the augmented group were delivered by forceps. Awaiting the spontaneous onset of labor for 24 hours or less did not result in clinical maternal or neonatal infection. We would therefore advocate awaiting the spontaneous onset of labor after spontaneous rupture of membranes without contractions at or near term in healthy primigravid women for up to 24 hours because it seems to confer significant advantages without producing any additional hazard.     

Maternal and neonatal outcomes after induction of labor without an identified indication

OBJECTIVE: This study was undertaken to examine associations between induction of labor and maternal and neonatal outcomes among women without an identified indication for induction. STUDY DESIGN: This was a population-based cohort study of 2886 women with induced labor and 9648 women with spontaneous labor who were delivered at 37 to 41 weeks' gestation, all without identified medical and obstetric indications for induction. RESULTS: Among nulliparous women 19% of women with induced labor versus 10% of those with spontaneous labor underwent cesarean delivery (adjusted relative risk, 1.77; 95% confidence interval, 1.50-2.08). No association was seen in multiparous women (relative risk, 1.07; 95% confidence interval, 0. 81-1.39). Among all women induction was associated with modest increases in instrumental delivery (19% vs 15%; relative risk, 1.20; 95% confidence interval, 1.09-1.32) and shoulder dystocia (3.0% vs 1. 7%; relative risk, 1.32; 95% confidence interval, 1.02-1.69). CONCLUSION: Among women who lacked an identified indication for induction of labor, induction was associated with increased likelihood of cesarean delivery for nulliparous but not multiparous women and with modest increases in the risk of instrumental delivery and shoulder dystocia for all women.     

Uterine rupture and dehiscence associated with intravaginal misoprostol cervical ripening

OBJECTIVE: To evaluate if the prostaglandin E1 analogue misoprostol, when used as an agent for cervical ripening, is associated with uterine rupture. STUDY DESIGN: We performed a two-year retrospective chart review to determine the incidence of uterine rupture in patients with a previous cesarean delivery undergoing cervical ripening or the induction of labor. RESULTS: Uterine dehiscence occurred in 1 and uterine rupture occurred in 3 of 48 women with a prior cesarean delivery treated with 50 micrograms doses of intravaginal misoprostol for cervical ripening. Uterine rupture was found in 1 of 89 women who had an oxytocin infusion for induction of labor and none of the 24 patients who received intravaginal prostaglandin E2 placed for cervical ripening. CONCLUSION: Intravaginal misoprostol appears to be associated with an increased incidence of uterine rupture when used in patients undergoing a trial of labor after cesarean.     

Extra-amniotic saline infusion increases cesarean risk versus other induction methods and spontaneous labor

Extra-amniotic saline infusion (EASI) via a Foley catheter has been thought to be comparable in efficacy to other induction and cervical ripening methods. This study examines the risk of cesarean delivery associated with EASI compared with spontaneous labor and other methods of cervical ripening. A retrospective cohort study based upon deliveries at Bellevue Hospital Center from August 2000 to December 2002 was conducted. Three groups were identified: EASI, other methods of induction such as prostaglandins and oxytocin administration, and spontaneous labor. Pairwise comparisons were performed using analysis of variance and multivariate logistic regression analysis to control for confounding variables. There were 625 charts evaluated: including 171 with EASI, 190 with other induction methods, and 264 with spontaneous labor. The rates of cesarean section were 33.9%, 17.9%, and 7.2%, respectively. When compared with spontaneous labor, there was a higher risk of cesarean delivery for subjects induced with other methods (adjusted odds ratio [OR], 2.4; 95% confidence interval [CI], 1.3 to 4.5; P < 0.001), and for those induced with EASI (adjusted OR, 5.5; 95% CI, 3.1 to 9.9; P < 0.001). When EASI was compared with other methods of induction, the risk of cesarean delivery was still increased (adjusted OR, 2.3; 95% CI, 1.4 to 3.8; P = 0.001). EASI is associated with an increased risk of cesarean delivery compared with spontaneous labor and other methods of cervical ripening.     

Preinduction cervical ripening with the Foley catheter and the risk of subsequent preterm birth

OBJECTIVE: The Foley catheter is a safe and effective form of preinduction cervical ripening and is quickly growing in popularity. Its major effect appears to be through mechanical dilation, which has raised the concern that the use of the Foley catheter for cervical ripening may damage the cervix and result in a higher rate of subsequent preterm birth. STUDY DESIGN: We conducted a review of all induction of labor at our institution from July 1998 to July 2001 that required preinduction cervical ripening and had a subsequent birth. The primary outcome variable was preterm birth at <35 weeks of gestation. Demographic and potential confounding variables were analyzed. A probability value of <.05 was considered significant. RESULTS: The cases of 126 women (63 women in the Foley group and 63 women in the prostaglandin group) were studied. Women in the prostaglandin group had a prostaglandin agent used. There was no difference in maternal age, gravidity, parity, Bishop score, total time of induction, gestational age, oxytocin use, maximum oxytocin level, tobacco or drug use, or type of delivery in the index pregnancy between the groups. In the subsequent pregnancies, there were no differences in maternal age, gravidity, parity, spontaneous abortions, terminations, cone or Loop Electrosurgical Excision Procedure (LEEP) procedures, history of cervical manipulation, tobacco or drug use, stillbirth, need for induction, mode of delivery, episiotomy, gestational age at delivery, Apgar scores, labor duration, use of oxytocin, or birth weight. There were no differences in preterm birth at 37, 35, or 32 weeks of gestation between the groups. CONCLUSION: The use of the Foley catheter for preinduction cervical ripening does not appear to increase the risk of preterm birth in a subsequent pregnancy.     

Management of term patients with premature rupture of membranes and an unfavorable cervix.

The purpose of this prospective investigation was to evaluate a protocol for management of term patients with premature rupture of membranes (PROM) and a cervix unfavorable for induction of labor (Bishop score 4 or less). Patients initially were observed for 24 to 36 hours for the spontaneous onset of labor. If spontaneous contractions did not commence, labor was induced with oxytocin. Patients subsequently were divided into three groups: 44 who had spontaneous labor, 29 who had spontaneous labor but required oxytocin augmentation, and 39 women who had oxytocin induction. Patients who entered labor spontaneously had a significantly shorter mean latent period between rupture of membranes and onset of labor (16.0 versus 26.8 and 40.7 hours), shorter mean duration of labor (7.6 versus 12.1 and 13.1 hours), and shorter mean duration of rupture of membranes (23.6 versus 39.0 and 53.8 hours). These women also had a significant decrease in the frequency of chorioamnionitis (7 versus 14 and 33%), and their infants had fewer evaluations for sepsis (25.0 versus 34.5 and 53.8%). We conclude that term patients with PROM and an unfavorable cervix who require oxytocin augmentation or induction of labor are at increased risk for intrapartum and neonatal infection compared with those who progress through labor spontaneously.     

Induction of labor in postterm pregnant women

We have studied the outcome of labor induction in 145 postterm pregnant women in whom gestational age was properly assessed by ultrasound scanning. The induction techniques were adapted to the cervical states of the patients. Seventy-five patients (32 nulliparous and 43 multiparous) with favorable cervical states were successfully induced with intravenous oxytocin. In this group the frequency of Caesarean section was 2%. Seventy patients (45 nulliparous and 25 multiparous) with unripe cervices received 0.5 mg PGE2 in viscous gel intracervically to prime the cervix and to induce labor; 38 (52%) were induced into labor after a single PGE2-gel application whereas 26 (48%) needed labor augmentation with intravenous oxytocin after PGE2-gel obtained cervical ripening. In 6 of the 20 patients the cervix did not ripen and the PGE2-gel application had then to be repeated. The frequency of cesarean sections was 11%. In 5 out of the 145 patients (4%) the fetuses had signs of intrauterine growth retardation (IUGR) as assessed by ultrasound scanning, and postmaturity as verified by pediatric examination at delivery. All these fetuses belonged to nulliparous women with unripe cervices and all had to be delivered instrumentally (3 by cesarean section and 2 by ventouse) indicating the fragility of these children. If postterm pregnancy is complicated by an unfavorable cervical state intracervical application of PGE2-gel seems to be an efficient method to prime the cervix and to induce labor. In most patients an uncomplicated vaginal delivery can be achieved by this procedure. However, nulliparous women with unfavorable cervices and signs of IUGR constitute a high risk group of patients at labor induction.     

A randomized trial of prostaglandin E2 in a controlled-release vaginal pessary for cervical ripening at term.

OBJECTIVE: The purpose of this study was to determine if prostaglandin E2 in a controlled-release vaginal pessary can produce cervical ripening at term. STUDY DESIGN: This was a double-blind, randomized, placebo-controlled study conducted at a university center and involving 81 patients with 42 receiving active agent. Categoric data were analyzed by Pearson's chi 2 or logistic regression. Continuous variables were analyzed by analysis of variance and the F test. RESULTS: Prostaglandin E2 was significantly better than placebo at cervical ripening and at decreasing the time to rupture of membranes, the time to onset of labor, the need to give oxytocin, and the time to vaginal delivery. Multiparous women benefitted more than primiparous ones. The cesarean section rate decreased only for multiparous women. Uterine hyperstimulation occurred only with prostaglandin E2 and after the onset of labor. CONCLUSIONS: Prostaglandin E2, when administered in a controlled-release vaginal pessary, is affective in producing cervical ripening at term. This agent should be used on inpatients who are under continuous monitoring and it should be removed at the onset of labor.     

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.     

A prospective randomized trial of labor induction with vaginal controlled-release dinoprostone inserts with or without oxytocin and misoprostol+oxytocin

OBJECTIVE: This study was designed in an aim to compare the efficacies of three labor induction methods, dinoprostone (PGE2) vaginal insert with or without concomittant oxytocin and misoprostol (PGE1) combined with oxytocin infusion. METHODS: This was a prospective observational trial of nulliparous women undergoing labor induction from December 2006 to January 2007. Inclusion criteria were: gestational age between 36 to 42 weeks, singleton cephalic presentation of the fetus, intact membrane and unfavorable cervical Bishop score < 6, and absence of spontaneous uterine contractions. Participants were then randomly assigned to preinduction cervical ripening with a dinoprostone vaginal insert (10 mg) administered into the posterior fornix for a total of 12 hours without oxytocin (group I); with oxytocin (group II), and with misoprostol (50 microg) intravaginally in the posterior fornix with repeat dosing at 6-hour intervals with a maximum dose of four with oxytocin (group III). RESULTS: A total number of 106 women met the inclusion criteria without distribution for 19 cases in group I, 44 and 43 cases in groups II and III, respectively. There were no statistically significant differences in terms of the demographic characteristics, indication of labor induction, interval from-induction-to-delivery, cardiotocographic abnormalities and neonatal outcomes and mode of deliveries among the three groups (p > 0.05). CONCLUSIONS: Three methods of labor induction were equally efficient in achieving succesful delivery without any maternal and fetal adverse outcomes.     

Extra-amniotic saline, laminaria, or prostaglandin E(2) gel for labor induction with unfavorable cervix: a randomized controlled trial

OBJECTIVE: To determine which of three methods of cervical ripening resulted in the lowest cesarean rate in women with unfavorable cervices and indications for labor induction. METHODS: Consenting women with singleton gestations, vertex presentations, and unfavorable cervices (dilatation under 2 cm and effacement under 75%) were randomly assigned to laminaria and standard intravenous oxytocin, serial doses of intracervical prostaglandin (PG) E(2) gel (Prepidil, Pharmacia & Upjohn, Inc., Kalamazoo, MI) 0.5 microg every 6 hours for two doses followed by oxytocin if indicated, or extra-amniotic saline infusion and oxytocin. RESULTS: An interim analysis after recruitment of 321 subjects, 67% of the planned sample, found similar cesarean rates for the three groups (laminaria 36%; PGE(2) gel 33%; saline infusion 29%; P =.59); however, the mean randomization-to-delivery interval was significantly longer in the PGE(2) group. Stochastic curtailment, as part of the interim analysis, indicated a low likelihood of achieving a statistically significant difference in cesarean rates between PGE(2) gel and the other two groups. Therefore, we completed the study with saline infusion and laminaria. The saline infusion and laminaria groups had similar preinduction characteristics. The cesarean rates were similar (saline infusion 25.4% versus laminaria 30.3%; P =.32), but the mean interval from randomization to delivery was shorter in the saline infusion group (18.0 versus 21.5 hours, P =.002). There were no significant differences in selected maternal and neonatal morbidities. CONCLUSION: Cervical ripening with extra-amniotic saline infusion, PGE(2), or laminaria resulted in comparable cesarean rates in women with an unfavorable cervix and indications for labor induction. Extra-amniotic saline infusion had the shortest randomization-to-delivery interval without increasing maternal or neonatal morbidity.     

Uterine rupture associated with misoprostol labor induction in women with previous cesarean delivery

OBJECTIVE: To review our experience with uterine rupture in patients undergoing a trial of labor with a history of previous cesarean delivery in which labor was induced with misoprostol. STUDY DESIGN: A retrospective chart review was used to select patients who underwent induction of labor with misoprostol during the period from February 1999 to June 2002. Women with a history of cesarean delivery were retrospectively compared with those without uterine scarring. RESULTS: Uterine rupture occurred in 4 of 41 patients with previous cesarean delivery who had labor induced with misoprostol. The rate of uterine rupture (9.7%) was significantly higher in patients with a previous cesarean delivery (P<0.001). No uterine rupture occurred in 50 patients without uterine scarring. Women with a history of cesarean delivery were more likely to have oxytocin augmentation than those without uterine scarring (41% versus 20%; P=0.037). CONCLUSION: Misoprostol induction of labor increases the risk of uterine rupture in women with a history of cesarean delivery.