Is membrane sweeping beneficial at the initiation of labor induction?

Objective: To determine whether cervical membrane sweeping during labor induction is beneficial.

Methods: Outcomes of labor after induction in pregnant women at term were compared in a randomized trial. Women were assigned to having their membranes “swept” or “not swept” at the initiation of labor induction.

Results: We recruited a total of 870 women of which 70 were excluded. There were 400 nullipara (Group A) [198 “swept”, 202 “not swept”] and 400 multiparas (Group B) (201 “swept” and 199 “not swept”]. Among group A who received intravaginal prostaglandin (PG) E₂, those who had simultaneous sweeping had significantly shorter mean induction-labor interval (12.9?±?1.3 versus 16.2?±?1.1 hours, p?=?0.046), lower mean dose of oxytocin (6.6?±?0.6 versus 10.11?±?1.4?mU/minute, p?=?0.01), and increased normal delivery rates (vaginal delivery 82.8% versus 58.6%, p?=?0.01). Sweeping also had a favorable effect on nulliparas who had ARM and received oxytocin alone (mean induction-labor interval 5.9?±?2.9 versus 10.9?±?2.6 hours p?=?0.04, mean maximum dose of oxytocin 9.8?±?1.1 versus 15.2?±?1.1?mU/min, p?=?0.01). These results were restricted to women with unfavorable cervix in Group A those who had membrane sweeping.

Conclusion: Membrane sweeping, has beneficial effects on labor and delivery, which is limited to nulliparas with unfavorable cervix requiring PGE₂ or Oxytocin alone.     

Membrane sweeping at initiation of formal labor induction: a randomized controlled trial

OBJECTIVE: To determine the benefit of membrane sweeping at initiation of labor induction in conjunction with formal methods of labor induction. METHODS: Two hundred seventy-four women at term with a singleton fetus in cephalic presentation and intact membranes were randomly assigned to receive membrane sweeping or no membrane sweeping at initiation of formal labor induction with either dinoprostone pessary or amniotomy. Outcome measures included mode of delivery, induction-to-delivery interval, dinosprostone dose, any oxytocin use and duration of oxytocin use in labor, visual analog score for pain associated with sweeping, and visual analog score for satisfaction with the birth process. RESULTS: Two hundred sixty-four women (136 sweep and 128 no sweep) had their data analyzed. Ten women (4 sweep and 6 no sweep) were excluded because of exclusion criteria infringements. Swept women had higher spontaneous vaginal delivery rate (69% compared with 56%, P = .041), shorter induction to delivery interval (mean 14 compared with 19 hours, P = .003), fewer that required oxytocin use (46% compared with 59%, P = .037), shorter duration of oxytocin infusion (mean 2.6 compared with 4.3 hours, P = .001) and improved visual analog score for birth process satisfaction (mean 4.0 compared with 4.7, P = .015). The reduction in dinoprostone dose used (mean 1.2 compared with 1.3, P = .082) was not significant. Postsweeping visual analog score for pain (mean 4.7 compared with 3.5, P < .001) was significantly increased. CONCLUSION: Membrane sweeping at initiation of labor induction increased the spontaneous vaginal delivery rate, reduced oxytocic drug use, shortened induction to delivery interval, and improved patient satisfaction. LEVEL OF EVIDENCE: I.     

Mifepristone for preinduction cervical ripening beyond 41 weeks' gestation: a randomized controlled trial

OBJECTIVE: To compare the effect of mifepristone with placebo on cervical ripening before labor induction in prolonged pregnancies. METHODS: One hundred eighty women with pregnancies beyond 41 weeks and undilated, uneffaced cervices were assigned randomly to receive mifepristone 200 mg or placebo and observed for 24 hours. We then gave intravaginal misoprostol 25 microg every 4 hours or intravenous oxytocin. We expected 60% of placebo-treated and 80% of mifepristone-treated women to deliver vaginally within 48 hours. RESULTS: Among 180 subjects, 97 received mifepristone and 83 received placebo. The mean interval (+/- standard deviation [SD]) from start of induction to delivery was 2209 +/- 698 minutes for mifepristone-treated subjects and 2671 +/- 884 minutes for placebo-treated subjects (P <.001, log-transformed data). Twelve (13. 6%) mifepristone-treated women and seven (10.8%) placebo-treated women delivered vaginally on day 1 (P =.60). After 24 hours, the median Bishop score for both groups was 3 (0-11) (P =.51). One hundred thirty-one subjects required misoprostol, 65 (67.0%) were mifepristone-treated women, and 66 (79.5%) placebo-treated women (P =.06). The median (range) oxytocin dose was 871.5 (0-22,174) mU for mifepristone-treated women and 2021.0 (0-24,750) mU for placebo-treated women (P =.02). Seventy-seven (87.5%) mifepristone-treated women and 46 (70.8%) placebo-treated women delivered vaginally 48 hours after the start of treatment (P =.01). There were nine cesareans in the mifepristone group and 18 in the placebo group (P =.02). More nonreassuring fetal heart rate patterns and uterine contractile abnormalities occurred in mifepristone-treated subjects. There were no statistically significant differences in neonatal outcomes between groups. CONCLUSION: Mifepristone had a modest effect on cervical ripening when given 24 hours before labor induction, appearing to reduce the need for misoprostol and oxytocin compared with placebo.     

The association of maternal weight with cesarean risk, labor duration, and cervical dilation rate during labor induction

OBJECTIVE: To assess the relationship among maternal weight and cesarean delivery, cervical dilation rate, and labor duration. METHODS: We used a secondary analysis of 509 term women who were previously enrolled in a prospective observational study of a labor induction protocol in which standardized criteria were used for labor management. A variety of analyses were performed, both unadjusted and adjusted. P <.05 was considered significant. RESULTS: The mean +/- standard deviation weight of women who underwent a cesarean (97 +/- 29 kg) was significantly higher than that of women who were delivered vaginally (87 +/- 22 kg, P <.001). In a logistic regression model of nulliparas who comprised 71% of the study population, after adjustment for the confounding effects of infant birth weight, maternal age, initial cervical dilation, and diabetes, for each 10-kg increase in maternal weight, the odds ratio for cesarean delivery was significantly increased (odds ratio 1.17; 95% confidence interval 1.04, 1.28). In a linear regression model also limited to nulliparas and after adjusting for the same confounders, the rate of cervical dilation was inversely associated with maternal weight: for each 10-kg increment, the rate of dilation was decreased by 0.04 cm/h (P =.05). Similarly, labor duration was positively associated with maternal weight: for each 10-kg increment, an increase in the oxytocin to delivery interval of 0.3 hours was observed in nulliparas (P =.02). Neither lower rates of oxytocin administration to heavier women nor diminished uterine responsiveness (as reflected in measured Montevideo units) accounted for the slower labor progress. CONCLUSION: In nulliparous women undergoing labor induction, maternal weight was associated with a higher cesarean risk and longer labor and was inversely proportional to the cervical dilation rate. LEVEL OF EVIDENCE: II-2     

A comparison of vaginally administered misoprostol with extra-amniotic saline solution infusion for cervical ripening and labor induction

OBJECTIVE: The purpose of this study was to compare intravaginal misoprostol with extra-amniotic saline solution infusion with concomitant oxytocin for cervical ripening and labor induction in viable pregnancies. STUDY DESIGN: Two hundred women with indications for labor induction and unfavorable cervices were assigned randomly to vaginal misoprostol or extra-amniotic saline solution infusion. Twenty-five micrograms of misoprostol was administered every 4 hours up to six doses, followed by intravenous oxytocin administration. Patients who had received extra-amniotic saline solution infusion also received intravenous oxytocin along with a maximum 12-hour saline solution infusion through Foley catheters that were placed above the internal cervical os. RESULTS: One hundred women were randomly assigned to misoprostol, and 100 women were assigned randomly to extra-amniotic saline solution infusion. The average interval from start of induction to vaginal delivery was longer in the misoprostol group (1323.3 +/- 700.3 minutes) than in the extra-amniotic saline solution infusion group (970.4 +/- 502.7 minutes; P =.006, log transformed data). Abnormal fetal heart rate tracings were found in 30% of the patients who received misoprostol and in 19% of the patients who received extra-amniotic saline solution infusion (relative risk, 1.6; 95% CI, 1.0-2.4; P =.05). There was more tachysystole in the misoprostol group (8%) than in the extra-amniotic saline solution infusion group (1%; P =.02). There were no differences in the routes of deliveries or neonatal outcomes between groups. CONCLUSION: Extra-amniotic saline solution infusion with oxytocin administration appears more effective and is associated with fewer maternal complications than misoprostol for cervical ripening and labor induction.     

A comparison of orally administered misoprostol with vaginally administered misoprostol for cervical ripening and labor induction.

OBJECTIVE: Our purpose was to compare orally administered with vaginally administered misoprostol for cervical ripening and labor induction. MATERIAL AND METHODS: Two hundred twenty subjects with medical or obstetric indications for labor induction and undilated, uneffaced cervices were randomly assigned to receive orally administered or vaginally administered misoprostol. Fifty micrograms of oral misoprostol or 25 microgram of vaginal misoprostol was given every 4 hours. If cervical ripening (Bishop score of >/=8 or cervical dilatation of >/=3) or active labor did not occur, repeated doses were given to a maximum of 6 doses or 24 hours. Thereafter, oxytocin was administered intravenously by a standardized incremental infusion protocol to a maximum of 22 mU/min. RESULTS: Of the 220 subjects evaluated, 110 received orally administered misoprostol and 110 received vaginally administered misoprostol. Fewer subjects who received the oral preparation (34/110, 30.9%) were delivered vaginally within 24 hours of initiation of induction, in comparison with those who received the vaginal preparation (52/110, 47.3%) (P =.01). The average interval from start of induction to vaginal delivery was nearly 6 hours longer in the oral treatment group (mean and SD 1737.9 +/- 845.7 minutes) than in the vaginal treatment group (mean and SD 1393.2 +/- 767.9) (P =.005, log-transformed data). Orally treated patients required significantly more doses than vaginally treated patients (orally administered doses: mean and SD 3.3 +/- 1.7; vaginally administered doses: mean and SD 2.3 +/- 1.2) (P <.0001). Oxytocin administration was necessary in 83 (75.4%) of 110 orally treated subjects and in 65 (59.1%) of 110 vaginally treated subjects (P =.01, relative risk 1. 28, 95% confidence interval 1.06-1.54). Vaginal delivery occurred in 95 (86.4%) orally treated subjects and in 85 (77.3%) vaginally treated subjects (P =.08, relative risk 1.12, 95% confidence interval 0.99-1.27), with the remainder undergoing cesarean delivery. There was no difference in the incidence of uterine contractile abnormalities (tachysystole, hypertonus, or hyperstimulation), intrapartum complications, or neonatal outcomes between the 2 groups. CONCLUSIONS: Oral administration of 50-microgram doses of misoprostol appears less effective than vaginal administration of 25-microgram doses of misoprostol for cervical ripening and labor induction. Further investigation is needed to determine whether orally administered misoprostol should be used for cervical ripening and labor induction.     

A randomized trial of pulsatile vs continuous oxytocin infusion for labor induction

In a prospective randomized study, 560 pregnant women were subjected to labor induction with continuous or pulsed intravenous oxytocin infusion. There were no significant differences with respect to maternal history, Bishop score and perinatal morbidity. The mean induction to delivery interval was shorter in the pulsed infusion group than in the continuous infusion group (325 +/- 63 vs 433 +/- 67 min in primiparous, p < 0.001 and 204 +/- 52 vs 236 +/- 87 min in multiparous women, p < 0.01). The mean amount of oxytocin administered in the pulsed infusion group was also significantly lower than in the continuous infusion group (4.7 +/- 0.6 mU/min versus 9.6 +/- 3.4 mU/min in primiparous, p < 0.001 and 2.1 +/- 0.4 mU/min versus 5.2 +/- 2.3 mU/min in multiparous women, p < 0.001). Our study demonstrates that pulsatile administration of oxytocin is as safe as continuous intravenous infusion, requires less oxytocin and is more effective as it reduces labor duration.     

Randomized comparison between intravaginal misoprostol and dinoprostone for cervical ripening and induction of labor.

OBJECTIVE: We sought to evaluate the efficacy and safety of intravaginal misoprostol and dinoprostone for labor induction. STUDY DESIGN: One hundred eighty-nine women with singleton term pregnancies and unfavorable cervices were randomly assigned to receive intravaginal misoprostol or dinoprostone. The outcome variables were change in Bishop score, time from application to active phase of labor and delivery, fetal and maternal morbidity, and the incidence of cesarean deliveries. RESULTS: The interval from application of the initial dose to the beginning of the active phase of labor was 9.8 +/- 5.8 and 14.2 +/- 10.2 hours (P <.01), and the interval from initial dose to delivery was 15.3 +/- 9.8 and 19.1 +/- 13.2 hours (P =.027) for the misoprostol and dinoprostone groups, respectively. There were no significant differences in Bishop score change, cesarean delivery rate, and the incidence of tachysystole, hypersystole, and hyperstimulation. No maternal and neonatal adverse effects were noted. CONCLUSION: Intravaginal misoprostol is more effective than intravaginal dinoprostone for labor induction in low-risk patients at term with unfavorable cervices.     

Pulsatile oxytocin for induction of labor: a randomized prospective controlled study

In a prospective randomized study, 20 patients with term pregnancies underwent induction of labor with either continuous or pulsed (every 8 minutes) intravenous oxytocin infusion. There were no significant differences with respect to induction-labor interval, induction-delivery interval, cesarean section rates, need for pain relief and Apgar scores. Sixty percent of patients receiving continuous oxytocin infusion developed uterine hyperstimulation but only 10% receiving pulsed oxytocin did so. However, the difference was not significant. The mean +/- SEM total amount of oxytocin given by continuous infusion was 4237 +/- 1066 mU which was 70% more than by pulsatile infusion (2454 +/- 808 mU). The highest rate of oxytocin infused was significantly lower by pulsatile administration (5.2 +/- 0.8 mU/min) than by continuous infusion (9.2 +/- 1.8 mU/min, p = less than 0.05). Our study demonstrates that pulsed administration of oxytocin every 8 minutes is as effective and safe as continuous intravenous infusion of oxytocin for induction of labor, requires less oxytocin with therefore, a wider margin of safety and is consistent with the pulsatile release of oxytocin during normal labor.     

Oral misoprostol and intracervical dinoprostone for cervical ripening and labor induction: a randomized comparison

OBJECTIVE: To compare efficacy, safety, and tolerance of oral misoprostol with intracervical dinoprostone for cervical ripening and labor induction. METHODS: Two hundred women were randomized to receive single doses of oral misoprostol 200 microg or 0.5 mg of dinoprostone intracervically every 6 hours for a maximum four doses. RESULTS: The intervals from administration of the drug to active phase of labor (11.1 hours [7-24] versus 15.8 hours [7.5-29.62], P =. 01), to delivery (14.0 hours [8.42-27.61] versus 20.2 hours [16.7-32. 8], P =.01), and to rupture of membranes (10.0 hours [4.95-24.7] versus 15.6 hours [8.2-29.2], P =.003) were significantly shorter in the misoprostol group. All those variables were not distributed normally, so results are presented as median and interquartile range. The rates of women who needed oxytocin (68% versus 52%, P =.03) and cesarean for failed induction (9% versus 1%, P =.01) were higher in the dinoprostone group. CONCLUSION: A single dose of 200 microg oral misoprostol was more effective for cervical ripening and labor induction than 0.5 mg of dinoprostone intracervically every 6 hours, with a maximum of four doses.     

Outpatient misoprostol compared with dinoprostone gel for preinduction cervical ripening: a randomized controlled trial

OBJECTIVE: To determine whether a single outpatient dose of intravaginal misoprostol (versus intracervical dinoprostone gel) reduces the oxytocin use for induction. Despite the numerous trials examining misoprostol for induction, the efficacy of a single outpatient dose of misoprostol followed by oxytocin induction is unknown. METHODS: Patients with a term, vertex, singleton pregnancy and a Bishop score of 6 or less were randomly assigned to receive misoprostol (n = 42, 0.25 microg intravaginally) or dinoprostone gel (n = 42, 0.5 mg intracervically) the evening before oxytocin induction. Patients were monitored for 3 hours after administration and discharged to home if fetal assessment was reassuring, for readmission the next morning for oxytocin. Primary outcomes were oxytocin dose, time, and dose intensity (dose divided by duration). Secondary outcomes were incidence of labor, uterine hyperstimulation, cesarean delivery, Apgar score. Statistics used were chi(2), Student t test, Mann-Whitney rank sum test, and Fisher exact test. P < .05 was accepted as statistically significant. RESULTS: A single dose of misoprostol significantly decreased the cumulative dose of oxytocin, the cumulative time of oxytocin administration, and the dose intensity of oxytocin (dose divided by time). Data are as follows (mean +/- standard error of the mean): oxytocin dose-dinoprostone 10,929 +/- 219 mU, misoprostol 6,081 +/- 170 mU, P = .008; oxytocin time-dinoprostone 798 +/- 11 minutes, misoprostol 531 +/- 11 minutes, P = .009; dose intensity-dinoprostone 11.3 +/- 0.1 mU/min, misoprostol 7.4 +/- 0.2 mU/min, P = .003. Misoprostol induced labor during the ripening period in 19 of 41 of patients, compared with 6 of 42 after dinoprostone (P = .002). There was no difference in cesarean delivery (dinoprostone, 8/42; misoprostol, 9/42; P = 1.00). There was no difference in short-term neonatal outcome. No patient had hyperstimulation or required cesarean delivery for nonreassuring fetal assessment during the ripening period. CONCLUSION: A single dose of misoprostol administered in the outpatient setting significantly decreases oxytocin use, largely due to labor within the ripening period.     

Misoprostol outpatient cervical ripening without subsequent induction of labor: a randomized trial

OBJECTIVE: To estimate the effect of outpatient administration of a single dose of vaginal misoprostol at term on the interval to delivery in women with unfavorable cervices. METHODS: Randomized, double blind, placebo-controlled trial comparing a single 25-microg outpatient intravaginal dose of misoprostol to placebo in pregnant women with Bishop scores less than 9 at 40 weeks or greater. After placement of the study medication, subjects were permitted to go into spontaneous labor unless an indication for induction developed. Analysis was by intent to treat. The interval to delivery, defined as the time from medication placement to delivery, was compared by Student t test and by survival analysis with the log-rank test. RESULTS: Thirty-three women were randomly assigned to receive misoprostol, and 35 were assigned to receive placebo. The mean interval to delivery was significantly less in the misoprostol group, 4.2 +/- 4.1 compared with 6.1 +/- 3.6 days, P =.04. The interval to delivery for only the nulliparous patients was significantly less in the misoprostol group, 4.2 +/- 4.0 compared with 7.2 +/- 3.7 days, P =.02. The survival curves for the interval to delivery were significantly different (P =.04 by log-rank test) with 4.1 days median interval to delivery for misoprostol compared with 9.2 days for placebo. There were no adverse outcomes in either group. CONCLUSION: A single 25-microg outpatient intravaginal dose of misoprostol is effective in decreasing the interval to delivery in women with unfavorable cervices at term.     

Sweeping of the membranes versus uterine stimulation by oxytocin in nulliparous women. A randomized controlled trial

The aim of this study was to evaluate whether sweeping of the membranes at term could shorten the length of pregnancy and reduce the incidence of postterm pregnancies. We randomly selected 104 nulliparas with uncomplicated pregnancy and gestational age between 281 and 287 days. Our patients were divided into three groups. Group A consisted of 34 women who were subjected to sweeping of the membranes. Uterine stimulation with oxytocin was applied in 35 women (group B), and 35 women (group C) were used as a control group. We had no significant reduction of the time interval from sweeping of the membranes until delivery (1.9 +/- 1.2 days), compared to that of group B (2.1 +/- 0.8 days) as well as that of the control group (2.5 +/- 0.9 days). The incidence of spontaneous labor in patients after sweeping of the membranes was greater (67.6%) when compared with oxytocin-stimulated patients and the control group (p < 0.05). Furthermore, a better Bishop score was noted in patients of group A. No statistically significant difference was noted in the mode of delivery between the groups, but sweeping of the membranes significantly decreased the incidence of postterm pregnancies (p < 0. 05). We concluded that sweeping of the membranes is an effective method for initiating labor in women with a gestational age between 40 and 41 weeks, thus reducing the need for induction.     

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.     

Randomized, double-masked comparison of oxytocin dosage in induction and augmentation of labor.

OBJECTIVE: To test the hypothesis that high-dose oxytocin, when used in a masked fashion, would result in shorter labors and less need for cesarean delivery. METHODS: We conducted randomized, double-masked trials of high-dose compared with low-dose oxytocin for augmentation and induction of labor. Patients were randomly assigned to receive oxytocin by either a low-dose protocol (1.5 mU/minute initially, increased by 1.5 mU/minute every 30 minutes) or a high-dose protocol (4.5 mU/minute initially, increased by 4.5 mU/minute every 30 minutes). Oxytocin solutions were prepared by a central pharmacy and infusion volumes (mL/hour) were identical, thus ensuring double masking. RESULTS: A total of 1307 patients were randomized (induction, 816; augmentation, 491). In the group receiving oxytocin for induction, high-dose oxytocin was associated with a significant shortening of labor (oxytocin to complete dilatation: 9.7+/-0.3 compared with 7.8+/-0.2 hours, P<.001; oxytocin to delivery: 10.5+/-0.3 compared with 8.5+/-0.3 hours, P<.001). The cesarean delivery rate with low-dose oxytocin was 15.0%, compared with 11.3% with high-dose oxytocin (P = .17). For nulliparous women undergoing induction, cesarean delivery rates were as follows: Total 17.3% (low dose) compared with 11.7% (high dose), P = .15; cephalopelvic disproportion 11.9% (low dose) compared with 5.9% (high dose), P = .06. When used for augmentation, high-dose oxytocin again was associated with a significant shortening of labor without a significant difference in cesarean birth rates. No differences in neonatal outcomes were noted between the groups for either augmentation or induction. CONCLUSION: When used in a double-masked fashion, high-dose oxytocin is associated with significantly shorter labors without any demonstrable adverse fetal or neonatal effects.     

Sweeping of the membranes at 39 weeks in nulliparous women: a randomised controlled trial

Objective To determine whether weekly sweeping of the membranes from 39 weeks of gestation results in a reduction in the number of women reaching 41 completed weeks and subsequently in a reduction of the number of women who will need induction of labour.
Design Randomised controlled trial.
Participants Two hundred and seventy-eight nulliparous women, who were seen at the antenatal clinic of a university teaching hospital, were randomly allocated at 39 weeks of gestation to receive on a weekly basis either sweeping of the membranes (  n=140  ) or a routine pelvic examination (  n=138  ).
Main outcome measures The time interval between randomisation and delivery, the incidence of prolonged pregnancy (i.e. > 41 completed weeks), and the incidence of induction of labour.
Results In 24 women (17%) sweeping of the membranes was not possible. Fifty-three women (38%) in the sweeping group and 50 women (36%) in the control group were delivered within one week after randomisation. Women allocated to sweeping showed a trend towards having a shorter randomization-delivery interval: 9.4 days versus 10.6 days in the controls (   P = 0.087  ). Sweeping had no statistically significant effect on the mean duration of pregnancy (282.8 days in the sweeping group versus 283.8 days in the control group,   P = 0.127  ). The need for induction of labour was significantly reduced in those women who underwent sweeping (11% versus 26%,   P = 0.004  ), merely as a result of a decrease in the number of women that exceeded 41 weeks (19% versus 33%,   P = 0.016  ).
Conclusion Sweeping of the membranes weekly from 39 weeks does not increase the number of women who will deliver within the first week but significantly decreases the number that will reach 41 weeks. Induction of labour then becomes less necessary.     

Minimum oxytocin dose requirement after cesarean delivery for labor arrest

OBJECTIVE: To estimate the minimum effective intravenous dose of oxytocin required for adequate uterine contraction after cesarean delivery for labor arrest. METHODS: A randomized single-blinded study was undertaken in 30 parturients undergoing cesarean deliveries under epidural anesthesia for labor arrest despite intravenous oxytocin augmentation. Oxytocin was administered as a slow intravenous bolus immediately after delivery of the infant, according to a biased coin up-down sequential allocation scheme. After assisted spontaneous delivery of the placenta, the obstetrician, blinded to the oxytocin dose, assessed uterine contraction as either satisfactory or unsatisfactory. Additional boluses of oxytocin were administered as required, followed by a maintenance infusion. Data were interpreted and analyzed by a logistic regression model at 95% confidence intervals. RESULTS: All patients received oxytocin infusions at a mean +/- standard deviation of 9.8 +/- 6.3 hours before cesarean delivery (maximum infusion dose 10.3 +/- 8.2 mU/min). The minimum effective dose of oxytocin required to produce adequate uterine response in 90% of women (ED90) was estimated to be 2.99 IU (95% confidence interval 2.32-3.67). The estimated blood loss was 1,178 +/- 716 mL. CONCLUSION: Women requiring cesarean delivery for labor arrest after oxytocin augmentation require approximately 3 IU rapid intravenous infusion of oxytocin to achieve effective uterine contraction after delivery. This dose is 9 times more than previously reported after elective cesarean delivery in nonlaboring women at term, suggesting oxytocin receptor desensitization from exogenous oxytocin administration during labor. Therefore, alternative uterotonic agents, rather than additional oxytocin, may achieve superior uterine contraction and control of blood loss during cesarean delivery for labor arrest. LEVEL OF EVIDENCE: I.     

Outpatient cervical ripening with nitric oxide donor isosorbide mononitrate prior to induction of labor.

OBJECTIVE: To examine the effectiveness and safety of outpatient vaginal administration of isosorbide mononitrate (IMN) to induce cervical ripening. METHODS: A prospective, double-blind, placebo-controlled, randomized clinical trial was conducted on 102 singleton term pregnant women with unfavorable cervices who were randomly assigned to receive outpatient intravaginal IMN or placebo before admission for induction of labor. The main outcome variable was time from hospital admission to delivery. Secondary outcomes included fetal and maternal morbidity, labor characteristics, and incidence of cesarean delivery. RESULTS: The admission-delivery interval was 13.45+/-6.63 and 20.12+/-8.19 h (P=0.0001) for the IMN and placebo groups, respectively. Of the IMN patients 62.75% needed prostaglandins for cervical ripening versus 90.2% with placebo (P=0.002). The incidence of tachysystole was significantly lower in the IMN group (P<0.05) but there were no significant differences in cesarean delivery rate, neonatal outcomes, and incidence of hyperstimulation. CONCLUSIONS: Outpatient use of IMN resulted in shorter admission to delivery interval, and was associated with less prostaglandin use and lower incidence of uterine tachysystole.     

Oxytocin augmentation of labor and perinatal outcome in nulliparas

Recent pharmacologic observations in vivo suggest the use of a lower starting dose (0.5-0.1 mU/minute) of oxytocin and a longer interval between dose augmentations (30-60 minutes) than previously advocated. In this study, a high-dose oxytocin protocol was used to augment nonprogressive labor in normal nulliparous women. The rate of oxytocin infusion started at 6 mU/minute and was increased by 6 mU/minute every 15 minutes to a maximum dose of 40 mU/minute. Charts were reviewed of 1080 nulliparous women for whom the principles of active management of labor were followed and delivery occurred between March 1, 1986 and December 31, 1988. Four hundred fifty-six who required oxytocin augmentation in labor were compared with 624 who did not receive oxytocin. There were no statistically significant differences in birth asphyxia or perinatal morbidity.     

Rate of increase in oxytocin dose on the outcome of labor induction.

OBJECTIVE: To compare the efficacy and safety of arithmetic and geometric increases in oxytocin infusion dosage during induction of labor. METHODS: A total of 120 pregnant women requiring induction of labor at term were randomly assigned to receive oxytocin at dosages increasing arithmetically or geometrically. Maternal demographics, labor delivery data, and newborn outcomes were compared. The setting was the maternity unit of the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria. RESULTS: The mean maximum rates of oxytocin delivery needed to achieve adequate uterine contractions were similar in the 2 groups (24.66+/-8.34 mU/min vs. 26.38+/-8.77 mU/min, P=0.24). Labor duration was significantly shorter in the geometric progression group (496.33+/-54.77 min vs. 421.34+/-63.91 min, P<0.001). There were no differences in the rates of cesarean sections, vaginal deliveries, or uterine hyperstimulation, or in neonatal outcomes. CONCLUSION: A geometric rise in the rate of oxytocin infusion delivery reduced the duration of labor without affecting the rates of cesarean sections and uterine hyperstimulation, or newborn outcomes.