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.     

Membrane sweeping to induce labor in low-risk patients at term pregnancy: A randomised controlled trial

Objective.?To evaluate the efficacy of membrane sweeping at initiation of labor induction in low-risk patients at term pregnancy (38–40 gestational weeks).

Methods.?This prospective study included 351 antenatal women who were randomly assigned to one of two groups: a sweeping of the membranes group (n?=?181) and a no sweeping control group (n?=?170). The primary outcome measure was the proportion of women who entered spontaneous labor within 1 week of entry into the study. Secondary outcome measures included mode of delivery and maternal and fetal complications.

Results.?Five patients (two in the sweeping group and three in the no sweeping group) were excluded from the study because of breech presentation at labor. There were no statistically significant differences between the two groups regarding maternal age, parity or Bishop score. The proportion of subjects who entered spontaneous labor before 41 weeks of gestation was significantly different between the two groups (p?<?0.0001). The mode of delivery did not differ significantly between the groups and there was no statistically significant difference in maternal or fetal complications.

Conclusions.?Sweeping of membranes is a safe method to reduce the length of term in pregnancy and the incidence of prolonged gestation in a low-risk population. There is no evidence that sweeping the membranes increases the risk of maternal or neonatal adverse outcomes.     

Effect of membrane sweeping at term pregnancy on duration of pregnancy and labor induction: a randomized trial

AIM: To evaluate the efficacy of sweeping of fetal membranes for induction of labor in uncomplicated term pregnancies. METHODS: A randomized controlled trial was performed in 122 pregnant women beyond 39 weeks of gestation with no complications. The women were assigned to have their membranes swept or not (controls) for labor induction. The main outcome measures included duration of pregnancy and possible complications of sweeping of membranes, including rupture of membranes, postpartum infections, and vaginal bleeding. RESULTS: Twenty-one patients did not give birth in our hospital and were, therefore, excluded from the study; 101 women completed the study (51 patients in the control group and 50 women in the study group). There were no statistically significant differences in maternal age, parity, birth weight, and Bishop score in the two groups. The mean interval between sweeping (stripping) and vaginal examination until delivery was 7.7 +/- (SD) 6.9 and 7.1 +/- 5.6 days in the sweeping and in the control group, respectively (p = 0.61). Of the 101 pregnant women, only 6 patients had premature rupture of membranes (2 in the sweeping group and 4 in the control group). There were no statistically significant differences between these individuals (p = 0.68). Significant vaginal bleeding was not observed in the two groups. Meconium-stained amniotic fluid was seen in 13 women: 8 in the sweeping group and 5 in the control group. There were no statistically significant differences among the women who had meconium-stained fluid in case and control groups (p = 0.39). There were no differences between women who had puerperal fever (3 in the sweeping group and 2 in the control group; p = 0.68). 12 of the 101 women (6 in each group) had cesarean section performed, but there was no difference between the two groups. CONCLUSION: Sweeping of membranes at 39 weeks of gestation has no significant clinical effect on the duration of pregnancy.     

Misoprostol in labor induction

The efficacy of a new dosing regimen of misoprostol, a recently introduced labor-inducing agent, was studied. Fifty-eight patients received 50 microg of misoprostol intravaginally and the dose was repeated every 3 hours until uterine contractions begin. Those who had an adequate contraction pattern, defined as three contractions in 10 minutes, were not given the repeat dose. Oxytocin augmentation, but not further misoprostol doses, was used in patients with an inadequate contraction pattern. The maximum total daily dose was 200 microg. The patients had the mean age of 28.9 +/- 5.4, the mean gestational age of 211.8 +/- 46.6 days, the mean gravidity of 2.5 +/- 1.2, the mean parity of 0.9 +/- 0.9 and the mean initial Bishop score of 1.6 +/- 1.8. The mean required dose of misoprostol was 120.5 +/- 54.7 microg and 10 of 58 patients required oxytocin augmentation. The mean induction of labor to delivery time was 701.5 +/- 404.0 minutes. When 3 cases who gave birth with caesarean section were excluded, the interval was 708.4 +/- 407.2 minutes. The mean 5th minute Apgar score of the newborns was 8.2 +/- 2.5. Two patients developed tachysystole after the second dose of misoprostol and were managed with vaginal irrigation and O2 supplementation successfully. Slight nausea and vomiting in 2 patients were the other adverse reactions. Our findings revealed that, 50 microg intravaginal misoprostol, combined with oxytocin augmentation when necessary, appears to be an effective and safe method of labor induction.     

Oral labor induction with PGE2-tablets

Orally administered PGE2 in tablet form was used to induce labour in a prospective trial on 57 patients. The prostaglandin was given in separate-hourly-dosis of 0,5 to 1,5 mg. The success rate of this oral induction was 93%. Frequency of acidotic and/or clinically depressed newborns and the incidence of active delivery reflected the unselected population. A precipitant labour was noted in one patient, while 23% showed symptoms of gastrointestinal side effects which were seen to be dosage dependent.     

Elective induction of labor

Induction of labor rates have more than doubled nationwide in the past 15 years. The increase in medically induced inductions was slower than the overall increase, suggesting that inductions for marginal or elective reasons rose more rapidly. Elective inductions seem to account for at least half of all inductions and 10% of all deliveries. Whether the experience of an elective induction is satisfactory to the patient, obstetrician, and intrapartum crew warrants more widespread attention. Cesarean rates are high for nulliparas undergoing an induction with an unfavorable cervix. Prospective studies are limited or nonexistent to recommend induction of labor for elective or marginal indications. Until more prospective work is performed, it will be difficult to evaluate the true impact of the elective induction of labor on population-wide cesarean delivery rates. Strategies for increased obstetrician awareness are proposed through practice guidelines and through clinical research trials.     

Oxytocin for labor induction

Induction of labor has increased from 9% to 18% of all U.S. deliveries in recent years. Several useful oxytocin induction protocols are available, both from the ACOG Practice Bulletin #10 and institutional sources. Higher-dose protocols tend to result in fewer cesarean deliveries for dystocia but more "fetal distress." There is no consensus as to which protocol is best, and the clinician is advised to understand the trade-offs involved and how those trade-offs could relate to the clinician's local situation. Given the availability now of prostaglandin agents for induction with an unfavorable cervix, the advantage of less hyperstimulation in low-dose oxytocin protocols may become increasingly important. The most important risks include hyperstimulation (frequent but usually brief and well-tolerated), failed induction (occasional and important), and uterine rupture in some studies (rare but dangerous). Pain was not a sensitive indicator of uterine rupture in a large 1989 study. Fetal heart rate changes were much more likely to herald uterine rupture in that study. Oxytocin's greatest weakness is that some patients will not respond well to it, especially with marked cervical unfavorability. However, given an individual patient whose uterus will respond adequately to this drug, oxytocin has the advantage of short half-life and the option for prompt cessation if desired. Intrauterine pressure catheters with oxytocin usage are usually well-worth their minor risks. Current ACOG literature lists induction of labor in the setting of one or more previous low-transverse cesarean deliveries as necessitating "special attention" and "close patient monitoring." The well-informed clinician will be familiar with the issues involved.