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.     

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.     

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.     

Oxytocin dose and the risk of uterine rupture in trial of labor after cesarean

OBJECTIVE: To examine the association between uterine rupture and oxytocin use in trial of labor after cesarean. METHODS: A case-control study was performed. Cases were all women with uterine ruptures who received oxytocin during a trial of labor after a single cesarean delivery within a 12-year period (n = 24). Four controls undergoing trial of labor after a single cesarean delivery were matched to each case by 500 g birth weight category, year of birth, and by induction or augmentation (n = 96). The study had an 80% power to detect a 40% increase in oxytocin duration or a 65% increase in total oxytocin dose. RESULTS: No significant differences were seen in initial oxytocin dose, maximum dose, or time to maximum dose. Although women with uterine ruptures had higher exposure to oxytocin as measured by mean total oxytocin dose (544 mU higher) and oxytocin duration (54 minutes longer), these differences were not statistically significant. Women with uterine rupture who received oxytocin were more likely to have experienced an episode of uterine hyperstimulation (37.5% compared with 20.8%, P =.05). However, the positive predictive value of hyperstimulation for uterine rupture was only 2.8%. CONCLUSION: Although no significant differences in exposure to oxytocin were detected between cases of uterine rupture and controls, the rarity of uterine rupture limited our power to detect small differences in exposure. In women receiving oxytocin, uterine rupture is associated with an increase in uterine hyperstimulation, but the clinical value of hyperstimulation for predicting uterine rupture is limited.     

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.     

A prospective randomized study comparing misoprostol and oxytocin for premature rupture of membranes at term.

OBJECTIVE: The aim of this randomized trial was to compare the efficacy and safety of vaginal misoprostol and oxytocin for cervical ripening and labor induction in patients with premature rupture of membrane (PROM) at term. METHODS: Ninety-seven women with PROM at term were assigned randomly to receive intravaginal misoprostol or oxytocin. The primary outcome measure was the induction-delivery interval. Secondary outcomes included the number of women who delivered vaginally within 12 hours of the start of the induction in the two groups, the cesarean, hyperstimulation, and failed induction rates, the mode of delivery, and the neonatal outcome. RESULTS: Forty-eight women were assigned to intravaginal misoprostol and 49 to oxytocin administration. The mean interval from induction to delivery was 10.61 +/- 2.45 hours in the misoprostol group and 11.57 +/- 1.91 hours in the oxytocin group (p = 0.063). The rates of vaginal delivery were 83.3% and 87.7% and cesarean delivery were 16.7% and 8.2% in the misoprostol and oxytocin groups, respectively. Neonatal outcomes were not significantly different. Of the cases, 8.3% in the misoprostol group and 8.2% in the oxytocin group revealed uterine contraction abnormalities. CONCLUSION: Our study demonstrates that, intravaginally, misoprostol results in a similar interval from induction of labor to delivery when compared to oxytocin.     

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.     

A prospective comparison of hourly and quarter-hourly oxytocin dose increase intervals for the induction of labor at term

Fifty-two women undergoing labor induction and vaginal delivery at term were randomized between two oxytocin infusion protocols, involving hourly versus quarter-hourly increases in dose. Potential differences were sought of duration of labor, amount of uterine activity generated, and amount of oxytocin required. Starting at 0.5 mU/minute, oxytocin infusion was increased regularly in small increments every hour or every 15 minutes, according to group assignment. No differences were observed in potentially confounding clinical and demographic factors between the groups, including time to ruptured membranes. There were no clinically or statistically significant differences found for the duration of any phase or stage of labor, quantitative assessment of uterine activity, incidence of hyperstimulation, or neonatal outcome. The average dose of oxytocin used was lower in the hourly than in the quarter-hourly, protocol (4.4 versus 6.7 mU/minute; P less than .005). Significantly fewer patients on the hourly protocol required a maximum infusion rate exceeding 8 mU/minute (P less than .05). More patients on the hourly protocol either had oxytocin discontinued completely or were maintained at 4 mU/minute or less during the active phase of labor (P less than .05 and P less than .001, respectively). We conclude that a slower rate of increase in oxytocin administration via continuous infusion results in no prolongation of any phase of induced labor, while permitting lower infusion rates of the drug.     

A comparison of orally administered misoprostol to intravenous oxytocin for labor induction in women with favorable cervical examinations

OBJECTIVE: The purpose of this study was to compare orally administered misoprostol with intravenous oxytocin infusion for labor induction in women with favorable cervical examinations (defined as a Bishop score of 6 or more). STUDY DESIGN: One hundred ninety-eight women with indications for labor induction and favorable cervical examinations were assigned randomly to receive oral misoprostol or oxytocin induction. Misoprostol, 100 mg, was administered every 4 hours up to 6 doses, or intravenous oxytocin was administered by standardized protocol. RESULTS: One hundred ten (55.6%) women received misoprostol; 88 (44.4%) received intravenous oxytocin. There was no statistically significant difference in the average interval from start of induction to vaginal delivery, being longer in the misoprostol group (789.4 +/- 510.2 minutes) than in the oxytocin group (654.0 +/- 338.2 minutes, P=.19, log-transformed data). Two women had tachysystole develop in each treatment group. More women in the misoprostol group experienced hyperstimulation (7/110, 6.4%) than in the oxytocin group (0/88, P=.02, Fisher exact test). Nine (8.1%) misoprostol-treated women and 8 (9.1%) oxytocin-treated women underwent cesarean deliveries (P=.82). There was a presumed uterine rupture in a misoprostol-treated multipara women. There were no statistically significant differences in neonatal outcomes between the groups. CONCLUSION: Oral misoprostol offers no benefit over intravenous oxytocin for labor induction in women with favorable cervical examinations. It is associated with a higher likelihood of uterine hyperstimulation and may increase the risk of uterine rupture.     

Pulsatile administration of oxytocin for augmentation of labor

In a randomized study, 94 patients with term pregnancies underwent augmentation of labor with either continuous or pulsed (every 8 minutes) intravenous oxytocin infusion. There were no significant differences with respect to the maternal characteristics, cervical dilatation and effacement, induction-to-labor interval, induction-to-delivery interval, cesarean section rate, analgesia for labor, or low Apgar scores. No hyperstimulation was noted in either group. In each group, 20% of the patients had dysfunctional labor patterns, with coupling and tripling of the uterine contractions. The mean +/- SEM oxytocin administered in the pulsed-infusion group was significantly lower than that in the continuous-infusion group (2.1 +/- 0.4 versus 4.1 +/- 0.4 mU/minute; P less than .001). The mean +/- SEM total amount of oxytocin administered was 1300 +/- 332 mU for the pulsed group and 1803 +/- 302 mU for the continuous group, indicating that lower amounts of oxytocin were required for pulsed administration. Our study demonstrates that pulsatile administration of oxytocin is similar in efficacy to our standard continuous oxytocin infusion and requires a lower total amount and rate of oxytocin administered, which may afford a greater margin of safety.     

Misoprostol for cervical ripening and labor induction in pregnancies with oligohydramnios

The efficacy and safety of misoprostol for cervical ripening and labor induction in patients with oligohydramnios was investigated. 57 pregnancies with oligohydramnios and 58 cases with a normal amniotic fluid volume (controls) were enrolled in this prospective trial. All patients received 50 microg of intravaginal misoprostol every 5 h. Primary outcomes were: cesarean section rate; induction to delivery time; oxytocin augmentation; uterine hyperstimulation; meconium passage; fetal heart rate (FHR) changes; fetal distress requiring delivery, and Apgar scores. There were no differences in the mean time to delivery, cesarean section rate, oxytocin augmentation or Apgar scores. The mean induction to delivery time in oligohydramnios and control groups were, 11 h 43 min and 11 h 18 min, respectively (p > 0.05). FHR changes were observed in 26.3% of oligohydramnios group and 32.7% of control group (p > 0.05). There was no statistically significant difference in the cesarean section rate and the uterine hyperstimulation between the 2 groups. These data suggest that misoprostol can be used as an effective agent for cervical ripening and labor induction in pregnancies with oligohydramnios without increasing the risk for perinatal outcome, compared to those with normal amniotic fluid volumes.     

Cervical ripening and labor outcome with preinduction intracervical prostaglandin E2 (Prepidil) gel

Delivery with an unfavorable cervix using oxytocin is frequently unsuccessful. Used widely in Europe and increasingly in this country, locally applied prostaglandin E2 appears to improve labor induction. The present study prospectively evaluated the efficacy and safety of a prostaglandin gel (0.5 mg) placed intracervically. The use of the gel, when compared to a control group who received no pretreatment prior to labor induction, resulted in improved Bishop scores (7.5 +/- 1.0 vs. 1.8 +/- 0.3, P less than 0.0001), reduced induction to delivery intervals (10.1 +/- 2.1 vs. 20.6 +/- 2.0 hours), reduced oxytocin infusion duration (10.0 +/- 2.1 vs. 20.0 +/- 2.3 hours. P less than 0.0001) resulting in a lower cesarean delivery rate, 26 vs. 47 per cent (P greater than 0.05). Thirty-two per cent of patients receiving the prostaglandin gel labored and delivered within 12 hours and required no oxytocin. In addition, the use of prostaglandin E2 gel appeared safe in that no patient experienced an untoward reaction. Two cases of uterine hyperstimulation occurred that required uterine tocolysis but were not associated with fetal distress. The use of prostaglandin gel appears to be a safe and effective method to improve cervical inducibility in patients undergoing induction for a variety of maternal and fetal indications.     

Prospective randomized study of oxytocin discontinuation after the active stage of labor is established

AIM: To investigate the effects of discontinuing oxytocin infusion on labor outcomes once the active stage of labor is established. METHODS: This is a prospective study involving 342 pregnant women who underwent labor induction at our institution. Patients were randomly divided into two groups. In the first group oxytocin was discontinued at the beginning of the active phase of labor, and in the other group, oxytocin was administered until delivery. RESULTS: Duration of the active phase and the second stage of labor were longer in the oxytocin-discontinued group; however, this was not statistically significant. The rate of uterine hyperstimulation was significantly higher in oxytocin-continued group (P < 0.05). The total cesarean delivery rate for the oxytocin-continued group was 6.9%, compared with 4.8% in the oxytocin-discontinued group (P > 0.05). CONCLUSION: Discontinuing oxytocin infusion once the active stage of labor is established may be an alternative protocol in developing countries where the conditions for fetal monitoring and emergency cesarean section are less available.     

Membrane sweeping in conjunction with labor induction

OBJECTIVE: To determine whether cervical membrane sweeping (stripping) during induction of labor is beneficial.METHODS: We compared outcomes of labor after induction in pregnant women at term in a randomized trial. Women were assigned to having their membranes swept or not during induction. Outcome measures included duration of labor, maximum dose of oxytocin used, induction-labor interval, and mode of delivery.RESULTS: We recruited 130 nulliparas (64 sweep, 66 nonsweep) and 118 multiparas (60 sweep, 58 nonsweep). Among nulliparas who received intravaginal prostaglandin (PG) E(2) and oxytocin, those who had simultaneous sweeping had significantly shorter mean (+/- standard error of mean) induction-labor interval (13.6 +/- 1.4 versus 17.3 +/- 1.2 hours, P =.048), lower mean maximum dose of oxytocin (6.8 +/- 0.8 versus 10.35 +/- 1.1 mU/minute, P =.01), and increased normal delivery rates (vaginal delivery 83. 3% versus 58.2%, P =.01). Sweeping also had a favorable effect on nulliparas who received oxytocin alone (mean induction-labor interval 5.8 +/- 3.1 versus 11.2 +/- 3.6 hours, P =.04; mean maximum dose 8.8 +/- 1.3 versus 16.3 +/- 1.9 mU/min, P =.01). Those differences were limited to women with unfavorable cervices. There were no differences in any outcome measures in multiparous women. CONCLUSION: Sweeping of the membranes during induction of labor had a beneficial effect on labor and delivery, which appeared to be limited to nulliparas with unfavorable cervices who needed cervical priming with PGE(2).     

Pulsatile administration enhances the effect and reduces the dose of oxytocin required for induction of labor

Pulsatile administration of oxytocin was compared with continuous infusion of oxytocin for induction of labor in pregnant rats. The dosages consisted of intravenous injections of 0, 2.5, and 5 mU oxytocin every 10 minutes and intravenous infusion of 1 mU/minute of oxytocin in 0.9% sodium chloride. These doses are within the range of endogenously secreted pulses. All treatments began on day 22 at 2 p.m. and continued for 8 hours. Pulsatile administration resulted in a marked reduction in the dose of oxytocin required to induce labor. Using 5 mU pulses, birth was induced with 18.4%, and using 2.5 mU pulses, with 24% of the dose needed using continuous infusion. Parturition was advanced by 12 hours on the average by oxytocin treatment, but no significant differences were observed between the various oxytocin dosage regimens in this regard or in regard to gestation length, induction-delivery interval, duration of delivery, or the proportion of living or dead pups. Significantly more uterine activity was induced with each mU of oxytocin using pulsatile administration than using continuous infusion. There was no evidence for down-regulation of oxytocin receptors during a continuous infusion of oxytocin. We postulate that the greater efficacy of oxytocin pulses to induce uterine activity and delivery in comparison to continuous infusions is due to a more effective stimulation of prostaglandin F2 alpha release from the decidua. The amount of oxytocin needed for induction of labor with 2.5 mU pulses was similar to the decrease in neurohypophyseal oxytocin content during the first stage of spontaneous labor, and uterine activity elicited was also similar to that observed during spontaneous labor.(ABSTRACT TRUNCATED AT 250 WORDS)     

Induction of labor with 50 and 100 microg of misoprostol: comparison of maternal and fetal outcomes

OBJECTIVE: The aim of this randomized controlled study was to compare the efficacy and the safety of different regimens of misoprostol for labor induction. MATERIALS AND METHODS Eligible women received intravaginal 100 microg, every 6 h or 50 microg every 4 h. Treatment continued until: (1) dilatation >3 cm; (2) rupture of membranes (artificial); (3) signs of uterine hyperstimulation; (4) adequate contraction pattern (three contraction/10 min). Managing clinician might use oxytocin during labor. Cesarean section rate was the main outcome that was considered variably. Other outcome measures were neonatal outcome (Apgar scores, meconium staining, and umbilical artery pH) and induction to delivery interval. RESULTS: A total number of 72 women received either misoprostol 100 microg (n=37), or 50 microg (n=35) randomly. The two groups had similar mean Bishops scores at induction (4.10+/-2.4 versus 4.2+/-2.1; P=0.85), rates of nulliparity, use of epidural anesthesia, and oxytocin augmentation. In two groups the number of doses of misoprostol used was similar (1.6+/-0.5 versus 1.7+/-0.3) CONCLUSION: There was not any difference between the two groups in the mean+/-S.D. time to delivery (h) and cesarean rate. Likewise, there was not a significance between two groups in the rates of 5 min Apgar score, and of meconium passage.     

Oral, vaginal and sublingual misoprostol for induction of labor.

OBJECTIVE: To evaluate the effectiveness and safety of different administration routes of misoprostol for induction of labor. METHOD: PubMed, Cochrane Library and EMBASE searches were carried out using the keywords oral, vaginal, sublingual, buccal, misoprostol, labor induction, identifying randomized case-controlled trials comparing different routes for giving misoprostol to induce labor, published in English between 1994 and 2004. RESULTS: Seventeen studies (3549 participants) were included. Compared to vaginal administration, oral misoprostol was associated with higher failure rates for achieving vaginal delivery within 24 h (odds ratio (OR) 1.61, 95% confidence interval (CI) 1.23-2.10), higher rates of uterine hyperstimulation without fetal heart rate (FHR) changes (OR 2.21, 95% CI 1.12-4.34) and lower cesarean section rates (OR 0.74, 95% CI 0.56-0.97). A lower dose of oral misoprostol (50 microg) compared to the 25-50 microg administered vaginally was associated with a higher rate of vaginal delivery not being achieved within 24 h (OR 3.60, 95% CI 2.10-6.18), more need for oxytocin augmentation (OR 2.19, 95% CI 1.65-2.92), less uterine hyperstimulation both without FHR changes (OR 0.58, 95% CI 0.42-0.80) and with FHR changes (OR 0.34, 95% CI 0.17-0.67) and fewer cesarean sections (OR 0.69, 95% CI 0.51-0.91). Compared to vaginal administration, buccal misoprostol resulted in a higher rate of failure to achieve vaginal delivery after 24 h, more frequent uterine hyperstimulation and lower rates of cesarean section, but these differences were not significant. When 50 mug of misoprostol used sublingually was compared to oral administration, the sublingual misoprostol was associated with less failure to achieve vaginal delivery after 24 h, less oxytocin augmentation and reduced cesarean section, but none of the differences were statistically significant. CONCLUSIONS: Vaginal misoprostol appears more effective than the equivalent dosage administered orally. However, the vaginal route appears to be associated with a higher risk of uterine hyperstimulation. Sublingual misoprostol seems an effective route of administration, but a lack of data necessitates more clinical trials to establish the effectiveness and safety of the buccal/sublingual route.     

Oxytocin discontinuation after the active phase of labor is established

Despite the widespread usage of oxytocin, there is still no consensus on its mode of administration. The scope of the present meta-analysis was to assess the effect of oxytocin discontinuation after the active phase of labor is established on maternal fetal and neonatal outcomes. We searched Medline, Scopus, Popline, ClinicalTrials.gov and Google Scholar databases. Eight studies were finally retrieved, which involved 1232 parturient. We observed significantly decreased rates of cesarean sections among parturient that discontinued oxytocin (OR 0.51, 95% CI 0.35, 0.74) as well as decreased rates of uterine hyperstimulation (OR 0.33, 95% CI 0.19, 0.58). Similarly, cases of non-reassuring fetal heart rates were fewer among women that did not receive oxytocin after the establishment of the active phase of labor (OR 0.63, 95% CI 0.41, 0.97). Keeping in mind the aforementioned maternal and neonatal adverse effects that seem to result from infusion of oxytocin until delivery, future practice should aim towards its discontinuation after the establishment of the active phase of labor, as it does not seem to influence the total duration of labor. Future studies should aim towards specific populations of parturient in order to clarify whether different approaches are needed.     

Induction of labor with misoprostol in pregnancies with advanced maternal age

OBJECTIVE: The objective was to compare the efficacy and complications of intravaginal misoprostol application with oxytocin infusion for induction of labor in advanced aged pregnancies with a Bishop score of < 6. STUDY DESIGN: A hundred advanced aged (> or = 35 years) pregnant patients with a Bishop score of < 6 were randomized into two groups. The first group (50 patients) received 50 microg intravaginal misoprostol four times with 4 h intervals and the second group received oxytocin infusion for induction of labor starting from 2 mIU/min and was increased every 30 min with 2 mIU/min increments up to a maximum of 40 mIU/min. The time from induction to delivery, the route of delivery, fetal outcome, and maternal complications were recorded. Statistical analyses were performed using the Mann-Whitney U, Chi-squared and t tests to determine differences between the two groups. A p value < or = 0.05 was considered significant. RESULTS: Misoprostol was superior for induction of labor in advanced aged pregnancies with Bishop score of < 6, as the mean time from induction to delivery was 9.61 +/- 4.12 h and 11.46 +/- 4.86 h in the misoprostol and oxytocin groups respectively, with a significant difference between the groups (p = 0.04). The rate of vaginal delivery was higher in the misoprostol group (84.0%) than in the oxytocin group (80.0%), but the difference did not reach significance (p = 0.60). The rates of placental abruption and postpartum hemorrhage were similar in both groups and no cases of uterine rupture occurred. The 1- and 5-min mean Apgar scores were 6.98 +/- 1.17 to 9.08 +/- 0.99 and 6.88 +/- 1.81 to 9.00 +/- 1.35 in the misoprostol and oxytocin groups respectively, with no significant differences between the groups (p = 0.74, p = 0.83). No cases of asphyxia were present. The rate of admission to the neonatal intensive care unit was similar in both groups. CONCLUSION: Intravaginal misoprostol seems to be an alternative method to oxytocin in the induction of labor in advanced aged pregnant women with low Bishop scores, as it is efficacious, cheap, and easy to use. But large studies are necessary to clarify safety with regard to the rare complications such as uterine rupture.     

Management of uterine hyperstimulation with concomitant use of oxytocin and terbutaline

The purpose of this study was to evaluate the efficacy of the concomitant use of subcutaneous terbutaline and oxytocin for the management of uterine hyperstimulation. Patients in active labor receiving intravenous oxytocin who developed uterine hyperstimulation were randomly assigned to receive either oxytocin discontinuation or administration of subcutaneous terbutaline while maintaining the oxytocin infusion. Time to resolution of hyperstimulation was the primary end point. Twenty-nine patients were enrolled. The most frequent types of hyperstimulation were tachysystole (26%) and mixed patterns (26%). Resolution time was significantly shorter in the combination therapy versus control ( P = 0.002). Persistence of hyperstimulation 15 minutes after intervention was seen in 53% of the women in the control group versus 0% of the women in the study group. No significant differences were noted in the Apgar scores, rates of cesarean sections, or chorioamnionitis. In the management of uterine hyperstimulation, subcutaneous terbutaline without discontinuation of oxytocin is more effective than the traditional approach of oxytocin discontinuation.