European Review for Medical and Pharmacological Sciences 2011; 15: 759-763 A randomized clinical trial to compare the efficacy of different doses of intravaginal misoprostol with intracervical dinoprostone for cervical ripening and labor induction P. SAXENA, M. PURI, M. BAJAJ, A. MISHRA, S.S. TRIVEDI Department of Obstetrics and Gynecology, Lady Hardinge Medical College and Shrimati Sucheta Kriplani Hospital, New Delhi (India) Abstract. – Objectives: To compare the method for the purpose of vaginal delivery. In- efficacy of 25 vs. 50 µg of intravaginal misopros- duction of labor with an unfavorable cervix is of- tol vs. intracervical dinoprostone for cervical ripening and labor induction. ten difficult. Use of prostaglandin preparations is Materials and Methods: 210 women with Bish- recognized and accepted for induction of labour. op’s score <6 were randomized into 3 groups of 70 The commonly used agents for induction of labor each to receive 6 hourly doses of either 25 or 50 µg are dinoprostone gel and misoprostol tablets1,2. of intravaginal misoprostol or 0.5 mg intracervical Dinoprostone is expensive, requires refrigeration, dinoprostone to maximum of 3 doses and out- needs to be instilled in the cervix and many pa- come parameters were compared. tients require additional oxytocin augmentation Results: Induction to vaginal delivery interval was significantly lower (p<0. 05) for 50 µg during induction of labor. Misoprostol is cheap, (13.8±6.62 hours) as compared to 25 µg misopros- does not require refrigeration and can be given tol (16.4±7.34 hours) or dinoprostone group through vaginal, oral or sublingual routes. Nu- (16.3±7.49 hours). Maximum improvement (p<0.05) merous dosage schedules and time intervals have in Bishop’s score and minimum oxytocin require- been described in literature1-5 for inducing labor ment (p<0.05) was seen with misoprostol 50 µg. No with misoprostol. Higher doses and short dosage significant difference was observed for women de- livering vaginally within 24 hours (93.8 vs. 89.7 vs. intervals can lead to maternal and fetal complica- 85.4%), patients delivering after one dose (24.3 vs. tions while lower doses may not achieve the de- 21.4 vs. 20%), cesarean deliveries, fetal outcome, sired outcome. Therefore, in order to find the op- complications like hyperstimulation and fetal heart timal regimen with minimal side effects, we abnormalities for the 50 vs. 25 µg misoprostol vs. compared the efficacy of 25 μg vs. 50 μg of in- dinoprostone group. µ travaginal misoprostol vs. dinoprostone gel for Conclusion: Intravaginal misoprostol 50 g cervical ripening and induction of labor. administered 6 hourly appears to be most effec- tive as it has least induction to delivery time, has maximum improvement in Bishop’s score, least oxytocin requirement without any increase in complication rate. Material and Methods Key Words: This prospective randomized clinical trial was Misoprostol 50 µg, Misoprostol 25 µg, Dinopros- conducted in the Department of Obstetrics and tone, Cervical ripening, Labor induction. Gynecology of a tertiary level Hospital after ob- taining Institutional ethical clearance. A total of 210 women with Bishop’s score <6 were ran- domized into 3 groups of 70 each to receive 6 Introduction hourly either 25 μg or 50 μg of intravaginal misoprostol or 0.5 mg intracervical dinoprostone. Induction of labour means initiation of uterine The inclusion criteria included women with contractions after the period of viability by any singleton, term pregnancy with intact mem- Corresponding Author: Pikee Saxena, MD; e-mail: [email protected] 759 P. Saxena, M. Puri, M. Bajaj, A. Mishra, S.S. Trivedi branes, cephalic presentation, with an unfavor- the patient to left lateral, starting oxygen inhala- able cervix (Bishop’s <6) and an amniotic fluid tion, Ringer lactate infusion and removing any index (AFI) of >5. The exclusion criterion in- remnants of the drug. cluded women with premature rupture of mem- Once the patient went into active phase of la- branes, multiple pregnancy, severe intrauterine bor, routine intra-partum management was per- growth retardation (IUGR), non cephalic presen- formed without regard to treatment allocation. tation, cephalopelvic disproportion, previous Development of potential adverse events was as- uterine scar or history of uterine perforation, al- sessed at every 6 hours by using a standardized lergy to prostaglandin, Bishop’s ≥6, severe symptom questionnaire which included symp- oligoamnios or any medical disorder except ges- toms like continuous lower abdominal pain, nau- tational diabetes mellitus (GDM) controlled on sea, vomiting, hyperthermia, dizziness, fatigue, diet and mild pregnancy induced hypertension diarrhea, headache and palpitation. (PIH). Outcome parameters evaluated were induction All the recruited participants were fully in- to delivery interval, change in Bishop’s score after formed about the nature, scope and the potential first instillation, number of patients delivering risks of the study which was followed by an in- vaginally within 24 hours of induction or after first formed consent. Randomization into 3 groups dose of drug, requirement of oxytocin for augmen- was performed by computer generated random tation of labour, occurrence of tachysystole and hy- numbers. Thorough general, systemic and obstet- persystole, mode of delivery along with indications ric examination was done. The Bishop’s score for cesarean section. For fetal outcome, fetal heart was recorded. An ultrasound was done to verify rate abnormalities, passage of meconium and Ap- the period of gestation, calculate AFI. Non stress gar score at 5 minutes were evaluated. test was done before instilling the allocated drug. Power analysis was performed on the basis of Fetal heart rate tracings were taken for 30 min previous studies. Considering a between groups immediately after insertion and uterine contrac- difference6 of 20% for the percentage of patients tions were monitored. Progress of labour was delivering within 24 hours after 50 µg misopros- monitored by observing uterine contractions and tol and dinoprostone gel instillation, a sample descent of head. Fetal heart pattern was recorded size of 55 in each group was calculated with 95% by intermittent auscultation during the first stage power at α = 0.05. We recruited 70 patients in and by continuous external electronic fetal heart each group. monitoring in high risk patients. A repeat vaginal examination was done after 6 hr in each group Statistical Analysis and Bishop’s score was reassessed. A repeat in- The statistical analysis was performed on the sertion was done if Bishop’s score was ≤6 and a Statistical Package for the Social Sciences (SPSS maximum of 3 doses were instilled for each version 10) software (SPSS Inc., Chicago, IL, group. Artificial rupture of membranes was per- USA) with the use of chi square test for categori- formed if the cervix was >3 cm dilated. Intra- cal variables and Anova to compare between venous oxytocin was administered only if active groups for continuous variables. labor was not established despite maximum num- ber of dosages. Oxytocin was administered 6 hours after instillation of the last dose of dino- prostone or misoprostol if required. Fetal heart Results rate (FHR) was assessed for any bradycardia [fe- tal heart sound (FHS) <110/min], tachycardia Two hundred and ten women were recruited (>150/min), late deceleration, or variable decel- and divided into 3 groups of 70 each to receive eration pattern. Uterine activity was evaluated for intravaginal misoprost 25 μg (Group 1) or 50 μg tachysystole, hypertonicity, or hyperstimulation. (Group 2) or intracervical dinoprostone (Group Tachysystole was defined as at least six contrac- 3). Number of nulliparous women was 47 tions in 10 min for 20 min, and hypertonus was (67.1%), 39 (55.7%) and 44 (62.8%) in group 1, considered if a single contraction was felt lasting 2 and 3 respectively. The average period of gesta- for >2 min. Hyperstimulation was diagnosed if tion was 39.8±1.0 weeks, 39.05±2.5 weeks and there was associated abnormal FHR pattern. Any 39.8±1.2 weeks in group 1, 2 and 3 respectively. patient with hyperstimulation was treated by dis- Indications for induction of labor for each group continuing oxytocin if it was on flow, positioning were comparable as shown in Table I. 760 Misoprostol 50 vs. 25 µg vs. dinoprostone for cervical ripening and labor induction Table I. Indications for induction of labor. Indication Misoprostol 25 µg Misoprostol 50 µg Dinoprostone n = 70 (Gr. 1) n = 70 (Gr. 2) n = 70 (Gr. 3) > 40 weeks 54 59 56 PIH 7 4 6 Gestational diabetes mellitus 1 1 Nil Cholestasis 2 2 1 IUGR 3 1 3 Oligoamnios Nil 1 3 Decreased fetal movements 3 2 1 Labor outcome parameters are depicted in Comparison of Bishop’s score before and after Table II. Number of vaginal deliveries within 24 first application of drug is shown in Table III. Ini- hours occurred in 44/49 (89.7%) patients of tial mean Bishop’s score of group 1 was 2.20±1.33 group 1, 46/49 (93.8%) of group 2 and in 41/48 which improved significantly to 3.46±2.69 (85.4%) of group 3. Induction to vaginal delivery (p<0.000) after first application of misoprostol 25 interval was significantly lower (p<0. 05) for µg. Mean Bishop’s score of group 2 improved group 2 (13.8±6.62 hrs) as compared to group 1 from 2.38±1.4 to 4.64±2.8 (p<0.000) and of group (16.4±7.34 hrs) and group 3 (16.3±7.49 hrs). The 3 improved from 2.9±1.2 to 4.35±1.15 (p<0.000) difference in induction to vaginal delivery inter- after 6 hours. The increase in Bishop Score was val between group 1 and 3 was statistically not- significantly more for group 2 vs.