Induction of Labor in Post-Term Nulliparous and Parous Women – Potential Advantages of Misoprostol over Dinoprostone

Abstract

We undertook a prospective cohort study to compare the effectiveness and safety of 50 µg misoprostol versus 3 mg dinoprostone in two vaginal doses 6 hours apart, followed if necessary by oxytocin for labor induction in low-risk post-term (> 40 weeks) pregnancies with unfavorable cervix (Bishop score ≤ 6). Methods: Labor induction and subsequent management were conducted using a standardized protocol. The primary outcome of the study was labor induction rate. Secondary outcomes included mode of delivery, time interval from induction to delivery, maternal complications and neonatal outcome. Results: 107 patients received misoprostol (Group A) and 99 patients received dinoprostone (Group B). Compared with group A, more women in Group B needed a second vaginal dose of prostaglandin or oxytocin infusion in order to proceed to labor (21.5 vs. 43.4 %; p = 0.01). Misoprostol alone as a single or double vaginal dose was more effective than dinoprostone alone in inducing labor without oxytocin administration (85.0 vs. 50.4 %; p = 0.04). Overall, the rate of successful induction of labor did not differ between groups (91.6 vs. 85.8 %; p = 0.75). Vaginal delivery, operative vaginal delivery and Caesarean section rates were not significantly different. Time interval from induction to delivery however, was shorter for Group A (median 11 hours vs. 14.1 hours; p < 0.001). Though emergency Caesarean section due to fetal distress was more frequent in Group A (16.8 vs. 4.0 %; p = 0.007), low Apgar scores < 7 and NICU admissions did not differ significantly. Maternal complications, mostly not serious, were higher in Group A (31.8 vs. 2.0, p < 0.001). Conclusion: Misoprostol is a more effective agent than dinoprost in post-term pregnancy for labor induction with few maternal adverse effects.

Obstetric outcomes of pre-induction of labor with a 200 μg misoprostol vaginal insert

“…The results of this study concerning average age, parity and duration of pregnancy are comparable to the results reported in literature [4,6,21,22]. Yet, similarly to studies of Wing et al, Tsicouras et al or that of Kosińska-Kaczyńska et al, in our study the primigravidas prevail (65-82%), which is associated with the cervix being more immature in that subgroup, hence more often selected for pre-induction [2,3,7,23]. To support this, we show that the Bishop score in our study was significantly higher compared to the multiparas subgroup.…”

“…Despite the confirmed effectiveness of misoprostol in labor pre-induction, there considerations regarding risk of causing tachysystole, hyperstimulation, meconium-stained fluids or cardiotocographic abnormalities [8,17,18,[22][23][24]29]. In our study we recorded only 2% of cases with tachysystoly, same for hyperstimulation.…”

“…The most common extra drugs used in our study were oxytocin (56% of cases) and Fenoterol (19% of cases), both used more commonly in primigravidas. There are many studies confirming a less frequent use of drugs in the setting of MVI [3,10,14,17,20,23]. Since the rate of deliveries in our clinic was high, duration of hospitalization was short and all our patients were discharged within 2-4 days.…”

“…Most of researchers believe that labor induction is associated with higher operative rates and induction failure [5,9]. Many authors focus on the increased caesarean section rate in the setting of labor induction [23,27,28]. The Genesis study involving 2336 patients confirms a higher caesarean section rate in the primigravidas with induced labor compared to spontaneous labor (31% vs. 36%) [27].…”

Intracervical foleys catheter: Can it serve as an alternative to standard pharmacological method of cervical ripening?

“…2 In pregnant women with an unripe cervix, cervical ripening can be achieved by mechanical, surgical or pharmacological means. 3,4 The commonest protocol for preinduction cervical ripening is intracervical instillation of a prostaglandin (PGE2-Dinoprostone gel). 5 Despite being a commonly adopted procedure, prostaglandin gel has to be refrigerated for storage, it is contraindicated in patients of asthma and those allergic to prostaglandins, incur a high risk of uterine hyperstimulation and a relatively higher cost of treatment.…”