A comparison between labor induction with only Dilapan-S and a combination of mifepristone and Dilapan-S in nulliparous women: a prospective pilot study

Synthetic Osmotic Dilators for Pre-Induction Cervical Ripening - an Evidence-Based Review

Mechanical methods have gained growing interest for pre-induction cervical ripening in women with an unripe cervix, since they have a better safety profile compared to prostaglandins. Balloon catheters have been the gold standard method for decades, while there was a lack of data on synthetic osmotic cervical dilators. Not until 2015, when Dilapan-S was approved by the Food and Drug Administration (FDA) for induction of labor, numerous studies have been published on the use of Dilapan-S in this field. The rate of vaginal deliveries associated with the use of Dilapan-S ranges from 61.6 to 81.7%, and no serious complications needing further interventions have been reported to this date. Dilapan-S was shown to be as effective as the Foley balloon catheter as well as the 10 mg PGE 2 vaginal insert and orally applied misoprostol (25 µg every 2 hours) in achieving vaginal delivery, but patient's satisfaction during the cervical ripening process was significantly higher compared to the other methods and the rate of uterine hyperstimulation was significantly lower compared to prostaglandins (PGs). Minor complications (e.g. vaginal bleeding) associated with the use of Dilapan-S were < 2%, and maternal infectious morbidity was not higher compared to Foley balloon and vaginal PGE 2 or misoprostol. Due to these beneficial properties Dilapan-S might be an ideal option for outpatient cervical ripening, as shown in a recent randomized clinical trial comparing inpatient to outpatient cervical ripening. Furthermore, according to the manufacturers' product information, Dilapan-S is the only cervical ripening method that is not contraindicated for induction of labor in women with a previous cesarean section. Upcoming guidelines should consider synthetic osmotic cervical dilators as an effective and safe method for cervical ripening/induction of labor acknowledging that more evidence-based data are mandatory, particularly in patients with a previous cesarean section.

Comparison of outpatient with inpatient mifepristone usage for cervical ripening: A randomised controlled trial

Purpose

The efficacy and safety of using mifepristone for the preinduction/induction of labour (IOL) as the only method or in combination with others has been confirmed in observational and randomised trials. However, there are currently no studies comparing the efficacy and safety of using mifepristone for the preinduction of labour on an inpatient and outpatient basis.

Objective

To evaluate whether the outpatient use of mifepristone for cervical ripening before IOL at term is as efficient and safe as in inpatients.

Study design

This open-label, prospective, two-arm, non-inferiority randomised controlled trial (ISRCTN26164110) with a 1:1 allocation ratio was conducted in a single tertiary referral hospital. Overall, 322 pregnant women (gestational age: 39-41 weeks; Bishop score < 6, intact membranes, no contraindications for vaginal delivery, and no contraindications for IOL) were included and randomised:162 to the outpatient group and 160 to the inpatient group for cervical ripening with mifepristone. Analyses were performed based on the intention-to-treat principle.

Results

In 16 % and 17 % of the cases, labour began spontaneously within 24-36 h after taking mifepristone tablets. The additional use of prostaglandin E2 or a balloon for cervical ripening occurred equally often in the compared groups. Oxytocin was used more frequently to induce labour in the inpatient group (P = 0.035). There was no difference in the length of the interval from the onset of cervical ripening to the onset of labour between the groups (38.6 vs. 38.8 h, P = 0.900). The failed induction rate was 1.85 % vs. 0.63 % (P = 0.346).Regional analgesia (P = 0.011) and abnormal foetal heart rate patterns (P = 0.027) were more common in the inpatient group. In the outpatient mifepristone preinduction group, the average time interval from hospitalisation to discharge was 25 h shorter (P < 0.001). No statistically significant differences were observed between the groups in terms of the rates of adverse side effects or perinatal outcomes.

Conclusion

Outpatient cervical ripening with mifepristone reduced the hospital stay duration compared to inpatient ripening, with no difference in efficacy in terms of improvement in the Bishop score, frequency of additional induction method usage, interval from start of preinduction to onset of labour, and labour duration.No differences in the delivery methods, failure rates, or perinatal outcomes were observed. The frequency of adverse effects was low and not related to the setting of the preinduction site. Cervical ripening with mifepristone can be performed on an outpatient basis, because it is as effective and safe as inpatient ripening.

Clinical Update on Uses for Mifepristone in Obstetrics and Gynecology

IMPORTANCE

Mifepristone (RU-486) is a selective progesterone receptor modulator that has antagonist properties on the uterus and cervix. Mifepristone is an effective abortifacient, prompting limitations on its use in many countries. Mifepristone has many uses outside of induced abortion, but these are less well known and underutilized by clinicians because of challenges in accessing and prescribing this medication.

OBJECTIVES

To provide clinicians with a history of the development of mifepristone and mechanism of action and safety profile, as well as detail current research on uses of mifepristone in both obstetrics and gynecology.

EVIDENCE ACQUISITION

A PubMed search of mifepristone and gynecologic and obstetric conditions was conducted between January 2018 and December 2021. Other resources were also searched, including guidelines from the American College of Obstetricians and Gynecologists and the Society of Family Planning.

RESULTS

Mifepristone is approved by the Food and Drug Administration for first-trimester medication abortion but has other off-label uses in both obstetrics and gynecology. Obstetric uses that have been investigated include management of early pregnancy loss, intrauterine fetal demise, treatment of ectopic pregnancy, and labor induction. Gynecologic uses that have been investigated include contraception, treatment of abnormal uterine bleeding, and as an adjunct in treatment of gynecologic cancers.

CONCLUSIONS AND RELEVANCE

Mifepristone is a safe and effective medication both for its approved use in first-trimester medication abortion and other off-label uses. Because of its primary use as an abortifacient, mifepristone is underutilized by clinicians. Providers should consider mifepristone for other indications as clinically appropriate.

Sonoelastography for the comparative assessment of cervical maturation after different approaches to cervical preparation ahead of labor induction

Aim: To compare the efficacy of different approaches to cervical preparation to labor induction using the ultrasound cervical elastography.Materials and methods: This prospective open-label study included 200 pregnant women aged between 23 and 38 years eligible for labor pre-induction. Patients were divided into four groups (n = 50 per group). In Group I, four osmotic Dilapan-S cervical dilators combined with two doses of oral mifepristone (200 mg each) 24 h apart were used. The dilators were inserted for up to 12 h. In Group II, only the Dipalan-S dilators were used. In Group III, a Foley catheter was positioned intracervically for 12 h. In Group IV, we used two doses of intracervical prostaglandin E₂ gel (0.5 mg each) 6 h apart. Cervical maturation was assessed using the Bishop scoring system and the ultrasound cervicometry with the color mapping and calculation of SR ratio. At baseline, all participants were also divided into three subgroups depending on the Bishop score before the pre-induction. Subgroup А (n = 66) included patients with the Bishop score between 0‒2 points, subgroup B (n = 69) between 3-4 points, and subgroup С (n = 65) between 4-6 points.Results: Our study showed that the efficacy of Dilapan-S combined with mifepristone for cervical preparation to labor induction was higher than Dilapan-S, Foley catheter and intracervical prostaglandin E₂ gel. In this group, the Bishop score after the pre-induction was the highest (11.4 (0.21) points versus 10.2 (0.2), 9.4 (0.3) и 9.67 (0.25) in Groups II, III and IV respectively (p < .05 for all). The lowest SR values were also observed among the patients receiving the combination of Dilapan-S and mifepristone: 1.23 (0.04) versus 1.63 (0.07), 1.7 (0.08) and 1.83 (0.1) in Groups II, III and IV respectively (p < .05 for all). The sonoelastographic SR values in subgroups B and C were statistically lower compared with subgroup A across all groups studied. Ultrasound elastography of the cervix allowed to perform a more objective assessment of cervical maturation compared with the Bishop scoring.Conclusion: Dilapan-S combined with mifepristone had higher efficacy for cervical preparation to labor induction compared with other approaches investigated.