Mechanical methods for induction of labour

Preinduction cervical ripening in an outpatient setting: a prospective pilot study of a synthetic osmotic dilator compared with a double-balloon catheter

OBJECTIVES

To compare the effectiveness, safety and patient satisfaction of a double balloon catheter (DB) with a synthetic osmotic cervical dilator (OD) for pre-induction cervical ripening in an outpatient setting.

METHODS

This is a prospective, dual-center pilot study including 94 patients with an unripe cervix (Bishop Score <6) near term; 50 patients received the DB and 44 patients the OD. The primary outcomes were the difference in Bishop Score (BS) and cervical shortening. Pain perception at insertion and during the cervical ripening period was evaluated by a visual analogue scale and patient satisfaction by a predefined questionnaire.

RESULTS

The use of DB was associated with a significantly higher increase in BS (median 3) compared to OD (median 2; p=0.002) and resulted in significantly greater cervical shortening (median -14 mm vs. -9 mm; p=0.003). There were no serious adverse events at placement of devices or during the cervical ripening. There were no significant differences in perinatal outcomes. Pain perception during cervical ripening was significantly higher (p<0.001), and patient satisfaction regarding sleep, relaxing time and performing desired daily activities were significantly lower in patients with DB compared to patients with OD (p<0.001).

CONCLUSIONS

DB was superior to OD regarding cervical ripening based on BS and on sonographic measurement of the cervical length. Patients with OD experienced less pain during cervical ripening and were more satisfied with the method compared to patients with DB.

The hormonal control of parturition

Parturition is a complex physiological process that must occur in a reliable manner and at an appropriate gestation stage to ensure a healthy newborn and mother. To this end, hormones that affect the function of the gravid uterus, especially progesterone (P4), 17β-estradiol (E2), oxytocin (OT), and prostaglandins (PGs), play pivotal roles. P4 via the nuclear P4 receptor (PR) promotes uterine quiescence and for most of pregnancy exerts a dominant block to labor. Loss of the P4 block to parturition in association with a gain in prolabor actions of E2 are key transitions in the hormonal cascade leading to parturition. P4 withdrawal can occur through various mechanisms depending on species and physiological context. Parturition in most species involves inflammation within the uterine tissues and especially at the maternal-fetal interface. Local PGs and other inflammatory mediators may initiate parturition by inducing P4 withdrawal. Withdrawal of the P4 block is coordinated with increased E2 actions to enhance uterotonic signals mediated by OT and PGs to promote uterine contractions, cervix softening, and membrane rupture, i.e., labor. This review examines recent advances in research to understand the hormonal control of parturition, with focus on the roles of P4, E2, PGs, OT, inflammatory cytokines, and placental peptide hormones together with evolutionary biology of and implications for clinical management of human parturition.

Effect of cervical Bishop score on induction of labor at term in primiparas using Foley catheter balloon: a retrospective study

BACKGROUND

Previous studies had found that the mechanical methods were as effective as pharmacological methods in achieving vaginal delivery. However, whether balloon catheter induction is suitable for women with severe cervical immaturity and whether it will increase the related risks still need to be further explored.

RESEARCH AIM

To evaluate the efficacy and safety of Foley catheter balloon for labor induction at term in primiparas with different cervical scores.

METHODS

A total of 688 primiparas who received cervical ripening with a Foley catheter balloon were recruited in this study. They were divided into 2 groups: Group 1 (Bishop score ≤ 3) and Group 2 (3 < Bishop score < 7). Detailed medical data before and after using of balloon were faithfully recorded.

RESULTS

The cervical Bishop scores of the two groups after catheter placement were all significantly higher than those before (Group 1: 5.49 ± 1.31 VS 2.83 ± 0.39, P<0.05; Group 2: 6.09 ± 1.00 VS 4.45 ± 0.59, P<0.05). The success rate of labor induction in group 2 was higher than that in group 1 (P<0.05). The incidence of intrauterine infection in Group 1 was higher than that in Group 2 (18.3% VS 11.3%, P<0.05).

CONCLUSION

The success rates of induction of labor by Foley catheter balloon were different in primiparas with different cervical conditions, the failure rate of induction of labor and the incidence of intrauterine infection were higher in primiparas with severe cervical immaturity.

Interval between balloon removal and oxytocin administration in cervical ripening with double-balloon in singleton pregnancies: An observational study

OBJECTIVE

To analyze the influence of the resting interval after removal of a double-balloon for cervical ripening and oxytocin administration on the time to onset of active labor in singleton pregnancies.

METHODS

A retrospective cohort study of women who required a cervical ripening with double-balloon was conducted between January 2019 and December 2022. We collected data for cervical ripening balloon insertion and removal, oxytocin administration, suspicious or pathological cardiotocographic trace, mode of delivery, maternal and neonatal complications, neonatal outcomes. Proportional hazards model comparing resting interval between double-balloon cervical ripening removal and oxytocin administration.

RESULTS

A total of 403 singleton pregnancies were recruited and 213 pregnant women experienced a rest of 12 h between cervical balloon removal and oxytocin administration (resting group). Oxytocin was administered immediately after balloon removal in 190 women (non-resting group). Median insertion-to-active labor interval and insertion-to-delivery interval were significantly shorter in the non-resting group: 18.5 versus 24.0 h, HR 2.59 (CI 95%: 1.97-3.41) and 24.0 versus 29.0 h, HR 2.38 (CI 95%: 1.85-3.05) respectively. Bishop score change and mode of delivery between were similar in both groups. No differences in maternal nor neonatal complications between both groups were found.

CONCLUSIONS

Oxytocin administration immediately after removal of a double-balloon for cervical ripening compared with 12 h delayed interval resulted in a shortened time from insertion to active labor onset and to delivery interval without increasing maternal or neonatal adverse outcomes.

Comparison of pre and post Foley catheter Bishop's Score: A retrospective record review at Aga Khan University Hospital Karachi, Pakistan

Objective

To compare pre and post Foley's catheter Bishop Score during labour induction.

Methods

This study was a retrospective study conducted at the Aga Khan University Hospital Karachi, Pakistan after approval from ethical review board. All women who underwent induction of labour with Foley's Catheter at gestation of 37 weeks or more from September 2014-October 2015 were included. Data was entered and analyzed in Statistical Package for Social Sciences (SPSS) version 19.0. The comparison between pre and post Foley's catheter Bishop Score during labour induction will be calculated by Wilcoxon sign test.

Results

There were 981 cases of inductions of labour, 749 (76.3%) received Foley's catheter, in combination with prostaglandins and oxytocin. About 68% were vaginal deliveries while 32% underwent C-section. Two third of women had bishop <4. Overall, Bishop score improved significantly in all patients with the catheter however, maximum benefit was seen in patients where the catheter was placed for 10-12 hours.

Conclusion

Foley's is the better and safer option. In view of our results, It has been recommended to keep the Foley's for 10-12 hours to get significant improvement in bishop score.

Clinical analysis of prophylactic uterine artery embolization combined with double balloon catheter for second-trimester pregnancy termination in cases of complete placenta previa: A retrospective study

Complete placenta previa often causes significant bleeding in a short period during second-trimester pregnancy termination. This can destabilize the mother's circulation, threatening her life. Furthermore, the condition is complicated by an immature cervix, making it a challenging clinical problem. The aim of this study was to investigate the effect of prophylactic uterine artery embolization (UAE) combined with double balloon catheter (DBC) deal with those cases. A total of 7 patients who underwent pregnancy termination in the second-trimester in Maternal and Child Health Hospital of Hubei Province between March 1st, 2021 and August 31st, 2023 were retrospectively analyzed in this study. All patients were diagnosed with complete placenta previa status and placenta accreta spectrum, and were treated with prophylactic UAE combined with DBC, and/or dilation and evacuation. All the patients received mifepristone, and 5 of them underwent medical termination with ethacridine lactate. Following prophylactic UAE combined with DBC, 6 patients underwent dilation and evacuation, which was monitored by ultrasound. And one patient experienced natural delivery of their fetus and placenta. Only one patient (patient 3) developed an intrapartum fever after prolonged duration of 18 hours from ethacridine to UAE and 56 hours from UAE to DBC. The amount of intrapartum hemorrhage ranged from 20 mL to 300 mL. The combined therapy of prophylactic UAE and DBC is a preferred option for patients with complete placenta previa undergoing second-trimester pregnancy termination. The use of dilation and evacuation may depend on the cervical condition, bleeding, or infection.