Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term

Inhibition of interleukin-1 signaling protects against Group B streptococcus-induced preterm birth and fetal loss in mice

Group B streptococcus is a common microbial agent associated with spontaneous preterm birth and fetal inflammatory response syndrome. In this study, we evaluated the utility of rytvela, a novel peptide antagonist of the interleukin-1 receptor, to suppress inflammatory activation, prolong gestation and improve neonatal outcomes induced in mice by Group B streptococcus. Pregnant mice were administered rytvela or PBS on gestation day 16.5, immediately prior and following surgical administration of heat-killed Group B streptococcus (hkGBS) or PBS into the uterine cavity. Treatment with rytvela prevented preterm delivery and alleviated fetal demise in utero and in the perinatal phase elicited by hkGBS. Compared to pups exposed to hkGBS alone, pups of dams co-administered rytvela exhibited substantially improved survival and growth through to weaning. Analysis by qPCR showed expression of inflammatory cytokine genes Il1b, Il6, Tnf, and Ifng in uterine tissues, and Il1b, Il6, and Tnf in fetal membranes, were stimulated by hkGBS and this increase was suppressed by co-administration of rytvela. Premature induction of uterine activation gene Ptgs2 in the myometrium was also attenuated by rytvela treatment. These data show that activation of IL1-mediated signaling in response to Group B streptococcus triggers an inflammatory cascade that causes preterm parturition and fetal inflammatory injury, and that rytvela can suppress inflammatory mediators to substantially improve pregnancy and fetal outcomes. Our findings add to accumulating evidence supporting clinical investigation of rytvela for fetal protection and delaying preterm birth.

PGF2α induces a pro-labour phenotypical switch in human myometrial cells that can be inhibited with PGF2α receptor antagonists

Preterm birth is the leading cause of infant morbidity and mortality. There has been an interest in developing prostaglandin F2α (PGF2α) antagonists as a new treatment for preterm birth, although much of the rationale for their use is based on studies in rodents where PGF2α initiates labour by regressing the corpus luteum and reducing systemic progesterone concentrations. How PGF2α antagonism would act in humans who do not have a fall in systemic progesterone remains unclear. One possibility, in addition to an acute stimulation of contractions, is a direct alteration of the myometrial smooth muscle cell state towards a pro-labour phenotype. In this study, we developed an immortalised myometrial cell line, MYLA, derived from myometrial tissue obtained from a pregnant, non-labouring patient, as well as a novel class of PGF2α receptor (FP) antagonist. We verified the functionality of the cell line by stimulation with PGF2α, resulting in Gαq-specific coupling and Ca2+ release, which were inhibited by FP antagonism. Compared to four published FP receptor antagonists, the novel FP antagonist N582707 was the most potent compound [Fmax 7.67 ± 0.63 (IC50 21.26 nM), AUC 7.30 ± 0.32 (IC50 50.43 nM), and frequency of Ca2+ oscillations 7.66 ± 0.41 (IC50 22.15 nM)]. RNA-sequencing of the MYLA cell line at 1, 3, 6, 12, 24, and 48 h post PGF2α treatment revealed a transforming phenotype from a fibroblastic to smooth muscle mRNA profile. PGF2α treatment increased the expression of MYLK, CALD1, and CNN1 as well as the pro-labour genes OXTR, IL6, and IL11, which were inhibited by FP antagonism. Concomitant with the inhibition of a smooth muscle, pro-labour transition, FP antagonism increased the expression of the fibroblast marker genes DCN, FBLN1, and PDGFRA. Our findings suggest that in addition to the well-described acute contractile effect, PGF2α transforms myometrial smooth muscle cells from a myofibroblast to a smooth muscle, pro-labour-like state and that the novel compound N582707 has the potential for prophylactic use in preterm labour management beyond its use as an acute tocolytic drug.

A novel method for assessing the condition of the cervix before labor induction: Cervical length/thickness ratio

Background/Aim: Due to the increasing cesarean rates globally, new methods for supporting vaginal delivery and induction of successful vaginal delivery are still being developed. We aimed to obtain an easy-to-use method that can predict the effectiveness of cervical ripening agents before labor induction. So, we presented the effects on labor by measuring the thickness of the cervix and the cervical length/thickness ratio ultrasonographically. Methods: In this prospective cohort study, we evaluated 183 pregnant between 37 and 41 weeks of gestational age and will apply vaginal delivery induction. Before oxytocin induction, we applied 10 mg dinoprostone vaginally to women whose cervix was stiff. We started labor induction with oxytocin when regular uterine contractions or dilatation occurred. We used the Bishop Scoring System for favorable cervix defining. Then, we compared the groups with successful and unsuccessful cervical ripening regarding cervical length and thickness parameters. Results: The mean cervical thickness of the pregnant women with successful cervical ripening was 34.5 (7.5) mm before treatment, while the mean values of the unsuccessful group were 29.2 (9.1) mm (P < 0.001). The cervical length did not differ between the two groups (31.6 [8.2] vs. 32.5 [6.8], P = 0.44), while the cervical length/thickness ratio was lower in the group with successful ripening (0.9 [0.38–2], P < 0.001). Cervical length/thickness ratio was the highest predictor of the favorable cervix with dinoprostone. Each 1 unit decrease in the length/thickness ratio of the cervix increases the preparation of the cervix for induction by 0.25 times (P = 0.04). A successful response to dinoprostone can be obtained if the cervical length/thickness ratio is <1.06 mm (P < 0.001). Conclusion: In conclusion, assessing the cervix’s condition before labor induction by measuring the cervical length/thickness ratio may be a good predictor of cervical ripening activity.

Oral misoprostol, low dose vaginal misoprostol, and vaginal dinoprostone for labor induction: Randomized controlled trial

OBJECTIVE

To compare effectiveness and safety of oral misoprostol (50 μg every four hours as needed), low dose vaginal misoprostol (25 to 50 μg every six hours as needed), and our established dinoprostone vaginal gel (one to two mg every six hours as needed) induction.

MATERIALS AND METHODS

Consenting women with a live term single cephalic fetus for indicated labor induction were randomized (3N = 511). Prior uterine surgery or non-reassuring fetal surveillance were exclusions. Concealed computer generated randomization was stratified and blocked. Newborns were assessed by a team unaware of group assignment. The primary outcome was time from induction at randomization to vaginal birth for initial parametric analysis. Sample size was based on mean difference of 240 minutes with α2 = 0.05 and power 95%. Non-parametric analysis was also pre-specified ranking cesareans as longest vaginal births.

RESULTS

Enrollment was from April 1999 to December 2000. Demographics were similar across groups. Analysis was by intent to treat, with no loss to follow up. Mean time (±SD) to vaginal birth was 1356 (±1033) minutes for oral misoprostol, 1530 (±3249) minutes for vaginal misoprostol, and 1208 (±613) minutes for vaginal dinoprostone (P = 0.46, ANOVA). Median times to vaginal birth were 1571, 1339, and 1451 minutes respectively (P = 0.46, Kruskal-Wallis). Vaginal births occurred within 24 hours in 44.9, 53.5 and 47.7% respectively (P = 0.27, χ2). There were no significant differences in Kaplan Meier survival analyses, cesareans, adverse effects, or maternal satisfaction. The newborn who met birth asphyxia criteria received vaginal misoprostol, as did. all three other newborns with cord artery pH<7.0 (P = 0.04, Fisher Exact).

CONCLUSION

There was no significant difference in effectiveness of the three groups. Profound newborn acidemia, though infrequent, occurred only with low dose vaginal misoprostol.

Is there an interest in repeating the vaginal administration of dinoprostone (Propess®), to promote induction of labor of pregnant women at term? (RE-DINO): study protocol for a randomized controlled trial

BACKGROUND

Labor is induced in over 20% of women in France. Prostaglandins, especially intravaginal dinoprostone (Propess®), are widely used to initiate cervical ripening. If labor does not start within 24 h, there is uncertainty about whether to administer a second dinoprostone pessary or to use oxytocin to induce labor in order to achieve a vaginal delivery.

METHODS

RE-DINO is a prospective, open-label, multicenter, randomized superiority trial with two parallel arms running in six French hospitals. A total of 360 patients ≥ 18 years of age at > 37 weeks of gestation who exhibit unfavorable cervical conditions (Bishop score < 6) 24 h after placement of the first Propess®, with fetuses in cephalic presentation, will be included. Patients with premature membrane rupture, uterine scars, or multiple pregnancies will be excluded. Our principal objective is to determine whether placement of a second Propess® (followed by oxytocin [Syntocinon®], if necessary) in women for whom the first Propess® failed to induce cervical ripening increases the vaginal delivery rate compared to direct oxytocin injection. The vaginal delivery rate is therefore the primary outcome. The secondary outcomes are the induction failure rates and maternofetal morbidity and mortality.

DISCUSSION

This study may help in determining the optimal way to induce labor after failure of a first Propess®, an unresolved problem to date. This trial explores the effectiveness and safety of placing a second Propess® and may contribute to development of an obstetric consensus.

TRIAL REGISTRATION

Registered on 2 September 2016 at clinicaltrials.gov (identification number NCT02888041).

The Modifying Role of Socioeconomic Position and Greenness on the Short-Term Effect of Heat and Air Pollution on Preterm Births in Rome, 2001-2013

Urban green spaces have been associated with health benefits, but few studies have evaluated the role of greenness on pregnancy outcomes. We examined how the association between short-term exposure to heat and air pollution on the probability of preterm delivery is affected by the spatial variation of socioeconomic position (SEP) and greenness. We analyzed a cohort of newborns in Rome, from April to October of 2001-2013, defining preterm as births between the 22nd and the 36th week of gestation. We used a time series approach, with maximum apparent temperature (MAT), PM10, NO2, and O3 as exposure variables. As greenness indicators, we considered maternal residential proximity to green spaces and the Normalized Difference Vegetation Index (NDVI) within a 100 m buffer around each woman's residential address. We enrolled 56,576 newborns (5.1% preterm). The effect of a 1 °C increase in temperature on the daily number of preterm births was higher in women with low SEP (+2.49% (90% CI: 1.29-3.71)) and among those living within 100 m from green spaces (+3.33% (90% CI: 1.82-4.87)). No effect modification was observed for NDVI or PM10. SEP was an important effect modifier of the heat-preterm birth relationship. The role of greenness in modifying this association between heat and preterm delivery should be further investigated.

Does an elective induction policy negatively impact on vaginal delivery rates? A 30-month review of an elective induction policy

BACKGROUND

The rate of induction of labour varies across Health Service Executive hospital regions in Ireland averaging at 23.3 per 100 deliveries in 2005-2009. The increasing rate of elective induction of labour in Ireland calls for more studies looking into associated maternal and/or neonatal outcomes.

STUDY AIM

The aim of this study is to show that an elective induction policy with management by a sole consultant obstetrician can decrease caesarean section rates as well as positively impact maternal and neonatal complications.

METHODS

We conducted a retrospective review of women attending a named obstetrician over a 1-year period. In total, 22 variables were collected, including basic patient demographics, mode of onset of labour, method of induction, mode of delivery, length of labour and neonatal outcomes.

RESULTS

In total, 583 patients were identified in the study period. One hundred twenty-six (21.6%) patients presented with a spontaneous onset of labour, and 405 (69.4%) of patients had an induction of labour. Relative risk of having an emergency caesarean section, if labour is induced, is 1.42 (95% CI 0.64 to 3.14), and no statistical significance was demonstrated (p = 0.38). There was a statistically significant difference in operative vaginal delivery versus standard vaginal delivery relative risk between women ≥ 35-year-old and < 35-year-old groups, 0.47 (95% CI 0.39-0.57), p < 0.0001.

CONCLUSION

Elective induction of labour is not associated with an increased risk of caesarean section or operative vaginal delivery in patients less than 35 years of age. This shows that elective induction is an appropriate intervention in selected scenarios without affecting mode of delivery.

Acupuncture in Postdate Pregnancy Management

OBJECTIVES

Pharmacological labor induction is obtained through prostaglandins application and/or oxytocin infusion; however, the use seems to be related to fetal and maternal side effects. Traditional Chinese Medicine advocates the use of acupuncture to soften the cervix and induce uterine contractions. at which presented for The primary outcome was the rate of women admitted for labour induction in case of prolonged pregnancy at 41 + 5 weeks, and the secondary outcome was the rate of induction planning for other indications.

METHODS

After obtaining informed consent, 375 undelivered women after 40 + 2 gestational age were enrolled for the study: 112 women received acupuncture and 263, routine care. Acupuncture was applied every odd day starting from 40 + 2 weeks up to 41 + 4 weeks. Women allocated to the control group received standard care. At 41 + 5 weeks, a pharmacological induction was planned.

RESULTS

The rate of labor induction significantly differed between acupuncture and observation groups (19.6% vs. 38%; p < 0.01); in particular, women receiving acupuncture showed a lower rate of induction, indicating prolonged pregnancy (5.3% vs. 10.1%; p < 0.01). As far as the pharmacological device is concerned, no differences were observed with regard to the prostaglandins use, whereas oxytocin infusion rate was lower in the acupuncture group than in the observation group.

CONCLUSIONS

The present study suggested that acupuncture applied at term of pregnancy seems to be effective in reducing the rate of labor induction which is performed for prolonged pregnancy at 41 + 5 weeks. Moreover, acupuncture also seems to be able to reduce oxytocin use; such a "saving" effect could play a role in childhood, considering that a recent study underlined the adverse effect of oxytocin on birth outcomes.

Which method is best for the induction of labour? A systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

More than 150,000 pregnant women in England and Wales have their labour induced each year. Multiple pharmacological, mechanical and complementary methods are available to induce labour.

OBJECTIVE

To assess the relative effectiveness, safety and cost-effectiveness of labour induction methods and, data permitting, effects in different clinical subgroups.

METHODS

We carried out a systematic review using Cochrane methods. The Cochrane Pregnancy and Childbirth Group's Trials Register was searched (March 2014). This contains over 22,000 reports of controlled trials (published from 1923 onwards) retrieved from weekly searches of OVID MEDLINE (1966 to current); Cochrane Central Register of Controlled Trials (The Cochrane Library); EMBASE (1982 to current); Cumulative Index to Nursing and Allied Health Literature (1984 to current); ClinicalTrials.gov; the World Health Organization International Clinical Trials Registry Portal; and hand-searching of relevant conference proceedings and journals. We included randomised controlled trials examining interventions to induce labour compared with placebo, no treatment or other interventions in women eligible for third-trimester induction. We included outcomes relating to efficacy, safety and acceptability to women. In addition, for the economic analysis we searched the Database of Abstracts of Reviews of Effects, and Economic Evaluations Databases, NHS Economic Evaluation Database and the Health Technology Assessment database. We carried out a network meta-analysis (NMA) using all of the available evidence, both direct and indirect, to produce estimates of the relative effects of each treatment compared with others in a network. We developed a de novo decision tree model to estimate the cost-effectiveness of various methods. The costs included were the intervention and other hospital costs incurred (price year 2012-13). We reviewed the literature to identify preference-based utilities for the health-related outcomes in the model. We calculated incremental cost-effectiveness ratios, expected costs, utilities and net benefit. We represent uncertainty in the optimal intervention using cost-effectiveness acceptability curves.

RESULTS

We identified 1190 studies; 611 were eligible for inclusion. The interventions most likely to achieve vaginal delivery (VD) within 24 hours were intravenous oxytocin with amniotomy [posterior rank 2; 95% credible intervals (CrIs) 1 to 9] and higher-dose (≥ 50 µg) vaginal misoprostol (rank 3; 95% CrI 1 to 6). Compared with placebo, several treatments reduced the odds of caesarean section, but we observed considerable uncertainty in treatment rankings. For uterine hyperstimulation, double-balloon catheter had the highest probability of being among the best three treatments, whereas vaginal misoprostol (≥ 50 µg) was most likely to increase the odds of excessive uterine activity. For other safety outcomes there were insufficient data or there was too much uncertainty to identify which treatments performed 'best'. Few studies collected information on women's views. Owing to incomplete reporting of the VD within 24 hours outcome, the cost-effectiveness analysis could compare only 20 interventions. The analysis suggested that most interventions have similar utility and differ mainly in cost. With a caveat of considerable uncertainty, titrated (low-dose) misoprostol solution and buccal/sublingual misoprostol had the highest likelihood of being cost-effective.

LIMITATIONS

There was considerable uncertainty in findings and there were insufficient data for some planned subgroup analyses.

CONCLUSIONS

Overall, misoprostol and oxytocin with amniotomy (for women with favourable cervix) is more successful than other agents in achieving VD within 24 hours. The ranking according to safety of different methods was less clear. The cost-effectiveness analysis suggested that titrated (low-dose) oral misoprostol solution resulted in the highest utility, whereas buccal/sublingual misoprostol had the lowest cost. There was a high degree of uncertainty as to the most cost-effective intervention.

FUTURE WORK

Future trials should be powered to detect a method that is more cost-effective than misoprostol solution and report outcomes included in this NMA.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005116.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Acupuncture or acupressure for induction of labour

BACKGROUND

This is one of a series of reviews of methods of cervical ripening and labour induction. The use of complementary therapies is increasing. Women may look to complementary therapies during pregnancy and childbirth to be used alongside conventional medical practice. Acupuncture involves the insertion of very fine needles into specific points of the body. Acupressure is using the thumbs or fingers to apply pressure to specific points. The limited observational studies to date suggest acupuncture for induction of labour has no known adverse effects to the fetus, and may be effective. However, the evidence regarding the clinical effectiveness of this technique is limited.

OBJECTIVES

To determine, from the best available evidence, the effectiveness and safety of acupuncture and acupressure for third trimester cervical ripening or induction of labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 November 2016), PubMed (1966 to 25 November 2016), ProQuest Dissertations & Theses (25 November 2016), CINAHL (25 November 2016), Embase (25 November 2016), the WHO International Clinical Trials Registry Portal (ICTRP) (3 October 2016), and bibliographies of relevant papers.

SELECTION CRITERIA

Randomised controlled trials comparing acupuncture or acupressure, used for third trimester cervical ripening or labour induction, with placebo/no treatment or other methods on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy. The quality of the evidence was assessed using GRADE.

MAIN RESULTS

This updated review includes 22 trials, reporting on 3456 women. The trials using manual or electro-acupuncture were compared with usual care (eight trials, 760 women), sweeping of membranes (one trial, 207 women), or sham controls (seven trials, 729 women). Trials using acupressure were compared with usual care (two trials, 151 women) or sham controls (two trials, 239 women). Many studies had a moderate risk of bias.Overall, few trials reported on primary outcomes. No trial reported vaginal delivery not achieved within 24 hours and uterine hyperstimulation with fetal heart rate (FHR) changes. Serious maternal and neonatal death or morbidity were only reported under acupuncture versus sham control. Acupuncture versus sham control There was no clear difference in caesarean sections between groups (average risk ratio (RR) 0.80, 95% confidence interval (CI) 0.56 to 1.15, eight trials, 789 women; high-quality evidence). There were no reports of maternal death or perinatal death in the one trial that reported this outcome. There was evidence of a benefit from acupuncture in improving cervical readiness for labour (mean difference (MD) 0.40, 95% CI 0.11 to 0.69, one trial, 125 women), as measured by cervical maturity within 24 hours using Bishop's score. There was no evidence of a difference between groups for oxytocin augmentation, epidural analgesia, instrumental vaginal birth, meconium-stained liquor, Apgar score < 7 at five minutes, neonatal intensive care admission, maternal infection, postpartum bleeding greater than 500 mL, time from the trial to time of birth, use of induction methods, length of labour, and spontaneous vaginal birth. Acupuncture versus usual care There was no clear difference in caesarean sections between groups (average RR 0.77, 95% CI 0.51 to 1.17, eight trials, 760 women; low-quality evidence). There was an increase in cervical maturation for the acupuncture (electro) group compared with control (MD 1.30, 95% CI 0.11 to 2.49, one trial, 67 women) and a shorter length of labour (minutes) in the usual care group compared to electro-acupuncture (MD 124.00, 95% CI 37.39 to 210.61, one trial, 67 women).There appeared be a differential effect according to type of acupuncture based on subgroup analysis. Electro-acupuncture appeared to have more of an effect than manual acupuncture for the outcomes caesarean section (CS), and instrumental vaginal and spontaneous vaginal birth. It decreased the rate of CS (average RR 0.54, 95% CI 0.37 to 0.80, 3 trials, 327 women), increased the rate of instrumental vaginal birth (average RR 2.30, 95%CI 1.15 to 4.60, two trials, 271 women), and increased the rate of spontaneous vaginal birth (average RR 2.06, 95% CI 1.20 to 3.56, one trial, 72 women). However, subgroup analyses are observational in nature and so results should be interpreted with caution.There were no clear differences between groups for other outcomes: oxytocin augmentation, use of epidural analgesia, Apgar score < 7 at 5 minutes, neonatal intensive care admission, maternal infection, perineal tear, fetal infection, maternal satisfaction, use of other induction methods, and postpartum bleeding greater than 500 mL. Acupuncture versus sweeping if fetal membranes One trial of acupuncture versus sweeping of fetal membranes showed no clear differences between groups in caesarean sections (RR 0.64, 95% CI 0.34 to 1.22, one trial, 207 women, moderate-quality evidence), need for augmentation, epidural analgesia, instrumental vaginal birth, Apgar score < 7 at 5 minutes, neonatal intensive care admission, and postpartum bleeding greater than 500 mL. Acupressure versus sham control There was no evidence of benefit from acupressure in reducing caesarean sections compared to control (RR, 0.94, 95% CI 0.68 to 1.30, two trials, 239 women, moderate-quality evidence). There was no evidence of a clear benefit in reduced oxytocin augmentation, instrumental vaginal birth, meconium-stained liquor, time from trial intervention to birth of the baby, and spontaneous vaginal birth. Acupressure versus usual care There was no evidence of benefit from acupressure in reducing caesarean sections compared to usual care (RR 1.02, 95% CI 0.68 to 1.53, two trials, 151 women, moderate-quality evidence). There was no evidence of a clear benefit in reduced epidural analgesia, Apgar score < 7 at 5 minutes, admission to neonatal intensive care, time from trial intervention to birth of the baby, use of other induction methods, and spontaneous vaginal birth.

AUTHORS' CONCLUSIONS

Overall, there was no clear benefit from acupuncture or acupressure in reducing caesarean section rate. The quality of the evidence varied between low to high. Few trials reported on neonatal morbidity or maternal mortality outcomes. Acupuncture showed some benefit in improving cervical maturity, however, more well-designed trials are needed. Future trials could include clinically relevant safety outcomes.

Mechanical cervicAl ripeninG for women with PrOlongedPregnancies (MAGPOP): protocol for a randomised controlled trial of a silicone double balloon catheter versus the Propess system for the slow release of dinoprostone for cervical ripening of prolonged pregnancies

INTRODUCTION

Induction of labour for prolonged pregnancies (PP) when the cervix is unfavourable is a challenging situation. Cervical ripening by pharmacological or mechanical techniques before oxytocin administration is used to increase the likelihood of vaginal delivery. Both techniques are equally effective in achieving vaginal delivery but excessive uterine activity, which induces fetal heart rate (FHR) anomalies, is more frequent after the pharmacological intervention. We hypothesised that mechanical cervical ripening could reduce the caesarean rate for non-reassuring FHR especially in PP where fetuses are already susceptible to this.

METHODS AND ANALYSIS

A multicentre, superiority, open-label, parallel-group, randomised controlled trial that aims to compare cervical ripening with a mechanical device (Cervical Ripening Balloon, Cook-Medical Europe, Ireland) inserted in standardised manner for 24 hours to pharmacological cervical ripening (Propess system for slow release system of 10 mg of dinoprostone, Ferring SAS, France) before oxytocin administration. Women (n=1220) will be randomised in a 1:1 ratio in 15 French units. Participants will be women with a singleton pregnancy, a vertex presentation, a term ≥41+0 and≤42+0 week's gestation, and for whom induction of labour is planned. Women with a Bishop score ≥6, a prior caesarean delivery, premature rupture of membranes or with any contraindication for vaginal delivery will be excluded. The primary endpoint is the caesarean rate for non-reassuring FHR. Secondary outcomes are related to delivery and perinatal morbidity. As study investigators and patients cannot be masked to treatment assignment, to compensate for the absence of blinding, an independent endpoint adjudication committee, blinded to group allocation, will determine whether the caesarean for non-reassuring FHR was justified.

ETHICS AND DISSEMINATION

Written informed consent will be obtained from all participants. The Tours Research ethics committee has approved this study (2016-R23, 29 November 2016). Study findings will be submitted for publication and presented at relevant conferences.

TRIAL REGISTRATION NUMBER

NCT02907060; pre-results.

Outcome of misoprostol and oxytocin in induction of labour

BACKGROUND

Induction of labour is the process of initiating the labour by artificial means from 24 weeks of gestation. The main aim of this study is to find out the maternal and foetal outcomes after induction of labour with misoprostol and oxytocin beyond 37 weeks of gestation.

METHODS

This was a hospital-based observational study carried out at Paropakar Maternity and Women's Hospital, Nepal. Misoprostol of 25 µg was inserted in posterior fornix of vagina or oxytocin infusion was started from 2.5 units on whom induction was decided. Maternal and foetal/neonatal outcomes were observed. Collected data were analysed using SPSS and MS Excel.

RESULTS

General induction rate was found to be 7.2%. In this study, post-term pregnancy was found to be the most common reason for induction of labour. Analysis of onset of labour led to the finding that mean onset of labour was much rapid in oxytocin (6.6 h) than misoprostol (13.6 h). However, there is similarity in induction-delivery interval in both groups. Overall, the rate of normal delivery and caesarean section was found to be 64.9% and 33.2%, respectively. Similarly, normal delivery within 12 h was seen in 18.4% of the patients given with misoprostol and 43.5% in oxytocin group. Foetal distress was found as the most common reason for caesarean section. The overall occurrence of maternal complication was found to be similar in misoprostol and oxytocin groups, nausea/vomiting being the most common (36.7%) complication followed by fever (24.1%). Besides this, the most common neonatal complication found in overall cases was meconium stained liquor (49.2%).

CONCLUSION

It was found that misoprostol was used most frequently for induction of labour compared to oxytocin. The onset of labour was found to be rapid in oxytocin than misoprostol. However, the occurrence of side effects was found to be similar in both misoprostol and oxytocin groups.

Novel Toll-like receptor-4 antagonist (+)-naloxone protects mice from inflammation-induced preterm birth

Toll-like receptor 4 (TLR4) activation by bacterial infection, or by sterile inflammatory insult is a primary trigger of spontaneous preterm birth. Here we utilize mouse models to investigate the efficacy of a novel small molecule TLR4 antagonist, (+)-naloxone, the non-opioid isomer of the opioid receptor antagonist (−)-naloxone, in infection-associated preterm birth. Treatment with (+)-naloxone prevented preterm delivery and alleviated fetal demise in utero elicited by i.p. LPS administration in late gestation. A similar effect with protection from preterm birth and perinatal death, and partial correction of reduced birth weight and postnatal mortality, was conferred by (+)-naloxone administration after intrauterine administration of heat-killed E. coli. Local induction by E. coli of inflammatory cytokine genes Il1b, Il6, Tnf and Il10 in fetal membranes was suppressed by (+)-naloxone, and cytokine expression in the placenta, and uterine myometrium and decidua, was also attenuated. These data demonstrate that inhibition of TLR4 signaling with the novel TLR4 antagonist (+)-naloxone can suppress the inflammatory cascade of preterm parturition, to prevent preterm birth and perinatal death. Further studies are warranted to investigate the utility of small molecule inhibition of TLR-driven inflammation as a component of strategies for fetal protection and delaying preterm birth in the clinical setting.

Seasonal Pattern of Preterm Births in Korea for 2000-2012

The aim of this study was to investigate a seasonal pattern of preterm births in Korea. Data were obtained from the national birth registry of the Korean Statistics Office and included all births in Korea during the period 2000-2012 (n = 6,310,800). Delivery dates were grouped by month of the year or by season (winter [December, January, February], spring [March, April, May], summer [June, July, August], and autumn [September, October, November]). The seasonal patterns of prevalence of preterm births were assessed. The rates of preterm births at 37 weeks were highest twice a year (once in winter and again in summer). The rates of preterm births increased by 13.9% in summer and 7.5% in winter, respectively, than in spring (OR, 1.139; 95% CI, 1.127-1.152, and OR, 1.075; 95% 1.064-1.087, respectively) after controlling for age, the educational level of the parents, maternal parity, and neonatal gender. The pattern for spontaneous preterm births < 34 weeks was similar. In Korea, a seasonal pattern of preterm births was observed, with peak prevalence in summer and winter. A seasonal pattern of preterm births may provide new insights for the pathophysiology of preterm births.

Alterations in eicosanoid composition during embryonic development in the chorioallantoic membrane of the American alligator (Alligator mississippiensis) and domestic chicken (Gallus gallus)

Eicosanoids are signaling lipids known to regulate several physiological processes in the mammalian placenta, including the initiation of parturition. Though all amniotes construct similar extraembryonic membranes during development, the composition and function of eicosanoids in extraembryonic membranes of oviparous reptiles is largely unknown. The majority of effort placed in eicosanoid investigations is typically targeted toward defining the role of specific compounds in disease etiology; however, comprehensive characterization of several pathways in eicosanoid synthesis during development is also needed to better understand the complex role of these lipids in comparative species. To this end, we have examined the chorioallantoic membrane (CAM) of the American alligator (Alligator mississippiensis) and domestic chicken (Gallus gallus) during development. Previously, our lab has demonstrated that the CAM of several oviparous species shared conserved steroidogenic activity, a feature originally attributed to mammalian amniotes. To further explore this, we have developed a liquid chromatography/tandem mass spectrometry method that is used here to quantify multiple eicosanoids in the CAM of two oviparous species at different stages of development. We identified 18 eicosanoids in the alligator CAM; the cyclooxygenase (COX) pathway showed the largest increase from early development to later development in the alligator CAM. Similarly, the chicken CAM had an increase in COX products and COX activity, which supports the LC-MS/MS analyses. Jointly, our findings indicate that the CAM tissue of an oviparous species is capable of eicosanoid synthesis, which expands our knowledge of placental evolution and introduces the possibility of future comparative models of placental function.

Recombinant human relaxin versus placebo for cervical ripening: a double-blind randomised trial in pregnant women scheduled for induction of labour

BACKGROUND

Nonclinical studies indicate that the hormone relaxin is a good candidate for a safe cervical ripening agent that does not cause uterine contractions.

METHODS

This Phase II study (conducted November 2, 2005-October 20, 2006) was a randomised, double blind, placebo controlled trial testing 24-h intravenous infusion of serelaxin (recombinant human relaxin) or placebo for cervical ripening in 72 healthy, primiparous women. Eligible subjects had a singleton pregnancy ≥40 weeks, were planned for elective induction, had vertex presentation of the fetus, intact membranes and a Bishop score at screening ≤4. In Part A of the study, safety evaluation of three escalating doses of serelaxin (7.5, 25 or 75 μg/kg/day) or placebo was performed in 22 subjects admitted to the hospital 24 h prior to scheduled induction (n = 7, 4, 4, and 7 subjects, respectively). The highest safe dose from Part A and placebo were then tested in Part B for safety and cervical ripening (n = 25 subjects/arm). Planned randomisation ratio was of 4:2 (serelaxin:placebo) for each dose group in Part A and 1:1 for Part B. For analysis, subjects in Part B were pooled with those receiving the same dose in Part A and all subjects receiving placebo were pooled. The primary efficacy endpoint was change from baseline in Bishop score at 6, 12 and 24 h or end of study drug administration. Maternal safety evaluations included adverse events and vital signs through 4 weeks. Fetal assessments included serial heart rate monitoring and nonstress testing. Neonatal assessments included Apgar scores, NICU admissions, and adverse events through 4 weeks.

RESULTS

Overall, 74 subjects were randomized and 72 were treated. There were no significant differences between the groups receiving the highest safe dose of serelaxin (75 μg/kg/day) and placebo in the primary or secondary efficacy endpoints. Changes from baseline in Bishop score at 24 h were 4.19 ± 1.9 and 3.26 ± 2.26 in the pooled placebo and serelaxin groups, respectively (p = 0.2507). Serelaxin was well tolerated and no anti-serelaxin antibodies were detected in either subjects or neonates.

CONCLUSION

Serelaxin infusion at the end of pregnancy was well tolerated but did not advance cervical ripening.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT00259103 (15 November 2005).

Heat and air pollution exposure as triggers of delivery: A survival analysis of population-based pregnancy cohorts in Rome and Barcelona

INTRODUCTION

Environmental exposures have been linked to length of gestation but the question as to during which weeks of gestation pregnancies are most susceptible still remains little explored. We estimated the effect of maximum apparent temperature and air pollution levels on risk of birth by week of gestation.

METHODS

We analyzed two cohorts of singleton live births in Rome (2001-2010) and Barcelona (2007-2012). Maximum apparent temperature (MAT), PM10, O3 and NO2 were analyzed in the warm period (1st April-31st October). Gestational week-specific hazard ratios of giving birth associated to a 1-unit increase in exposure were estimated fitting Cox regression models adjusted for seasonality, and demographic and clinical characteristics of the mother.

RESULTS

We observed 78,633 births (5.5% preterm) in Rome and 27,255 (4.5% preterm) in Barcelona. The highest hazard ratios for 1°C increase in MAT were in the 22nd-26th weeks of gestation, 1.071, (95% CI 1.052-1.091) in Rome and 1.071 (95% CI 1.036-1.106) in Barcelona, and decreased to 1.032 (95% CI 1.026-1.038) and 1.033 (95% CI 1.020-1.045) at the 36th week of gestation, respectively. Similar associations and trends were observed for PM10 and NO2 after adjusting for MAT. O3 showed similar trends but weaker associations.

CONCLUSIONS

We found, consistently in Rome and Barcelona, an increased risk of delivery for a unit increase in MAT, PM10, NO2 and O3, especially in the second half of the second trimester, thus effectively increasing the risk of preterm and particularly early preterm birth. Results may help to increase awareness of these risks among public-health regulators and clinicians, leading to better preventive strategies.

Toll-Like Receptor 4 Is an Essential Upstream Regulator of On-Time Parturition and Perinatal Viability in Mice

An inflammatory response is instrumental in the physiological process of parturition but the upstream signals initiating inflammation are undefined. Because endogenous ligands for Toll-like receptor 4 (TLR4) are released in late gestation, we hypothesized that on-time labor requires TLR4 signaling, to trigger a cytokine and leukocyte response and accelerate the parturition cascade. In pregnant TLR4-deficient (Tlr4-/-) mice, average gestation length was extended by 13 hours and increased perinatal mortality was seen compared with wild-type controls. Quantification of cytokine and uterine activation gene expression showed that late gestation induction of Il1b, Il6, Il12b, and Tnf expression seen in control placenta and fetal membranes was disrupted in Tlr4-/- mice, and accompanied by a transient delay in expression of uterine activation genes, including prostaglandin F receptor, oxytocin receptor, and connexin-43. Leukocyte populations were altered before birth in TLR4-deficient females, with fewer neutrophils and macrophages in the placenta, and fewer dendritic cells and more regulatory T cells in the myometrium. Administration of TLR4 ligand lipopolysaccharide to pregnant wild-type mice induced cytokine expression and fetal loss, whereas Tlr4-/- pregnancies were protected. The small molecule TLR4 antagonist (+)-naloxone increased mean duration of gestation by 16 hours in wild-type mice. Collectively, these data demonstrate that TLR4 is a key upstream regulator of the inflammatory response acting to drive uterine activation and control the timing of labor. Because causal pathways for term and preterm labor converge with TLR4, interventions to manipulate TLR4 signaling may have therapeutic utility for women at risk of preterm labor, or in postterm pregnancy.

A novel misoprostol delivery system for induction of labor: clinical utility and patient considerations

Induction of labor is one of the most commonly performed obstetric procedures and will likely become more common as the reproductive population in developed nations changes. As the proportion of women undergoing induction grows, there is a constant search for more efficacious ways to induce labor while maintaining fetal and maternal safety as well as patient satisfaction. With almost half of induced labors requiring cervical ripening, methods for achieving active labor and vaginal delivery are constantly being investigated. Prostaglandins have been shown to be effective induction agents, and specifically vaginal misoprostol, used off-label, have been widely utilized to initiate cervical ripening and active labor. The challenge is to administer this medication accurately while maintaining the ability to discontinue the medication when needed. The misoprostol vaginal insert initiates cervical ripening utilizing a delivery system that controls medication release and can be rapidly removed. This paper reviews the design, development, and clinical utility of the misoprostol vaginal insert for induction of labor as well as patient considerations related to the delivery system.

Impact of prolonged dinoprostone cervical ripening on the rate of artificial induction of labor: a prospective study of 330 patients

AIM

The aim of this study was to evaluate two regimens of administration of sustained-release dinoprostone on the need for oxytocin induction of labor.

MATERIAL AND METHODS

We carried out an open prospective study comparing labor, maternal and neonatal outcomes after 12 h of prostaglandin cervical ripening insert versus 24 h of prostaglandin cervical ripening insert in 284 patients (142 ripenings at 12 h [P12 group] and 142 ripenings at 24 h [P24 group]).

RESULTS

The two groups were demographically similar. There was a significant difference in the need for artificial rupture of membranes/oxytocin induction of labor between the groups (49.3% for the P12 group vs 38% for the P24 group, P = 0.03). The delay between the beginning of ripening and delivery was significantly decreased in the P12 group, but the duration of active labor (6.6 h), the dose of oxytocics used (1326 UI), the rate of cesarean section, the rate of uterine hyperstimulation, the rates of hemorrhaging from delivery, the neonatal state and the experience of induction were similar in the two groups.

CONCLUSION

This study allows us to show for the first time that sustained-release of dinoprostone leads to spontaneous induction of labor without increasing the obstetrical risk in a majority of patients.

Eicosanomic profiling reveals dominance of the epoxygenase pathway in human amniotic fluid at term in spontaneous labor

Lipid mediators play an important role in reproductive biology, especially, in parturition. Enhanced biosynthesis of eicosanoids, such as prostaglandin E2 (PGE2) and PGF2α, precedes the onset of labor as a result of increased expression of inducible cyclooxygenase 2 (COX-2) in placental tissues. Metabolism of arachidonic acid results in bioactive lipid mediators beyond prostaglandins that could significantly influence myometrial activity. Therefore, an unbiased lipidomic approach was used to profile the arachidonic acid metabolome of amniotic fluid. In this study, liquid chromatography-mass spectrometry was used for the first time to quantitate these metabolites in human amniotic fluid by comparing patients at midtrimester, at term but not in labor, and at term and in spontaneous labor. In addition to exposing novel aspects of COX pathway metabolism, this lipidomic study revealed a dramatic increase in epoxygenase- and lipoxygenase-pathway-derived lipid mediators in spontaneous labor with remarkable product selectivity. Despite their recognition as anti-inflammatory lipid mediators and regulators of ion channels, little is known about the epoxygenase pathway in labor. Epoxygenase pathway metabolites are established regulators of vascular homeostasis in cardiovascular and renal physiology. Their presence as the dominant lipid mediators in spontaneous labor at term portends a yet undiscovered physiological function in parturition.

Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term

BACKGROUND

Prostaglandins have been used for induction of labour since the 1960s. This is one of a series of reviews evaluating methods of induction of labour. This review focuses on prostaglandins given per vaginam, evaluating these in comparison with placebo (or expectant management) and with each other; prostaglandins (PGE2 and PGF2a); different formulations (gels, tablets, pessaries) and doses.

OBJECTIVES

To determine the effects of vaginal prostaglandins E2 and F2a for third trimester cervical ripening or induction of labour in comparison with placebo/no treatment or other vaginal prostaglandins (except misoprostol).

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 March 2014) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing vaginal prostaglandins used for third trimester cervical ripening or labour induction with placebo/no treatment, with each other, or other methods listed above it on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

We assessed studies and extracted data independently.

MAIN RESULTS

Seventy randomised controlled trials (RCTs) (11,487 women) are included. In this update seven new RCTs (778 women) have been added. Two of these new trials compare PGE2 with no treatment, four compare different PGE2 formulations (gels versus tablets, or sustained release pessaries) and one trial compares PGF2a with placebo. The majority of trials were at unclear risk of bias for most domains.Overall, vaginal prostaglandin E2 compared with placebo or no treatment probably reduces the likelihood of vaginal delivery not being achieved within 24 hours. The risk of uterine hyperstimulation with fetal heart rate changes is increased (4.8% versus 1.0%, risk ratio (RR) 3.16, 95% confidence interval (CI) 1.67 to 5.98, 15 trials, 1359 women). The caesarean section rate is probably reduced by about 10% (13.5% versus 14.8%, RR 0.91, 95% CI 0.81 to 1.02, 36 trials, 6599 women). The overall effect on improving maternal and fetal outcomes (across a variety of measures) is uncertain.PGE2 tablets, gels and pessaries (including sustained release preparations) appear to be as effective as each other, small differences are detected between some outcomes, but these maybe due to chance.

AUTHORS' CONCLUSIONS

Prostaglandins PGE2 probably increase the chance of vaginal delivery in 24 hours, they increase uterine hyperstimulation with fetal heart changes but do not effect or may reduce caesarean section rates. They increase the likelihood of cervical change, with no increase in operative delivery rates. PGE2 tablets, gels and pessaries appear to be as effective as each other, any differences between formulations are marginal but may be important.

Oral misoprostol for induction of labour

BACKGROUND

Misoprostol is an orally active prostaglandin. In most countries misoprostol is not licensed for labour induction, but its use is common because it is cheap and heat stable.

OBJECTIVES

To assess the use of oral misoprostol for labour induction in women with a viable fetus.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (17 January 2014).

SELECTION CRITERIA

Randomised trials comparing oral misoprostol versus placebo or other methods, given to women with a viable fetus for labour induction.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial data, using centrally-designed data sheets.

MAIN RESULTS

Overall there were 76 trials (14,412) women) which were of mixed quality.In nine trials comparing oral misoprostol with placebo (1109 women), women using oral misoprostol were more likely to give birth vaginally within 24 hours (risk ratio (RR) 0.16, 95% confidence interval (CI) 0.05 to 0.49; one trial; 96 women), need less oxytocin (RR 0.42, 95% CI 0.37 to 0.49; seven trials; 933 women) and have a lower caesarean section rate (RR 0.72, 95% CI 0.54 to 0.95; eight trials; 1029 women).In 12 trials comparing oral misoprostol with vaginal dinoprostone (3859 women), women given oral misoprostol were less likely to need a caesarean section (RR 0.88, 95% CI 0.78 to 0.99; 11 trials; 3592 women). There was some evidence that they had slower inductions, but there were no other statistically significant differences.Nine trials (1282 women) compared oral misoprostol with intravenous oxytocin. The caesarean section rate was significantly lower in women who received oral misoprostol (RR 0.77, 95% CI 0.60 to 0.98; nine trials; 1282 women), but they had increased rates of meconium-stained liquor (RR 1.65, 95% CI 1.04 to 2.60; seven trials; 1172 women).Thirty-seven trials (6417 women) compared oral and vaginal misoprostol and found no statistically significant difference in the primary outcomes of serious neonatal morbidity/death or serious maternal morbidity or death. The results for vaginal birth not achieved in 24 hours, uterine hyperstimulation with fetal heart rate (FHR) changes, and caesarean section were highly heterogenous - for uterine hyperstimulation with FHR changes this was related to dosage with lower rates in those with lower doses of oral misoprostol. However, there were fewer babies born with a low Apgar score in the oral group (RR 0.60, 95% CI 0.44 to 0.82; 19 trials; 4009 babies) and a decrease in postpartum haemorrhage (RR 0.57, 95% CI 0.34 to 0.95; 10 trials; 1478 women). However, the oral misoprostol group had an increase in meconium-stained liquor (RR 1.22, 95% CI 1.03 to 1.44; 24 trials; 3634 women).

AUTHORS' CONCLUSIONS

Oral misoprostol as an induction agent is effective at achieving vaginal birth. It is more effective than placebo, as effective as vaginal misoprostol and results in fewer caesarean sections than vaginal dinoprostone or oxytocin.Where misoprostol remains unlicensed for the induction of labour, many practitioners will prefer to use a licensed product like dinoprostone. If using oral misoprostol, the evidence suggests that the dose should be 20 to 25 mcg in solution. Given that safety is the primary concern, the evidence supports the use of oral regimens over vaginal regimens. This is especially important in situations where the risk of ascending infection is high and the lack of staff means that women cannot be intensely monitored.

Estimation of shear wave speed in the human uterine cervix

OBJECTIVES

To explore spatial variability within the cervix and the sensitivity of shear wave speed (SWS) to assess softness/stiffness differences in ripened (softened) vs unripened tissue.

METHODS

We obtained SWS estimates from hysterectomy specimens (n = 22), a subset of which were ripened (n = 13). Multiple measurements were made longitudinally along the cervical canal on both the anterior and posterior sides of the cervix. Statistical tests of differences in the proximal vs distal, anterior vs posterior and ripened vs unripened cervix were performed with individual two-sample t-tests and a linear mixed model.

RESULTS

Estimates of SWS increase monotonically from distal to proximal longitudinally along the cervix, they vary in the anterior compared to the posterior cervix and they are significantly different in ripened vs unripened cervical tissue. Specifically, the mid position SWS estimates for the unripened group were 3.45 ± 0.95 m/s (anterior; mean ± SD) and 3.56 ± 0.92 m/s (posterior), and 2.11 ± 0.45 m/s (anterior) and 2.68 ± 0.57 m/s (posterior) for the ripened group (P < 0.001).

CONCLUSIONS

We propose that SWS estimation may be a valuable research and, ultimately, diagnostic tool for objective quantification of cervical stiffness/softness.

Term induction of labor and subsequent preterm birth

OBJECTIVE

Although the rate of inductions continues to rise, there is a paucity of data investigating subsequent pregnancy outcomes after induction. Our objective was to compare term inductions with term spontaneous labor and evaluate the rate of subsequent spontaneous preterm birth (sPTB).

STUDY DESIGN

A retrospective cohort study of women with 2 consecutive deliveries from 2005 through 2010 was performed. Term inductions or term spontaneous labor in the index pregnancy was included, and those with a prior sPTB were excluded. Data were obtained through chart abstraction. The primary outcome was sPTB (<37 weeks) in a subsequent pregnancy. Categorical variables were compared with χ(2) analyses, and logistic regression was used to calculate odds.

RESULTS

Eight hundred eighty-seven women were included (622 inductions, 265 spontaneous labor). The overall subsequent sPTB rate was 7.2%. Term inductions were less likely to have a subsequent sPTB compared with term spontaneous labor (6% vs 11%; odds ratio [OR], 0.49; 95% confidence interval, 0.29-0.81; P = .005). This remained after adjusting for confounders (adjusted OR, 0.55; P = .04). The sPTB risk depended on gestational age of index delivery. At 37-38.9 weeks, the sPTB rate after spontaneous labor was 24% vs 9% after induction (OR, 3.0; 95% confidence interval, 1.44-6.16; P = .003). This was not significant for 39-39.9 weeks (P = .2) or 40 weeks or longer (P = .8).

CONCLUSION

Induction is not a risk factor for subsequent sPTB. Spontaneous labor, however, in the early term period is associated with subsequent sPTB. Further investigation among early term deliveries is warranted to evaluate the risk of sPTB and target interventions in this cohort.

Prostaglandin E2 regulates its own inactivating enzyme, 15-PGDH, by EP2 receptor-mediated cervical cell-specific mechanisms

CONTEXT

Prostaglandins play important roles in parturition and have been used to induce cervical ripening and labor. Prior to cervical ripening at term, 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is highly expressed in the cervix and metabolizes cyclooxygenase-2-mediated increases in active prostaglandin E2 (PGE2) to inactive 15-keto PGE2. At term, 15-PGDH gene expression decreases and PGE2 accumulates, leading to cervical ripening and labor. Previously, we found that the cervical isoform of microphthalmia-associated transcription factor (MiTF-CX) serves as a progestational transcription factor that represses IL-8 and hypoxia-mediated increases in cyclooxygenase-2.

OBJECTIVE

We tested the hypothesis that PGE2 regulates its own inactivation through MiTF-CX.

DESIGN

We used human cervical stromal cells to investigate the regulation of 15-PGDH.

SETTING

This was a laboratory-based study using cells from clinical tissue samples.

MAIN OUTCOME MEASURES

We evaluated the mechanisms by which PGE2 regulates 15-PGDH in human cervical stromal cells.

RESULTS

PGE2 repressed MiTF-CX and 15-PGDH, whereas ectopic overexpression of MiTF-CX induced 15-PGDH expression levels. Stabilization of HIF-1α by deferoxamine resulted in concomitant down-regulation of MiTF-CX and 15-PGDH. Ectopic overexpression of MiTF-CX abrogated PGE2- and deferoxamine-mediated loss of MiTF-CX and 15-PGDH. PGE2-induced loss of MiTF-CX and 15-PGDH was mediated through prostaglandin E2 receptor (EP2) receptors (PTGER2), but not cAMP.

CONCLUSIONS

The 15-PGDH gene is a MiTF-CX target gene in cervical stromal cells and is down-regulated by PGE2 through EP2 receptors. The findings suggest that EP2 receptor-specific antagonists may be used as an adjunct to present clinical management for the prevention of preterm cervical ripening and preterm labor.

Timing of delivery in women with diabetes in pregnancy

The incidence of both gestational and pre-gestational diabetes is increasing worldwide. The main cause of this increase is likely the concomitant increase in the incidence of global obesity, but in the case of gestational diabetes, changes in the diagnostic criteria are also a contributing factor. The adverse outcomes associated with pre-gestational diabetes are well known and have led clinicians to implement various strategies that include increased fetal surveillance and induction of labour at various gestational ages. In many cases these same strategies have been applied in clinical practice also to women with gestational diabetes despite there being differences in the type and magnitude of perinatal complications associated with this diagnosis. Despite the widespread application of these clinical practices, there is a paucity of quality data in the medical literature to guide the clinician in choosing a strategy for fetal surveillance and timing of delivery in both gestational diabetes and pre-gestational diabetes pregnancies. In the following review, we will discuss the rationale and consequences of planned delivery in gestational diabetes and pre-gestational diabetes, the evidence supporting different strategies for delivery and finally highlight future targets for research in this area.

Induction of labour

OBJECTIVE

To review the most current literature in order to provide evidence-based recommendations to obstetrical care providers on induction of labour.

OPTIONS

Intervention in a pregnancy with induction of labour.

OUTCOMES

Appropriate timing and method of induction, appropriate mode of delivery, and optimal maternal and perinatal outcomes.

EVIDENCE

Published literature was retrieved through searches of PubMed, CINAHL, and The Cochrane Library in 2010 using appropriate controlled vocabulary (e.g., labour, induced, labour induction, cervical ripening) and key words (e.g., induce, induction, augmentation). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to the end of 2010. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The evidence in this document was rated using criteria described in the Report of the Canadian Task Force on Preventative Health Care (Table 1). SUMMARY STATEMENTS: 1. Prostaglandins E(2) (cervical and vaginal) are effective agents of cervical ripening and induction of labour for an unfavourable cervix. (I) 2. Intravaginal prostaglandins E(2) are preferred to intracervical prostaglandins E(2) because they results in more timely vaginal deliveries. (I).

The risk factors for failure of labor induction: a cohort study

PURPOSE

To assess how some factors may influence the failure of labor induction.

METHODS

We conducted a prospective observational study from January 2009 to December 2011 with 248 patients who were admitted to the Obstetrics Unit of Ferrara University for labor induction. We selected only patients with unfavorable characteristics such as nulliparity, maternal and gestational age, and Bishop score and specific obstetric conditions such as mild preeclampsia, isolated oligohydramnios, premature rupture membrane, gestational diabetes, and hypertension for the success of labor induction.

RESULTS

The induction was carried out by rapid-release gel dinoprostone. 200 patients (80.6 %) delivered vaginally (Group A), while 48 (19.4 %) underwent a cesarean section (Group B). Maternal age was one independent significant variable (p = 0.01, OR 1.08) determining the risk of cesarean delivery. Patients affected by mild preeclampsia had a three times higher risk for cesarean section. Despite the several unfavorable characteristics of the patients, the cesarean section rate was comparable to that of the normal population.

CONCLUSIONS

Several factors and clinical conditions historically considered as negative predictors of induction result should be reassessed. The success of labor induction is determined by many maternal and fetal variables, which must all be taken into account to avoid unnecessary cesarean sections.

Acupuncture for induction of labour

BACKGROUND

This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology. The use of complementary therapies is increasing and some women look to complementary therapies during pregnancy and childbirth to be used alongside conventional medical practice. Acupuncture involves the insertion of very fine needles into specific points of the body. The limited observational studies to date suggest acupuncture for induction of labour appears safe, has no known adverse effects to the fetus, and may be effective. However, the evidence regarding the clinical effectiveness of this technique is limited.

OBJECTIVES

To determine the effectiveness and safety of acupuncture for third trimester cervical ripening or induction of labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (23 November 2012), PubMed (1966 to 23 November 2012), Embase (1980 to 23 November 2012), Dissertation Abstracts (1861 to 23 November 2012), CINAHL (1982 to 23 November 2012), the WHO International Clinical Trials Registry Portal (ICTRP) (23 November 2012) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing acupuncture used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, evaluated methodological quality and extracted data.

MAIN RESULTS

The original review included three trials and seven trials were excluded. This updated review includes 14 trials, and excludes eight trials. Three trials previously excluded due to no clinically relevant outcomes are now included. Eight new trials were included, and four new trials were excluded. We included 14 trials with data reporting on 2220 women.Trials reported on three primary outcomes only caesarean section, serious neonatal morbidity and maternal mortality. No trial reported on vaginal delivery not achieved within 24 hours; and uterine hyperstimulation with fetal heart rate (FHR) changes. There was no difference in caesarean deliveries between acupuncture and the sham control (average risk ratio (RR) 0.95, 95% confidence interval (CI) 0.69 to 1.30, six trials, 654 women), and acupuncture versus usual care (average RR 0.69, 95% CI 0.40, 1.20, six trials, 361 women). There was no difference in neonatal seizures between acupuncture and the sham group (RR 1.01, 95% CI 0.06 to 16.04, one trial, 364 women).There was some evidence of a change in cervical maturation for women receiving acupuncture compared with the sham control, (mean difference (MD) 0.40. 95%CI 0.11 to 0.69, one trial, 125 women), and when compared with usual care (MD 1.30, 95% CI 0.11 to 2.49, one trial, 67 women). The length of labour was shorter in the usual care group compared with acupuncture (average standardised mean difference (SMD) 0.67, 95% CI 0.18 to 1.17, one trial 68 women). There were no other statistically significant differences between groups. Few studies reported on many clinically relevant outcomes. One trial was at a low risk of bias on all domains.

AUTHORS' CONCLUSIONS

Overall, there have been few studies assessing the role of acupuncture for induction of labour. Before implications for clinical practice can be made there is a need for well-designed randomised controlled trials to evaluate the role of acupuncture to induce labour and for trials to assess clinically meaningful outcomes.

Castor oil, bath and/or enema for cervical priming and induction of labour

BACKGROUND

Castor oil, a potent cathartic, is derived from the bean of the castor plant. Anecdotal reports, which date back to ancient Egypt have suggested the use of castor oil to stimulate labour. Castor oil has been widely used as a traditional method of initiating labour in midwifery practice. Its role in the initiation of labour is poorly understood and data examining its efficacy within a clinical trial are limited. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

OBJECTIVES

To determine the effects of castor oil or enemas for third trimester cervical ripening or induction of labour in comparison with other methods of cervical ripening or induction of labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2013) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing castor oil, bath or enemas used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction.

MAIN RESULTS

Three trials, involving 233 women, are included. There was no evidence of differences in caesarean section rates between the two interventions in the two trials reporting this outcome (risk ratio (RR) 2.04, 95% confidence interval (CI) 0.92 to 4.55). There were no data presented on neonatal or maternal mortality or morbidity.There was no evidence of a difference between castor oil and placebo/no treatment for the rate of instrumental delivery, meconium-stained liquor, or Apgar score less than seven at five minutes. The number of participants was too small to detect all but large differences in outcome. All women who ingested castor oil felt nauseous (RR 59.92, 95% CI 8.46 to 424.52).

AUTHORS' CONCLUSIONS

The three trials included in the review contain small numbers of women. All three studies used single doses of castor oil. The results from these studies should be interpreted with caution due to the risk of bias introduced due to poor methodological quality. Further research is needed to attempt to quantify the efficacy of castor oil as an cervical priming and induction agent.

The transcervical foley catheter versus the vaginal prostaglandin e2 gel in the induction of labour in a previous one caesarean section - a clinical study

OBJECTIVE

To compare the effectiveness and the safety of the transcervical Foley catheter and the prostaglandin E2 (PGE2) gel for the induction of labour in women with a previous one caesarean section with an unfavourable cervix at term.

METHOD

This study was conducted in the Department of Obstetrics and Gynaecology, J.N. Medical College, Aligarh, (U.P),India. Seventy women with singleton pregnancies at term, with previous one lower segment caesarean sections with a cephalic presentation and a Bishop's score of ≤ 6, who required induction at term were included in the study. Group A had 35 women in whom the transcervical Foley catheter was inserted and Group B included 35 women in whom the PGE2 gel was inserted vaginally for the induction of labour.The Bishop's score after 12 hours of induction, the oxytocin requirement, the induction to delivery interval, the mode of delivery, the maternal complications and the neonatal outcome were compared.

RESULTS

The Foley catheter and the PGE2 gel had a comparable effect on the Bishop's score after 12 hours and the induction to the delivery interval was slightly shorter with the Foley catheter (18.15 hours) as compared to 21.06 hours with the PGE2 gel. There was no case of uterine rupture or scar dehiscence.

CONCLUSION

In this study, both the modes of induction in women with previous one caesarean sections were safe, simple and effective. The main advantages of the cervical ripening with the Foley catheter over the Prostaglandin E2 gel are the low cost, reversibility and the lower risk of systemic and serious side effects like uterine hyperstimulation and rupture, as well as it induces a significant ripening and dilatation of the cervix and a shorter induction to the delivery interval. So, the cervical ripening effect of the Foley catheter is as good as that of the Prostaglandin E2 gel in women with previous one caesarean sections.

Oxytocin versus sustained-release dinoprostone vaginal pessary for labor induction of unfavorable cervix with Bishop score ≥ 4 and ≤ 6: a randomized controlled trial

AIM

To compare the efficacy and safety of high-dose intravenous oxytocin and sustained-release dinoprostone vaginal pessaries for cervical ripening and labor induction in pregnant patients at term with poor Bishop scores.

MATERIAL AND METHODS

Women at term with a Bishop score ≥ 4 and ≤ 6 were randomized into two groups to undergo induction of labor with either high-dose oxytocin administered intravenously (n = 90) or dinoprostone-only vaginal pessary without oxytocin augmentation (n = 90). The main outcome measures were rate of cesarean delivery, induction to delivery interval, number of deliveries achieved within 4, 8, 12, and 16 h of labor induction, maternal complications during induction, fetal outcome, and total hospital stay. In this study, per-protocol analysis was performed.

RESULTS

There were fewer cesarean deliveries with oxytocin compared to dinoprostone-only groups (7/79 vs 14/89); however, the difference was not statistically significant. The induction-delivery intervals (7.9 h vs 12.0 h, P < 0.001; and 5.7 vs 10.4 h, P < 0.001; oxytocin vs dinoprostone-only for primiparous and multiparous patients, respectively) were significantly shorter in oxytocin-induced patients compared to dinoprostone-only. A significantly higher percentage of patients delivered in the oxytocin group compared to the dinoprostone-only group in 4, 8, 12, 16, and 20 h.

CONCLUSION

Intravenous oxytocin is effective to stimulate labor at term for patients with Bishop scores ≥ 4 and ≤ 6, with a shorter time interval from induction to vaginal delivery.

Women's experiences of outpatient induction of labour with remote continuous monitoring

OBJECTIVE

to gain insight into women's experiences and preferences for induction in the home as part of a trial investigating the feasibility and acceptability of outpatient induction of labour with remote monitoring.

DESIGN

a qualitative study using semi-structured individual interviews. Interview transcripts were subjected to thematic analysis to identify the dominant themes regarding women's experiences of outpatient induction.

SETTING

a large maternity hospital in the North West of England.

PARTICIPANTS

fifteen women who participated in the main trial of outpatient induction of labour with remote continuous monitoring.

FINDINGS

three main themes were identified; the need for women to 'labour within their comfort zone'; their desire to achieve 'the next best thing to a normal labour' and the importance of a 'virtual presence' to offer remote reassurance.

CONCLUSIONS

women's preference for the outpatient setting of induction of labour is dominated by their need to labour within their comfort zone. Outpatient induction offered women the familiarity and freedom of the home environment, and the resulting physical and emotional comforts helped women cope better with their labour and improved their birth experiences. While remote monitoring offered some reassurance, women still depended on effective communication from hospital staff to provide the virtual presence of a health professional in the home.

IMPLICATIONS

the combination of slow-release prostaglandin and a remote monitoring device may provide low risk women with an improved induction and labour experience. While ongoing studies continue to explore further the safety of interventions at home, this study has importantly considered women's views and confirmed that induction at home is not only acceptable to women but also that the outpatient experience is preferable to long inpatient inductions.

In vitro myometrial contractility profiles of different pharmacological agents used for induction of labor

OBJECTIVE

To investigate the effects of different pharmacological induction agents on myometrial contractility.

STUDY DESIGN

Myometrial biopsies were obtained from 13 term nonlaboring women undergoing scheduled cesarean delivery. Tissue strips were suspended in organ chambers for isometric tension recording. The effects of cumulative doses (10-10 mol/L to 10-5 mol/L) of prostaglandin E1 (PGE1), E2 (PGE2), and oxytocin on spontaneous uterine contractility were determined. Areas under the contraction curve were compared using one-way analysis of variance on ranks with Dunn post hoc test.

RESULTS

Oxytocin-induced myometrial contractility was superior to PGE1, PGE2, and time controls (CTR) at all the concentrations tested. When only prostaglandins were compared with CTR, PGE1 10-5 mol/L increased myometrial contractility, and PGE2 had no effects.

CONCLUSION

Oxytocin and prostaglandins have different effects on myometrial contractility accounting for different mechanisms of action and side effects. The increased uterine contractility observed with PGE1 as compared with PGE2 can contribute to explain the higher success of vaginal delivery.

Dinoprostone vaginal pessary for induction of labour: safety of use for up to 24 h

BACKGROUND

Cervidil(®) (dinoprostone) intravaginal pessaries are used for induction of labour and maintain serum prostaglandin levels for up to 24 h. The Therapeutic Goods Administration approves Cervidil(®) for 12-h use. However, twenty-four-hour use of Cervidil(®) is supported in Europe, New Zealand, America and some Australian hospitals.

AIM

To assess the safety of Cervidil(®) use for up to 24 h for induction of labour in nulliparous women.

METHODS

A retrospective cohort study of 269 consecutive women receiving Cervidil(®) at the Royal Brisbane and Women's Hospital (RBWH) between July 2007 and December 2008 was performed. The primary outcome measures were frequency of, and time to, uterine tachysystole with or without fetal heart rate (FHR) changes. Secondary outcome measures included frequency of maternal (intrapartum temperature, postpartum haemorrhage) and neonatal (low Apgars, resuscitation, nursery admission) morbidity. Morbidity outcomes of those who received Cervidil(®) for less than or equal to 12 h were compared with those who received Cervidil(®) for more than 12 h.

RESULTS

Uterine tachysystole occurred in 9.3% of patients receiving Cervidil(®) , with a mean time to tachysystole of 10 h. The majority of cases (68%) occurred within 12 h of use. There was no increase in maternal or neonatal morbidity for those who received Cervidil(®) for longer than 12 h.

CONCLUSION

Twenty-four-hour use of Cervidil(®) is likely as safe as 12-h use for induction of labour in nulliparous women.

The effects of prostaglandin E1 and prostaglandin E2 on in vitro myometrial contractility and uterine structure

OBJECTIVE

To estimate the effects of prostaglandin E1 (PGE1) and E2 (PGE2) on myometrial contractility and structure in vitro.

STUDY DESIGN

Myometrial strips from 18 women were incubated with PGE1 (10-5 mol/L), PGE2 (10-5 mol/L), or solvent (CTR) for up to 360 minutes in organ chambers for isometric tension recording. The area under the contraction curve, total collagen content, and percentage of the area covered by connective tissue were calculated at various time periods.

RESULTS

PGE1 significantly increased in vitro myometrial contractility up to 90 minutes when compared with PGE2 and CTR (p < 0.01) and up to 180 minutes as compared with PGE2 (p < 0.05). After 360 minutes, CTR and PGE1 samples had lower total collagen content and area covered by connective tissue than PGE2 (p < 0.01).

CONCLUSION

The effects of prostaglandins on the uterus cannot be solely explained by contractility. Treatment with PGE1 significantly increased myometrial contractions and decreased both total collagen content and the area covered by connective tissue. Such findings may explain the higher rates of vaginal delivery, tachysystole, and uterine rupture associated with PGE1 use.

A randomized trial of preinduction cervical ripening: dinoprostone vaginal insert versus double-balloon catheter

OBJECTIVE

We sought to compare the efficacy of a double-balloon transcervical catheter to that of a prostaglandin (PG) vaginal insert among women undergoing labor induction.

STUDY DESIGN

In all, 210 women with a Bishop score ≤6 were assigned randomly to cervical ripening with either a double-balloon device or a PGE2 sustained-release vaginal insert. Primary outcome was vaginal delivery within 24 hours.

RESULTS

The proportion of women who achieved vaginal delivery in 24 hours was higher in the double-balloon group than in the PGE2 group (68.6% vs 49.5%; odds ratio, 2.22; 95% confidence interval, 1.26-3.91). There was no difference in cesarean delivery rates (23.8% vs 26.2%; odds ratio, 0.88; 95% confidence interval, 0.47-1.65). Oxytocin and epidural analgesia were administered more frequently when a double-balloon device was used. Uterine tachysystole or hypertonus occurred more frequently in the PGE2 arm (9.7% vs 0%, P = .0007).

CONCLUSION

The use of a double-balloon catheter for cervical ripening is associated with a higher rate of vaginal birth within 24 hours compared with a PGE2 vaginal insert.

Home labour induction with retrievable prostaglandin pessary and continuous telemetric trans-abdominal fetal ECG monitoring

Objective

To evaluate the feasibility of continuous telemetric trans-abdominal fetal electrocardiogram (a-fECG) in women undergoing labour induction at home.

Study Design

Low risk women with singleton term pregnancy undergoing labour induction with retrievable, slow-release dinoprostone pessaries (n = 70) were allowed home for up to 24 hours, while a-fECG and uterine activity were monitored in hospital via wireless technology. Semi-structured diaries were analysed using a combined descriptive and interpretive approach.

Results

62/70 women (89%) had successful home monitoring; 8 women (11%) were recalled because of signal loss. Home monitoring lasted between 2–22 hours (median 10 hours). Good quality signal was achieved most of the time (86%, SD 10%). 3 women were recalled back to hospital for suspicious a-fECG. In 2 cases suspicious a-fECG persisted, requiring Caesarean section after recall to hospital. 48/51 women who returned the diary coped well (94%); 46/51 were satisfied with home monitoring (90%).

Conclusions

Continuous telemetric trans-abdominal fetal ECG monitoring of ambulatory women undergoing labour induction is feasible and acceptable to women.