Preinduction cervical priming in high risk pregnancy — experience with a new sustained release PGE2 vaginal film

Experience with a new sustained release PGE2 formulation is presented. 111 high risk primiparae with very poor cervical scores (<3) were studied. In 59 patients, labour was induced by forewater amniotomy and I.V. oxytocin. In the remaining 52 patients, film containing 850 ug of PGE₂ was inserted into the vagina to ripen the cervix 24 hours prior to induction of labour. Indications for elective delivery and maternal characteristics were similar in both groups. There were significant changes in the cervical state within 12 hours of vaginal insertion. By 24 hours, 19 patients receiving vaginal film (36.5%) had established labour of whom 13 proceeded to vaginal delivery. Significantly fewer patients in the priming group required Caesarean delivery. No untoward maternal or fetal side effects were observed.Safety, ease of administration and efficacy make this new PGE₂ formulation a useful agent for priming of the very poor primiparous cervix prior to induction of high risk labour.     

Preinduction cervical priming with PGE2 vaginal film in primigravidae--a randomised, double blind, placebo controlled study

Previous reports with an 850 micrograms prostaglandin E2 film for cervical ripening before induction of labour in term pregnancy have been favourable. These studies however had no controls. The present study compares this PGE2 vaginal film with a nonmedicated similar vaginal film (placebo) for preinduction cervical ripening in primigravid women at term. A total of 69 women with modified Bishop's cervical scores 1-5 were assigned randomly to either the PGE2 group (33 women) or placebo group (36 women). Cervical score assessments were made at 12 and 24 hours after which labour was induced by amniotomy and oxytocin infusion. Although the cervical scores between placebo and PGE2 groups at 12 and 24 hours were not significantly different, the scores were marginally better with the prostaglandin film. Pregnancy outcome was satisfactory in both groups with no perinatal or maternal mortality and morbidity. The caesarean rate was 30.6% in the placebo group and 24.2% in the PGE2 group. This study emphasizes the need for a control group when studying the success of agents used for ripening the pregnant cervix at term.     

Selective induction of labour following administration of an oral prostaglandin E2 0.5 mg tablet hourly

Induction of labour was performed on 20 patients with favourable induction features by amniotomy and administration of a fixed dose of 0.5 mg of prostaglandin E₂ (PGE₂) hourly. Effective uterine action resulted in a mean time to delivery of 6 hrs 57 mins in primagravid patients and 4 hrs 40 mins in multigravid subjects. In two patients an intravenous oxytocin infusion was used to assist labour. There were no significant maternal or fetal side effects.     

Experience with prostaglandin F2α (free acid) for the induction of labour

Labour was induced or augmented in 115 patients by amniotomy followed by intravenously administered prostaglandin F_2α (PGF_2α). The results were compared to those obtained retrospectively from a similar number of patients, matched for age, parity, induced and augmented labour, epidural anaesthesia and induction score; in whom labour had been induced by amniotomy followed by intravenous oxytocin titration. Both regimes were very effective, but there was a higher incidence of side effects in the patients receiving oxytocin. There was one maternal death associated with Prostaglandin infusion. Labour was also induced in a further group of 50 patients by amniotomy followed by oral PGF_2α (free acid). 42 patients (84%) were successfully induced. Vomiting and diarrhoea occurred in 22 patients (45%).     

Comparative study of a two dose schedule of PGE2 3 mg pessary and 1700 micrograms film for induction of labour in nulliparae with poor cervical score

Efficacy of a two dose schedule of 3 mg pessary or 1700 micrograms film of PGE2 for induction of labour was compared in nulliparae with poor cervical score. Patient characteristics in the two groups (43 in 3 mg and 40 in 1700 micrograms group) were comparable in age, period of gestation, indications for induction of labour and in their initial cervical score. The number of patients who started labour with a two dose schedule 4 hours apart were similar in each group. The improvement of cervical score, length of labour, mode of delivery and the neonatal outcome were not different in the two groups. There was no advantage of using a film preparation over that in the form of a pessary and the use of 3 mg dose did not give significantly better results compared with the 1700 micrograms dose, in terms of obstetric or neonatal outcome.     

Induction of labour by low amniotomy and oral administration of a solution compared to a tablet of prostaglandin E2

Labour was induced in 35 women by low amniotomy and the simultaneous oral administration of prostaglandin E₂ tablets (0.5 mg) hourly. The results of this group are compared to those of a similar number of patients who had labour induced by low amniotomy and the simultaneous administration of oral prostaglandin E₂ solution. There were no clinically significant differences between the two groups. Both methods are effective adjuncts to low amniotomy for the induction of labour, with an acceptable incidence of side effects.     

Fetal effects of cervical ripening with extra-amniotic prostaglandin E2 in gel

A gel containing 0.5 mg prostaglandin E2 (PGE2) was extra-amniotically instilled to 90 clinically normal gravidae at term, for ripening of the cervix before elective induction of labor by amniotomy and intravenous PGE2. An acceptable increase in the Bishop score was noted to have occurred in 87/90 women, when assessed eight hours after administration of the gel; 14 of these women were then in established labor, which progressed uneventfully. Four of the 90 subjects required cesarean section for cephalopelvic disproportion. No adverse maternal or fetal effects of the procedure were detected under careful clinical, electronic and biochemical monitoring. However, epidural anesthesia adversely influenced the acid-base equilibrium of the fetus.     

Induction of human labor at term: uterine activity, inducibility, duration and neonatal jaundice

A total of 821 patients, 39-40 weeks pregnant, was obstetrically normal at admission. In 212 of them intra-uterine pressure (IUP) was monitored before and during inducing labor by oxytocin, in 212 patients delivery was also induced by oxytocin but not monitored, in 197 by combining oxytocin and amniotomy, and 200 had spontaneous delivery. Inducibility could be predicted by uterine baseline activity and a 50 mu i.v. shot of oxytocin, together with determination of cervical status and placental location. The duration of labour induction was affected by parity, placental location and cervical status, but was predicted only to a minor degree by baseline activity and uterine oxytocin sensitivity. Amniotomy did not affect caesarean, section rate. The newborn child benefited from IUP monitoring: fewer transfers to pediatrics were necessary, there was less neonatal jaundice and fewer blood exchanges. It is assumed that if labor is not monitored through IUP, oxytocin may cause neonatal hyperbilirubinaemia through episodes of increased uterine resting pressure.     

Clinical evaluation of endocervical prostaglandin E2-triacetin-gel for preinduction cervical softening in pregnant women at term

In an open randomized clinical trial 100 pregnant women with low Bishop Scores at term were treated either with intracervical Prostaglandin (PG) E2 (0.5 mg in 2.5 ml triacetin-gel) 12 hours before labor induction with intravenous oxytocin or with oxytocin infusion alone. In 46 of the 50 pretreated patients (92%) the Bishop Score progressed at least 3 points, in four cases only 2 points. The mean Bishop score in the untreated patients increased insignificantly. After PGE2-gel administration 16 patients delivered during the 12 hour interval compared to 3 in the group without pretreatment. The first induction attempt was successful in 14 (64%) of the 22 patients that were left to be induced after cervical softening and in 26 (57%) of the 47 women without cervical priming. The Cesarean section rate was 10% (n = 5) in the PGE2-gel group and 12% (n = 6) in the control group. Dosage of oxytocin required for labor induction was significantly lower after cervical softening. No serious fetal or maternal side effects were observed after PGE2 pretreatment.     

Use of prostaglandin E2 to ripen the cervix of the mare prior to induction of parturition

Eleven light-breed pregnant mares (335 to 347 d gestaton) were used to evaluate the use of prostaglandin E2 as a cervical ripening agent prior to induction of parturition during the months of April and May. Six hours prior to induction, each mare's cervix was examined per vagina for softness and dilation. Each mare was then assigned to 1 of 2 treatment groups: Group PGE mares (n = 7) received 2.0 to 2.5 mg prostaglandin E2 deposited intracervically; Group SAL mares (n = 4) received 0.5 mL of sterile NaCl deposited intracervically. Six hours later, the mares were readied for parturition by wrapping the tail, scrubbing and rinsing the perineum and udder, and examining the cervix as previously described. Each mare was then administered 15 U, i.v. oxytocin at 15-min intervals until the chorioallantois ruptured. Intervals from initial oxytocin injection until rupture of the chorioallantois, from initial oxytocin injection until delivery of the foal, from delivery of the foal until the foal stood unassisted, and from delivery of the foal until the foal suckled were recorded. Mean cervical dilation immediately prior to induction of parturition tended to be greater in Group PGE mares (3.9 +/- 1.7 cm) than in Group SAL mares (1.9 +/- 1.9 cm; P = 0.10). Mean change in cervical dilation over the 6-h period prior to induction (3.4 +/- 1.9 cm vs 1.5 +/- 2.1 cm), mean number of injections of oxytocin required until the chorioallantois ruptured (1.9 +/- 0.7 vs 2.5 +/- 1.0), and mean intervals from initial injection of oxytocin to rupture of the chorioallantois (20 +/- 10 min vs 28 +/- 19 min) and delivery of the foal (28 +/- 7 min vs 34 +/- 22 min) were not different between Group PGE and SAL mares, respectively (P > 0.10). The proportion of foals that stood within 1 h of birth also did not differ between Group PGE foals (6/7; 86%) and Group SAL foals (3/4; 75%; Chi-square = 0.17; P > 0.10). The proportion of foals that nursed within 2 h of birth was higher in Group PGE foals (6/7; 86%) than in Group SAL foals (1/4; 25%; Chi-square = 4.02; P < 0.05). Premature separation requiring manual rupture of the chorioallantois at the vulvar labia occurred in 1 Group PGE mare (cervical dilation of 1.5 cm at time of induction) and 1 Group SAL mare (cervix closed and firm at time of induction). Foals born from the 2 mares with premature placental separation had the longest intervals from initial oxytocin injection to delivery, delivery to ability to stand unassisted, and delivery to suckling within their respective treatment groups. In summary, it appears that cervical ripening prior to induction of parturition favors shorter deliveries and foal vigor. Intracervical administration of prostaglandin E2 may prove useful for ripening the cervix of the mare prior to induction of parturition. Further studies are indicated to determine optimal dosage and method of administration of prostaglandin E2.     

Single shot prostaglandin gel for labor induction.

A viscous suspension of prostaglandin E2 was introduced endocervically to induce labor in patients with favourable induction features. The method was found to be effective and compared favourably with the conventional practices of amniotomy and intravenous oxytocin infusion or oral prostaglandin therapy. Several advantages were found including a high degree of patient acceptability.     

Single shot prostaglandin gel for labor induction

A viscous suspension of prostaglandin E₂ was introduced endocervically to induce labor in patients with favourable induction features. The method was found to be effective and compared favourably with the conventional practices of amniotomy and intravenous oxytocin infusion or oral prostaglandin therapy. Several advantages were found including a high degree of patient acceptability.     

Active management of labour: current knowledge and research issues.

OBJECTIVES--To review the evidence that the package of labour interventions collectively called "active management"--namely, strict diagnostic criteria for labour, early amniotomy, early use of oxytocin, and continuous professional support--reduce rates of caesarean sections and operative vaginal delivery in first labours. DESIGN--Review of observational data, supplemented by evidence from four separate overviews of relevant randomised trials previously published as part of the Cochrane Collaboration pregnancy and childbirth database. RESULTS--Observational data do not permit a clear conclusion. There have been no randomised trials of the total package of active management or of the use of strict diagnostic criteria alone, but trials of early amniotomy, early oxytocin, and these interventions combined do not suggest that these interventions are effective in reducing rates of caesarean sections or operative vaginal deliveries. In contrast, the provision of continuous professional support in labour seems to reduce both types of operative delivery, although the effect on caesarean sections is confined to those settings where non-professional companions are not normally present in labour. CONCLUSIONS--Delivery units should endeavour to provide continuous professional support in labour, but routine use of amniotomy and early oxytocin is not recommended.     

Induction of Labour by Simultaneous Intravenous Administration of Prostaglandin E2 and Oxytocin

In a group of 20 matched primigravid patients labour was induced by forewater amniotomy followed by intravenous oxytocin (Syntocinon) administered in escalating doses. Ten of these patients, in a double-blind trial, also received prostaglandin E₂ infused simultaneously with the oxytocin. In the combined prostaglandin-oxytocin group there was a noticeable reduction in the dosage of oxytocin required to produce effective uterine action, and the duration of labour was also reduced. No side effects were observed.     

Patients' attitudes to induction and labour.

An attempt was made to ascertain patients'' attitudes towards planned induction and labour. Twenty per cent of patients had not heard of induction before their pregnancy, and those who had had most probably heard about it from relations and friends rather than the media. Most patients had no firm opinions on induction of labour but were usually glad to have their pregnancy ended. Many considered that they had not been given enough information by the medical staff on their induction. The amount of pain experienced by patients at amniotomy was related to the "favourability" of the cervix. Possibly women with a low cervical score should be given more premedication or inhalation analgesia at amniotomy. Most patients found injections of narcotic agents adequate analgesia in labour. Those patients who did not receive adequate analgesia were principally those who had either very short or quite long labours. Patients with long labours may benefit from more liberal use of analgesia, but no satisfactory form of analgesia seems to be available for patients who are likely to deliver within two or three hours of induction.     

Clinical evaluation of endocervical prostaglandin E2-triacetin-gel for preinduction cervical softening in pregnant women at term

In an open randomized clinical trial 100 pregnant women with low Bishop Scores at term were treated either with intracervical Prostaglandin (PG) E₂ (0.5 mg in 2.5 ml triacetin-gel) 12 hours before labor induction with intravenous oxytocin or with oxytocin infusion alone. In 46 of the 50 pretreated patients (92 %) the Bishop Score progressed at least 3 points, in four cases only 2 points. The mean Bishop score in the untreated patients increased insignificantly. After PGE₂-gel administration 16 patients delivered during the 12 hour interval compared to 3 in the group without pretreatment. The first induction attempt was successful in 14 (64 %) of the 22 patients that were left to be induced after cervical softening and in 26 (57 %) of the 47 women without cervical priming. The Cesarean section rate was 10% (n=5) in the PGE₂-gel group and 12% (_n=6) in the control group. Dosage of oxytocin required for labor induction was significantly lower after cervical softening. No serious fetal or maternal side effects were observed after PGE₂ pretreatment.     

Comparison of intravenous oxytocin and prostaglandin E2 for accelerating labour.

In a prospective study of 52 consecutive women who required acceleration of labour intravenous prostaglandin E2 (PGE2) was used as the oxytocic agent. These mothers were matched for age, parity, height, gestational age, initial cervical dilatation, and station and position of the fetal head with 52 women whose labours were accelerated with oxytocin; both drugs were equally effective. Acceleration to delivery intervals, second-stage durations, the number of assisted deliveries, and Apgar scores were similar regardless of the oxytocic used. Although PGE2 compares well with oxytocin, it offers no further advantages and is more expensive and less well tried than oxytocin.     

Influence of simultaneous low amniotomy and oxytocin infusion and other maternal factors on neonatal jaundice: a prospective study.

In a prospective study of 196 consecutive single births a significant increase in serum bilirubin concentrations was found in infants born after low amniotomy induction and oxytocin infusion compared with those born spontaneously. This relationship was not dose-dependent and may have been associated with artificial interruption of pregnancy rather than the oxytocin itself. Infants delivered after spontaneous labour accelerated by oxytocin showed no such increase. The hormonal surge at the spontaneous onset of labour may affect fetal enzyme induction, but other factors, such as methods of infant feeding and oral contraceptive use, were found not to be significant.     

Comparison of natural and synthetic prostaglandin E2 tablets in labour induction.

A multicentre, randomized, double-blind trial compared the efficacy and safety of and tolerance to natural and synthetically produced prostaglandin E2 tablets in the induction of labour in 202 women. The compounds were similarly effective, inducing labour in approximately 66% of patients. The total dose required and the interval between induction and delivery were similar in the two groups, as were the Apgar scores at 1 and 5 minutes and the incidence of maternal and fetal side effects.     

COOK双球囊导管在足月妊娠引产中的临床研究

目的:探讨宫颈双球囊导管在足月妊娠促宫颈成熟及引产中的有效性和安全性。方法:回顾性选择符合有引产指征、单胎头位、宫颈评分6分的100例足月妊娠孕妇进行分析,其中51例采用COOK双球囊导管引产者为COOK组,49例采用小剂量缩宫素引产者为对照组,比较分析两组宫颈成熟度、引产效果、分娩方式、分娩结局、产后出血、新生儿窒息等情况。结果:100例孕妇引产指征主要是延期(过期)妊娠、羊水过少、妊娠期高血压、妊娠期糖尿病、妊娠合并甲减等。COOK组51例促宫颈成熟有效49例(96.08%),对照组有效16例(32.65%),COOK组促宫颈成熟有效率显著高于对照组,差异有统计学意义(P0.05)。COOK组诱发临产时间明显少于对照组,两组差异有统计学意义(P0.05)。COOK组阴道分娩41例(80.39%),剖宫产10例(19.61%);对照组阴道分娩20例(40.82%),剖宫产29例(59.18%),COOK组阴道分娩率明显高于对照组,剖宫产率明显低于对照组,两组差异均有统计学意义(P0.05)。两组之间的总产程、羊水污染率、新生儿窒息率、产后出血率等围产结局无显著差异(P0.05);COOK组引产过程中出现不良反应6例(11.76%),对照组5例(10.20%),两组无显著差异(P0.05)。结论:COOK双球囊导管促宫颈成熟及引产效果明显优于缩宫素,且不增加不良反应的发生,由于操作简单,有效性和安全性高,值得国内临床推广。