Amniotomy in labor. Dysfunctional labour: a randomised trial. The effect of amniotomy on the outcome of spontaneous labour in uncomplicated pregnancy. Effect of amniotomy upon labor. A controlled study. Spontaneous labour: when should the membranes be ruptured? A trial of amniotomy in a Palestinian hospital. Randomized trial of amniotomy in labour versus the intention to leave membranes intact until the second stage. Influence of spasmolytic treatment and amniotomy on delivery times: a factorial clinical trial. Randomised trial comparing a policy of early with selective amniotomy in uncomplicated labour at term. Effect of early amniotomy on the risk of dystocia in nulliparous women. The Canadian Early Amniotomy Study Group. A randomized controlled trial of early amniotomy. The influence of elective amniotomy on fetal heart rate patterns and the course of labor in term patients: a randomized study. Amniotomy during the active phase of labor.
nan Sixty-one women making slow progress in the active phase of spontaneous labour with intact membranes were randomised to oxytocin and amniotomy, amniotomy only or expectant management. The data show that oxytocin significantly increases the rate of cervical dilatation and shortens prolonged labour, when compared with amniotomy alone and expectant management (P = 0.0144 and 0.0006, respectively). The impact on the operative delivery rate and neonatal outcome is difficult to assess due to the small number of relevant adverse outcomes. Women reported higher satisfaction score in the two groups where intervention followed the diagnosis of dysfunctional labour. The objective of this study is to determine the effect of amniotomy on the outcome of spontaneous labour in uncomplicated pregnancy. A prospective randomised study of low-risk parous women with spontaneous onset of labour at term with singleton fetus in cephalic presentation and intact amniotic membranes and a cervical dilatation between 4 and 5 cm were randomly assigned to have amniotomy (Case) or no amniotomy (Control) during the course of labour. Maternal demographics, labour-delivery data and newborn outcome were compared. A total of 128 women were studied. The duration of labour was significantly shorter in the amniotomy group than the control group (208 vs 292 min; p < 0.05) with the only difference being in the first stage of labour. There was however no difference on the oxytocin requirement for labour augmentation, caesarean section rate, incidence of suspected fetal distress or instrumental delivery in both groups. Newborn outcome measured by Apgar scores at 1 and 5 min showed no significant difference. In conclusion, amniotomy significantly reduced the duration of the first stage of labour without affecting the oxytocin requirement, the rate of caesarean section and newborn outcome. nan Sixty-eight patients (32 multigravidae, 36 primigravidae) with intact membranes admitted in early spontaneous labour were studied. Patients were randomly allocated to two groups: group I had an immediate amniotomy and group II were allowed to retain their membranes intact until full dilatation. Early amniotomy significantly shortened the length of labour and reduced the need for augmentation and instrumental delivery. There were no differences between the two groups in fetal outcome as measured by Apgar scores, umbilical arterial and venous blood pH, neonatal jaundice or admission to the special-care baby unit. Fetal heart-rate recordings obtained in group I by applying a fetal electrode after amniotomy were of superior quality to those obtained in group II by ultrasound and were more suitable for interpretation. 'Normal' and 'suspicious' tracings occurred equally in the two groups. Our results suggest some benefits from early amniotomy and no adverse effects on the fetus. This randomised controlled trial of routine amniotomy was carried out in a developing country setting to investigate the effect of this common procedure on the duration of labour, intra-partum interventions and selected newborn and maternal outcomes. In a Jerusalem teaching hospital, 533 multiparous and 157 nulliparous low-risk women were randomised to either amniotomy or intent to conserve membranes. For multiparae, the median duration from randomisation to full dilatation was 95 and 160 min, respectively in the intervention and control arms (p < 0.001); for nulliparae it was 210 and 270 min, respectively (p < 0.001). In both groups, oxytocin was used less in the intervention arms (p < 0.001), and no difference in mode of delivery and immediate outcomes was detected. However, given the risks of this intervention and these study findings indicating an overall short duration of childbirth, amniotomy should be limited to cases of abnormal progress of labour. To compare by randomized prospective clinical trial the outcome of labours which are managed with the intention to leave the membranes intact, compared with the practice of elective artificial rupture of the membranes (ARM) in early established labour.
                Prospective randomized controlled trial of low risk women admitted in spontaneous labour, with intact membranes.
                The labour ward of St. James's University Hospital, Leeds, UK.
                362 women in spontaneous labour with intact membranes and no evidence of fetal distress, between 37 and 42 weeks gestation. During the course of the trial it was found that some randomization cards could not be accounted for and a system of daily checks was instituted. The results were analysed for all recorded women (n = 362) and after institution of the more rigorous system (n = 120).
                The duration of each phase of labour, epidural rate, prevalence of an abnormal cardiotocograph (CTG) (assessed blind), method of delivery and neonatal outcome.
                178 of the 183 women (97%) in the ARM group had their membranes ruptured in early labour, and 83 (46%) of the 179 women allocated to non-intervention had ARM performed at some stage. A significant decrease in the duration of labour (mean 8.3, SD 4.1 h vs mean 9.7, SD 4.8 h, n = 156; P = 0.05) was found amongst primigravidae allocated to ARM when compared with non intervention. The duration of the second stage of labour was unaffected. In the ARM group the epidural rate was higher and labour was more often complicated by CTG abnormalities. There were no differences in the method of delivery, fetal condition at birth (cord blood lactate, Apgar score) or postpartum pyrexia between the ARM and non-intervention groups. The same trends were observed when analysis was confined to women entered into the trial after the system of rigour was instituted.
                Routine ARM results in labour that is slightly shorter than if the membranes are allowed to rupture spontaneously but more epidurals are used suggesting that labour is more painful. There are fewer fetal heart rate abnormalities if the membranes are left intact but amniotomy has no effect on fetal condition at birth. In a double-blind factorial clinical trial in 300 patients (150 primiparae and 150 multiparae), the effects of amniotomy, rociverine, and butylscopolamine bromide administration on the course of labor were investigated. Rociverine significantly reduced the dilatation time and had no effect on the delivery time. Butylscopolamine bromide had no appreciable effect on the dilatation and expulsion times. Amniotomy resulted in a lengthening of the dilatation time and no significant change in the expulsion time. To compare two management policies: rupture of the fetal membranes when women are in normal labour or leave them intact as long as feasible.
                The labour ward of a city university hospital.
                Automated randomised clinical trial.
                1540 women in uncomplicated term labour. Data on labour duration, blood loss, oxytocin use and fetal condition were collected from 1132 women. Some data from nulliparous women has been presented earlier by the UK Amniotomy Group.
                Duration of labour, Apgar score, fetal morbidity and maternal morbidity including perineal injury, mode of delivery, epidural rates and the total number of vaginal examinations in the first stage of labour after amniotomy.
                Amniotomy at the next vaginal examination or amniotomy only if indicated. The median cervical dilatation at membrane rupture was 2 cm greater in the first group.
                A policy of routine amniotomy in labour had no measurable advantage over selective amniotomy for parous women (difference = 4 min) but shortened labour in nulliparous women by 1 h (Mann-Whitney U test: P < 0.05). There was a suggestion of a higher caesarean section rate (OR 1.9; 95% CI 0.9-3.5), and there were more vaginal examinations after membrane rupture in the group allocated routine amniotomy. There were no measurable differences in oxytocin use, fetal condition at birth, retained placenta rates, blood loss, pain or analgesia requirements.
                Routine amniotomy may shorten the first labour but not subsequent ones. There is a suggestion that routine surgical interference may be harmful by increasing the risk of caesarean section, and this agrees with data from other trials (common odds ratio 1.2; 95% CI 0.92-1.6). Early amniotomy has been advocated as a means of preventing dystocia, but its efficacy has not been studied prospectively. The purpose of this multicenter study was to determine whether routine early amniotomy reduces the risk of dystocia for nulliparous women in spontaneous labor.
                We studied 925 nulliparous women in labor, who were stratified according to the degree of cervical dilatation (< 3 cm vs. > or = 3 cm) and randomly assigned to either early rupture of the membranes (amniotomy group) or conservative management of labor (conservative-management group). Dystocia was defined as a period of at least four hours after dilatation of the cervix to 3 cm had been reached during which the mean rate of cervical dilatation was less than 0.5 cm per hour.
                Dystocia was significantly less frequent in the amniotomy group than in the conservative-management group (34 percent vs. 45 percent; relative risk, 0.8; 95 percent confidence interval, 0.6 to 0.9). The median length of time from randomization to full dilatation was 136 minutes shorter in the amniotomy group, and there was a trend toward less frequent use of oxytocin among the women assigned to amniotomy (36 percent vs. 41 percent; relative risk, 0.9; 95 percent confidence interval, 0.8 to 1.0). In a stratified analysis, the frequency of dystocia associated with amniotomy was reduced only among women with > or = 3 cm initial dilatation. The cesarean-section rate was similar in the two groups (amniotomy, 12 percent; conservative management, 11 percent). There were no statistically significant differences in outcome between the infants delivered by the women in the two groups; the measures of an adverse outcome included admission to a neonatal intensive care unit, five-minute Apgar score below 7, and arterial cord-blood pH below 7.2.
                Early amniotomy is an effective method of shortening the duration of labor and reducing the frequency of dystocia among nulliparous women in labor, but it does not lower the rate of cesarean section. OBJECTIVE-To determine if a policy of early amniotomy resulted in a reduction in mean labour duration when compared to a policy of conservation of the membranes. DESIGN-A single-centre randomized controlled trial. SETTING-A tertiary care teaching hospital in Alberta, Canada. SUBJECTS-Ninety-seven term nulliparae in spontaneous labour, baby in cephalic presentation. INTERVENTION-Early amniotomy versus intent to keep membranes intact. MAIN OUTCOME MEASURES-Interval from randomization to delivery, rate of abnormalities of fetal heart rate tracings, cord artery blood pH, Apgar scores. RESULTS-The mean interval from randomization to delivery was 390.9 (SE 29.1) min in the amniotomy group and 442.9 (SE 34.1) min in the control group (P = 0.251). There were no differences between groups in the occurrence of fetal heart rate tracing abnormalities, nor was there a difference in the proportion of babies with abnormal Apgar scores, or abnormal cord pH (less than 7.20). CONCLUSION-The results of the study fail to support the long held belief that early amniotomy is an effective method for reducing labour duration. Our study was designed to evaluate the effects of routine elective amniotomy on the frequency and severity of abnormal fetal heart rate patterns and on the course of labor and the need for oxytocin augmentation.
                A randomized, controlled trial was conducted at term in patients in active labor who were randomly selected to undergo elective amniotomy (amniotomy group) or left intact with amniotomy reserved for specific indications (intact group).
                Four hundred fifty-nine patients were studied (235 in the amniotomy group vs 224 in the intact group). Average cervical dilatation at rupture was 5.5 cm in the amniotomy group and 8.1 cm in the intact group. Analysis of fetal heart rate revealed more mild and moderate variable decelerations in the active phase of labor in the amniotomy group but no difference in the frequency of more severe decelerations or operative deliveries. In the intact group the need for oxytocin was twice as common (76 in the intact group vs 36 in the amniotomy group, p = 0.000005), and the active phase of labor was considerably longer (5 hours 56 minutes in the intact group vs 4 hours 35 minutes in the amniotomy group). Neonatal outcome was similar in the two groups.
                Elective amniotomy appears to increase the likelihood of umbilical cord compression in the active phase of labor and results in more mild and moderate variable decelerations, but it does not result in more severe abnormal fetal heart rate patterns or more operative intervention. Elective amniotomy does, however, shorten the active phase of labor and decreases the need for oxytocin augmentation. nan
On the basis of the findings of this review, we cannot recommend that amniotomy should be introduced routinely as part of standard labour management and care. We recommend that the evidence presented in this review should be made available to women offered an amniotomy and may be useful as a foundation for discussion and any resulting decisions made between women and their caregivers.