A comparison of early and delayed induction of labor with spontaneous rupture of membranes at term

The management of women with spontaneous rupture of membranes at term in the absence of labor and with a cervix unfavorable for induction of labor is controversial. In this randomized study of 182 patients, we report the effects of delayed versus early induction of labor on maternal and neonatal outcome. Qualifying patients not in labor at 6 hours after spontaneous rupture of membranes were randomized to either immediate oxytocin induction (86 women) or expectant management with oxytocin induction at 24 hours if labor had not occurred spontaneously (96 women). The cesarean section rate did not differ between the two groups. Women in the delayed group had significantly longer hospitalization (P less than .003), and their infants were significantly more likely to receive antibiotics (P = .006). Infectious morbidity (positive cultures or x-ray-documented pneumonia) occurred in five of the neonates in the delayed group, all of whose mothers had an initial digital cervical examination, but in none of the neonates in the early group, a difference that did not reach statistical significance (P = .061). Five (28%) of 18 infants from the delayed group whose mothers had received an initial digital cervical examination became infected, compared with none of the 78 infants from the delayed group whose mothers did not have digital examinations (P less than .001). We conclude that there is no advantage to delaying induction of labor when women present at term with spontaneous rupture of membranes.     

Predictors for prolonged interval from premature rupture of membranes to spontaneous onset of labor at term

Objective: To identify predictors for prolonged interval from premature rupture of membranes (PROM) to spontaneous onset of labor in women presenting with PROM and low Bishop score at term.

Methods: A retrospective study of women presenting with PROM and Bishop score?Results: Among 625 women who met inclusion criteria, 155 (24.8%) had a prolonged interval to onset of labor. In multivariate analysis, prolonged PROM was associated with (OR, 95%CI) cervical dilatation (0.35, 0.24–0.52, p?p?p?=?0.004). A multivariable prediction model including maternal age, parity, cervical dilatation and effacement, gestational age and neonatal birthweight was associated with an AUC of receiver–operator characteristic curve of 0.739 (0.631–0.847, p?Conclusion: Uterine contractions and cervical examination parameters can be used for prediction of prolonged interval to spontaneous onset of labor in women with term PROM.     

Management of premature rupture of membranes at term.

Although prelabor rupture of membranes at term is common, in most cases, the spontaneous onset of labor relieves the obstetrician of the need for making management decisions. The standard practice in the United States has been to induce labor with intravenous oxytocin in that minority of patients who fail to labor spontaneously. Controlled trials suggest that this practice is associated with higher rates of both chorioamnionitis and the need for cesarean delivery than is expectancy. Expectancy, however, has not been demonstrated to be safer for the perinate.     

Zinc status in women with premature rupture of membranes at term

Zinc concentrations were measured by atomic absorption spectrometry in whole blood, scalp hair, pubic hair, and colostrum from patients at term with and without premature rupture of membranes (PROM). A maternal zinc index was established for each patient, expressed as an average ranking of the four determinations. The mean +/- SD value of the maternal zinc index in patients with PROM was significantly lower than in patients without this complication (4.33 +/- 1.18 versus 5.97 +/- 1.39, respectively; P = .0002). The inverse relationship between maternal zinc index and parity was statistically significant (r = -0.61; P = .04). These results suggest that the subnormal tissue zinc content in pregnancy may play a role as a causative factor in PROM at term.     

24 hour rhythm in the timing of pre-labour spontaneous rupture of membranes at term

OBJECTIVE: To study the timing of pre-labour spontaneous rupture of membranes (SROM) in term pregnancies. DESIGN: Prospective cohort. SETTING: A maternity hospital in the United Kingdom. SAMPLE: Women who were more than 37 weeks gestation with confirmed spontaneous rupture of membranes and not in labour after 4 h. METHODS: Women who were admitted into labour ward with a diagnosis of spontaneous rupture of membranes after 37 weeks of gestation were included. The women's demographic details were recorded and inquiries about whether they had sexual intercourse in the preceding 12 h. The final outcome of their pregnancy was recorded and analysed. MAIN OUTCOME MEASURES: (1) The exact time of spontaneous rupture of membranes, (2) the time of onset of spontaneous labour, (3) delivery details. RESULTS: One hundred and ninety-six women were studied. A 24 h rhythm in the timing of spontaneous rupture of membranes was found with 33.2% occurring between 00:00 and 04:00 h. When contractions representing the onset of labour occurred there was no diurnal rhythm to the timing of onset of contractions. CONCLUSIONS: There is a 24 h rhythm in the timing of spontaneous rupture of membranes in term gestations. The physiological reasons for this rhythm are not understood at the present time.     

Misoprostol for labor induction in women with term premature rupture of membranes: a meta-analysis

OBJECTIVE: To systematically review published data evaluating the comparative use of misoprostol with placebo/expectant management or oxytocin for labor induction in women with term (> or = 36 weeks of gestation) premature rupture of membranes. DATA SOURCES: PubMed (1966-2005), Ovid (1966-2005), CINAHL, The Cochrane Library, ACP Journal Club, OCLC, abstracts from scientific forums, and bibliographies of published articles were searched using the following keywords: premature rupture of membranes, misoprostol, labor induction, and cervical ripening. Primary authors were contacted directly if the data sought were unavailable or only published in abstract form. METHODS OF STUDY SELECTION: Only randomized controlled trials evaluating the efficacy and safety of misoprostol in comparison with placebo or expectant management (n = 6) and oxytocin (n = 9) published in either article or abstract form were analyzed and included in the meta-analysis. TABULATION, INTEGRATION, AND RESULTS: Studies were reviewed independently by all authors. Meta-analysis was performed, and the relative risks (RRs) were calculated and pooled for each study outcome. Misoprostol, compared with placebo, significantly increased vaginal delivery less than 12 hours (RR 2.71, 95% confidence interval [CI] 1.87-3.92, P < .001). Misoprostol was similar to oxytocin with respect to vaginal delivery less than 24 hours (RR 1.07, 95% CI 0.88-1.31, P = .50) and less than 12 hours (RR 0.98, 95% CI 0.71-1.35, P = .90). Misoprostol was not associated with an increased risk of tachysystole, hypertonus, or hyperstimulation syndrome when compared with oxytocin and had similar risks for adverse neonatal and maternal outcomes. CONCLUSION: Misoprostol is an effective and safe agent for induction of labor in women with term premature rupture of membranes. When compared with oxytocin, the risk of contraction abnormalities and the rate of maternal and neonatal complications were similar among the 2 groups.     

Uterine tachysystole in spontaneous labor at term

Objectives: The objective of this study is to determine the incidence of uterine tachysystole and its association with spontaneous labor at term.

Methods: A retrospective cohort study of 8008 women in spontaneous labor (without prostaglandins or oxytocin). Fetal heart tracings and uterine activity were recorded every 15?min. Primary outcome: occurrence of tachysystole (> 5 uterine contractions /10?min over 30?min periods). Secondary outcomes: non-reassuring fetal heart tracings (NRFHT), NICU admissions, and cesarean deliveries.

Results: About 890 patients (11.1 %) had at least one episode of tachysystole. Non-whites have higher incidence of uterine tachysystole; adjusted odds ratio (aOR) was 1.66 for Hispanics (95% CI 1.28–2.05), 1.58 for African Americans (95% CI 1.05–2.38), and 1.51 for Asians (95% CI?=?1.13–2.0). The use of epidural analgesia was higher in the tachysystole group (62.2% versus 40.9%, aOR 1.89, CI 1.58–2.26; p?< 0.001). Tachysystole was more frequent among nulliparous women and in women carrying higher weight fetuses. Oligohydramnios (aOR 1.62, CI 0.70–3.72; p?<?0.004), and NRFHT were more common in the tachysystole group (4.2% versus 2.5%, p?=?0.002). Newborns in the tachysystole group were two times more likely to be admitted to NICU (30 /890 [3.4%] versus 122 /7118 [1.7%], OR?=?2, p=0.001). There was no difference in the frequency of meconium-stained amniotic fluid or Apgar scores <7 at 5?min.

Conclusion: Uterine tachysystole occurs in more than 10% of spontaneous labors and is associated with NRFHR, increased rate of caesarean deliveries and NICU admissions. It is not associated with low Apgar scores or meconium-stained amniotic fluid.     

Premature rupture of membranes at term in nulliparous women: a hazard?

One hundred five consecutive women with premature rupture of the membranes (PROM) at term were managed expectantly for at least 24 hours. Seventy-six went into spontaneous labor, of whom 38 were augmented with oxytocin. Twenty-nine had labor induced. Subjects who delivered during the same study interval after artificial rupture of the membranes served as controls. There were no statistically significant differences in the frequency of amnionitis, endometritis, cystitis, neonatal infection, low Apgar score, low cord arterial blood pH, instrumental delivery, or cesarean delivery. Morbidity was seen most often in induced labor whether or not the membranes were ruptured for a long time. It is concluded that expectant management of PROM at term does not increase perinatal morbidity.     

A study of 579 pregnant women with premature rupture of membranes at term

Objective

To determine the best management for women with premature rupture of membranes at term.

Method

In 2008, 579 women admitted to Peking University First Hospital for premature rupture of membranes (PROM) at term were allocated to one of 3 groups. Group 1 (n = 292) consisted of those whose labor began spontaneously within 12 hours of PROM; group 2 (n = 234), of those whose labor did not begin within 12 hours of PROM and were induced with oxytocin; and group 3 (n = 53), of those who accepted a cesarean delivery immediately after PROM was diagnosed. The χ² test was used to compare the rates of intrauterine and neonatal infection in these 3 groups.

Results

Compared with the intrauterine and neonatal infection rates for group 1 (3.4% and 13.7%) and group 3 (1.9% and 3.8%), the corresponding rates were higher for group 2 (10.7% and 21.8%) (P < 0.05). In group 2, 76.5% of the women began labor within 24 hours of induction and 92.7% of these within 12 hours.

Conclusion

In women at term, induction should be performed immediately after PROM is diagnosed, as it is likely to fail when labor does not begin within 12 hours of oxytocin administration.     

Comparative study of induction of labor in nulliparous women with premature rupture of membranes at term compared to those with intact membranes: duration of labor and mode of delivery

AIM: To evaluate the effect of premature rupture of membranes (PROM) at term on the duration of labor and mode of delivery in comparison with intact membranes in nulliparous women with an unfavorable cervix whose labor was induced. METHODS: This retrospective cohort study included all term nulliparous women with an unfavorable cervix requiring labor induction over a 2-year period. Prostaglandin E(2) (dinoprostone) and oxytocin were used for labor induction. Criteria for enrolment included (i) singleton pregnancy; (ii) term nulliparous women; or (iii) Bishop score below 6. Statistics were analyzed with Student's t-test, chi(2)-test, Fisher's exact test, and multiple logistic regression. RESULTS: Our study subjects were 82 women whose labor was induced for PROM and 219 women with intact membranes whose labor was induced for social or fetal reasons. The mean durations of active phase of labor were not significantly different between women with PROM and those with intact membranes. However, the women with PROM had a significantly longer mean duration of second stage and a higher rate of cesarean delivery for failure to progress than those with intact membranes. Multiple logistic regression demonstrated that only PROM and fetal macrosomia were significantly associated with an increased risk of cesarean delivery for failure to progress after other confounding variables were adjusted. CONCLUSIONS: Labor induction for PROM at term in nulliparous women with an unfavorable cervix is associated with longer duration of the second stage and a higher risk of cesarean delivery for failure to progress in comparison to those with intact membranes.     

Amniotic fluid interleukin-1 in spontaneous labor at term

The regulatory signals responsible for the increased biosynthesis of prostaglandins during parturition have not been established. Interleukin-1 (IL-1) is capable of stimulating prostaglandin production by intrauterine tissues and is an inflammation mediator. It has been postulated as a signal for the onset of labor in the setting of intrauterine infection. A study was designed to determine if spontaneous labor at term was associated with changes in IL-1 activity in amniotic fluid. Such fluid was retrieved from 41 women in labor and from 39 women who were not in labor at term. Immunodetectable IL-1 beta was present in 22 of the 41 women in labor but in only 8 of the 39 women without labor. IL-1-like bioactivity was not different between the two groups at a dilution of 1:4, but at dilutions of 1:12, 1:36 and 1:108, amniotic fluid from women in labor had significantly higher bioactivity than that from women not in labor. A significant correlation was found between the bioassay and immunoassay results. Our data show that inhibitors of IL-1 bioactivity are present in amniotic fluid and suggest that in a subset of laboring women at term, an inflammatory reaction may play a role in triggering the onset of parturition.     

Graphic analysis of actively managed labor: prospective computation of labor progress in 500 consecutive nulliparous women in spontaneous labor at term

OBJECTIVE: Active management has been shown to shorten the length of labor and reduce the incidence of prolonged labor. We examined the influence of this protocol on the rate of cervical dilatation by calculating a mean partogram to explain how this acceleration is achieved. STUDY DESIGN: We retrospectively analyzed partograms of cervical dilation in 500 consecutive nulliparous women in spontaneous labor at term with a singleton fetus in a cephalic presentation; cesarean deliveries were not excluded. Mean cervical dilations at admission and mean time intervals to reach 2, 3, 4, 6, 8, and 10 cm of dilatation and delivery were calculated, with 95% confidence intervals, both for the whole cohort and specifically in women with cervical dilatations <3 cm at admission. These data were used to construct mean partograms. RESULTS: The mean duration of labor was 6.1 hours. The mean cervical dilatation at admission was 1. 7 cm; all but 2.8% were delivered within 12 hours. The cesarean rate was 5.4%. The mean partogram, with narrow 95% confidence intervals, shows a rapid active phase after a much shorter latent phase than reported in other analyses of labor. CONCLUSION: Active management reduces the duration of first labor mainly by shortening the latent phase in association with amniotomy at very early cervical dilatations and does not delay the diagnosis of labor until the active phase has begun.     

Prostaglandin E2 for induction of labor in patients with premature rupture of membranes at term.

OBJECTIVE: A prospective study comparing three management schemes for patients at term with premature rupture of membranes was performed. STUDY DESIGN: One hundred forty patients were randomized to one of three study groups: prostaglandin E2, placebo, or oxytocin. Patients randomized to prostaglandin E2 and placebo received vaginal suppositories containing 3 mg prostaglandin E2 or glycerin only, respectively; suppositories were administered in a double-blind fashion, on one or two occasions, 6 hours apart. Oxytocin was given only if labor was not established after 12 hours or to augment inadequate labor. In patients randomized to oxytocin labor was induced with intravenous oxytocin. The time interval to delivery, delivery outcome, and complications were analyzed. RESULTS: Patients receiving prostaglandin E2 were more likely to be in labor after one suppository and to be delivered without the addition of oxytocin when compared with placebo. The time interval to delivery was shorter with prostaglandin E2 and oxytocin induction versus placebo ("expectant management"). The incidence of maternal infection was lowest in patients with labor induced by prostaglandin E2. Although the overall cesarean section rate was low, there was a trend toward a lower rate with prostaglandin E2 induction. No adverse effects were observed with prostaglandin E2. CONCLUSION: Prostaglandin E2 can be used successfully to induce labor after premature rupture of membranes at term with greater ease of administration when compared with oxytocin.