Prelabor Rupture of Membranes at Term: Induction Techniques

Preterm and term prelabour rupture of membranes: A review of timing and methods of labour induction

Prelabour rupture of membranes (PROM) exposes both foetuses and mothers to the risk of infection. Induction of labour has been proposed to reduce this risk, but its neonatal and maternal risks and benefits must be balanced against those of expectant management (EM). Recent randomized studies of preterm PROM show that EM until 37 weeks of gestation is associated with lower overall neonatal morbidity. In term PROM, active management is associated with a shorter birth interval but not with lower rates of neonatal infection. Similar maternal and neonatal outcomes are reported regardless of whether induction uses oxytocin, PGE2, or oral misoprostol.

The value of ultrasound measurement of cervical length and parity in prediction of cesarean section risk in term premature rupture of membranes and unfavorable cervix

AIM

To evaluate the influence of cervical length (CL) and parity as prediction factors for assessment of cesarean section (CS) risk in women with premature rupture of membranes (PROM) at term and unfavorable cervix, undergoing induction of labor (IOL) with dinoprostone intracervical gel.

METHODS

A prospective study involved 50 nulliparous and 51 multiparous women admitted for IOL. Pre-induction CL was measured and delivery outcomes were recorded.

RESULTS

Nulliparous women were younger than the multiparous (26.6±5.2 vs. 30.5±4.9; P<0.001) and had longer pre-induction CL (35.6±5.5 vs. 31.5±4.8; P<0.001) and induction-delivery interval (582 vs. 420 min; P<0.001). There was no difference in the mode of delivery, CS indications, Apgar score, neonatal weight, the rate of neonatal intensive care unit admission and perinatal death in respect of parity. CL was significantly shorter in vaginal vs. cesarean deliveries regardless of parity (31.4 vs. 38.8 mm, P<0.001, respectively). Cut-off values of CL for predicting CS were 37.5 mm in nulliparae and 34.5 mm in multiparae.

CONCLUSIONS

CLs of 37.5 mm in nulliparae and 34.5 mm in multiparae were determined as the cut-off values in predicting CS risk in women with PROM at term and unfavorable cervix.

Misoprostol versus prostaglandin E2 gel for labor induction in premature rupture of membranes after 34 weeks of pregnancy

BACKGROUND

Both misoprostol and prostaglandin E2 (PGE2) gel are used for labor induction in women with premature rupture of membranes (PROM).

OBJECTIVES

To evaluate studies comparing the effects of misoprostol and PGE2 gel in labor induction.

SEARCH STRATEGY

Databases including Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched for relevant papers.

SELECTION CRITERIA

Randomized controlled trials comparing the use of misoprostol and PGE2 gel for labor induction in women with PROM were included.

DATA COLLECTION AND ANALYSIS

For meta-analyses, the Mantel-Haenszel method was used for dichotomous data, and the inverse variance method was used for continuous data.

MAIN RESULTS

Four randomized controlled studies (n=615) were included. There were no significant differences between the two groups in the induction-to-delivery interval (mean difference -4.44 hours; 95% confidence interval [CI] -9.35 to 0.48), rate of cesarean delivery (odds ratio [OR] 0.90; 95% CI 0.44-1.85), and rate of neonatal intensive care unit admission (OR 0.89; 95% CI 0.57-1.38). Women receiving misoprostol had a significantly higher rate of tachysystole than did those receiving PGE2 gel (OR 4.84; 95% CI 2.46-9.54).

CONCLUSIONS

Misoprostol is as efficacious and safe as PGE2 gel for labor induction in women with PROM.

Antibiotics for prelabour rupture of membranes at or near term

BACKGROUND

Prelabour rupture of the membranes (PROM) at or near term (defined in this review as 36 weeks' gestation or beyond) increases the risk of infection for the woman and her baby. The routine use of antibiotics for women at the time of term PROM may reduce this risk. However, due to increasing problems with bacterial resistance and the risk of maternal anaphylaxis with antibiotic use, it is important to assess the evidence addressing risks and benefits in order to ensure judicious use of antibiotics. This review was undertaken to assess the balance of risks and benefits to the mother and infant of antibiotic prophylaxis for PROM at or near term.

OBJECTIVES

To assess the effects of antibiotics administered prophylactically to women with PROM at 36 weeks' gestation or beyond, on maternal, fetal and neonatal outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2014).

SELECTION CRITERIA

All randomised trials that compared outcomes for women and infants when antibiotics were administered prophylactically for prelabour rupture of the membranes at or near term, with outcomes for controls (placebo or no antibiotic).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted the data and assessed risk of bias in the included studies. Additional data were received from the investigators of included studies.

MAIN RESULTS

This update includes an additional two studies involving 1801 women, giving a total of four included studies of 2639 women. Whereas the previous version of this review showed a statistically significant reduction in endometritis with the use of antibiotics, no such effect was shown in this update (average risk ratio (RR) 0.34, 95% confidence interval (CI) 0.05 to 2.31). No differences were shown on the primary outcome measures of probable early-onset neonatal sepsis (average RR 0.69, 95%; CI 0.21 to 2.33); definite early-onset neonatal sepsis (average RR 0.57, 95% CI 0.08 to 4.26); maternal infectious morbidity (chorioamnionitis and/or endometritis) (average RR 0.48, 95% CI 0.20 to 1.15); stillbirth (RR 3.00, 95% CI 0.61 to 14.82); and perinatal mortality (RR 1.98, 95% CI 0.60 to 6.55), though the number of cases in the control group for these outcomes was low. There were no cases of neonatal mortality or serious maternal outcome in the studies assessed. Caesarean section was increased with the use of antibiotics (RR 1.33, 95% CI 1.09 to 1.61) as was duration of maternal stay in hospital (mean difference (MD) 0.06 days, 95% CI 0.01 to 0.11), largely owing to one study of 1640 women where repeat caesarean section, increased baseline hypertension and pre-eclampsia were evident in the antibiotic group, despite random allocation and allocation concealment.Subgroup analyses by timing of induction (early induction versus late induction) showed no difference in either probable or definite early-onset neonatal sepsis in the early induction group (RR 1.47, 95% CI 0.80 to 2.70 and RR 1.29, 95% CI 0.48 to 3.44, respectively) or the late induction group (RR 0.14, 95% CI 0.02 to 1.13 and RR 0.16, 95% CI 0.02 to 1.34, respectively), although there were trends toward reduced probable and definite early-onset neonatal sepsis in the late induction group. A test for subgroup differences confirmed a differential effect of the intervention on probable early-onset neonatal sepsis between the subgroups (Chi² = 4.50, df = 1 (P = 0.03), I² = 77.8%). No difference in maternal infectious morbidity (chorioamnionitis and/or endometritis) was found in either subgroup, though again there was a trend towards reduced maternal infectious morbidly in the late induction group (average RR 0.34, 95% CI 0.08 to 1.47). No differences were shown in stillbirth or perinatal mortality. The quality of the evidence for the primary outcomes using GRADE was judged to be low to very low.

AUTHORS' CONCLUSIONS

This updated review demonstrates no convincing evidence of benefit for mothers or neonates from the routine use of antibiotics for PROM at or near term. We are unable to adequately assess the risk of short- and long-term harms from the use of antibiotics due to the unavailability of data. Given the unmeasured potential adverse effects of antibiotic use, the potential for the development of resistant organisms, and the low risk of maternal infection in the control group, the routine use of antibiotics for PROM at or near term in the absence of confirmed maternal infection should be avoided.

Orally administered misoprostol for induction of labor with prelabor rupture of membranes at term

Prelabor rupture of membranes (PROM) occurs in approximately 8% to 10% of women with term pregnancies. The management of PROM continues to be controversial. Approaches include expectant management and immediate induction of labor. The use of orally administered misoprostol for the management of women with PROM may provide significant advantages when they choose immediate induction of labor. This literature review presents current evidence that supports the use of oral misoprostol for women with PROM, including the benefits of a decreased interval time from PROM to vaginal birth, good safety profile, and reductions in the use of oxytocin augmentation and epidural anesthesia. In addition to clinically proven benefits to women of oral misoprostol for PROM, it also has the potential to reduce chorioamnionitis by reducing the number of sterile vaginal examinations performed thereby reducing the risk of ascending bacteria. Women have also reported acceptability and satisfaction when using oral misoprostol for immediate induction of labor. This review of literature discusses what is known about the use of orally administered misoprostol for the management of term PROM and makes recommendations for clinical use.

Antibiotic prophylaxis in prelabor spontaneous rupture of fetal membranes at or beyond 36 weeks of pregnancy

OBJECTIVE

To assess the effectiveness of prophylactic antibiotics compared with placebo in preventing neonatal and maternal infection-related morbidity associated with prelabor spontaneous rupture of membranes at or beyond 36 weeks of pregnancy.

METHODS

In the present randomized controlled trial conducted during 2009-2011, 1640 women with prelabor spontaneous rupture of fetal membranes at or beyond 36 weeks of pregnancy were randomly assigned to receive a single dose of prophylactic intravenous antibiotics or placebo on admission to the labor ward of Ain Shams University, Cairo, Egypt. The participants, caregivers, and investigators were blinded to the group assignment. The primary outcome measure was early-onset neonatal sepsis. An intention-to-treat analysis was performed.

RESULTS

Early-onset neonatal sepsis occurred in 34 (4.1%) and 24 (2.9%) neonates in the antibiotics and placebo groups, respectively (risk ratio 1.42; 95% confidence interval 0.85-2.37). Maternal infection outcomes were not significantly different between the 2 trial arms.

CONCLUSION

The routine use of prophylactic antibiotics in women with prelabor spontaneous rupture of fetal membranes at or beyond 36 weeks of pregnancy does not reduce the risk of neonatal and maternal infection-related morbidity.

Labor induction in term premature rupture of membranes: comparison between oxytocin and dinoprostone followed 6 hours later by oxytocin

OBJECTIVE

The aim of this randomized study was to compare 2 protocols for inducing labor in women with premature rupture of membranes (PROM) at term.

STUDY DESIGN

Women with PROM and a Bishop score ≤5 were randomly assigned to receive either an intravenous oxytocin infusion (n = 223) or a dinoprostone pessary followed 6 hours later by an intravenous oxytocin infusion (n = 227).

RESULTS

Vaginal delivery within 24 hours of labor induction increased significantly with sustained-released dinoprostone followed by oxytocin infusion (78.5% vs 63.3%; relative risk, 1.23; 95% confidence interval, 1.09-1.39; P = .001). Maternal and neonatal outcomes were similar between the groups.

CONCLUSION

Sustained-released dinoprostone followed 6 hours later by an oxytocin infusion in term women with PROM was associated with a higher rate of vaginal delivery within 24 hours, and no difference in maternal-neonatal complications was observed compared with oxytocin infusion alone.