Labor induced using methods that do not involve oxytocin

Intracervical prostaglandins for induction of labour

BACKGROUND

Prostaglandins have been used for cervical ripening and induction of labour since the 1970s. The goal of the administration of prostaglandins in the process of induction of labour is to achieve cervical ripening before the onset of contractions. One of the routes of administration that was proposed is intracervical. Using this route, prostaglandins are less easy to administer and the need for exposing the cervix may cause discomfort to the woman.

OBJECTIVES

To determine the effects of intracervical prostaglandins for third trimester cervical ripening or induction of labour compared with placebo/no treatment and with vaginal prostaglandins (except misoprostol).

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (August 2007) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing intracervical prostaglandins 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 (vaginal prostaglandins, except misoprostol).

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

Fifty-six trials (7738 women) are included. INTRACERVICAL PGE2 WITH PLACEBO/NO TREATMENT: 28 TRIALS, 3764 WOMEN: Four studies reported the number of women who did not achieve vaginal delivery within 24 hours, showing a decreased risk with PGE2 (relative risk (RR) 0.61; 95% confidence interval (CI) 0.47 to 0.79). There was a small, and statistically non-significant, reduction of the risk of caesarean section when PGE2 was used (RR 0.88; 95% CI 0.77 to 1.00). The finding was statistically significant in a subgroup of women with intact membranes and unfavourable cervix only (RR 0.82; 95% CI 0.68 to 0.98). The risk of hyperstimulation with fetal heart rate (FHR) changes was not significantly increased (RR 1.21; 95% CI 0.72 to 2.05). However, the risk of hyperstimulation without FHR changes was significantly increased (RR 1.59; 95% CI 1.09 to 2.33. INTRACERVICAL PGE2 WITH INTRAVAGINAL PGE2: 29 TRIALS, 3881 WOMEN: The risk of not achieving vaginal delivery within 24 hours was increased with intracervical PGE2 (RR 1.26; 95% CI 1.12 to 1.41). There was no change in the risk of caesarean section (RR 1.07; 95% CI 0.93 to 1.22). The risks of hyperstimulation with FHR changes (RR 0.76; 95% CI 0.39 to 1.49) and without FHR changes (RR 0.80; 95% CI 0.56 to 1.15) were non-significantly different with the two methods of PGE2 administration. Only one trial with small sample size reported on women's views, with no difference between groups. INTRACERVICAL PGE2 LOW DOSE WITH INTRACERVICAL PGE2 HIGH DOSE: TWO TRIALS, 102 WOMEN: The trials are too small to provide any useful information.

AUTHORS' CONCLUSIONS

Intracervical prostaglandins are effective compared to placebo, but appear inferior when compared to intravaginal prostaglandins.

Cervical ripening methods for labor induction

The indication for labor induction has been increasing in the world. It is known that cervical conditions are directly associated to the success of labor induction. Knowledge of cervix anatomy and physiology during pregnancy and of the different methods for cervical ripening is essential for indicating the best cervical ripening method in a given situation, therefore obtaining the best outcomes following labor induction. This is a challenge for obstetricians where not every method is readily available and accessible and C-sections rates are very high as in Brazil. Some methods are discussed in this paper including breast stimulation, membrane stripping, and the use of relaxin, oxytocin, prostaglandins, hyaluronidase, mifepristone, laminaria and Foley catheter.

Drotaverine hydrochloride vs. valethamate bromide in acceleration of labor

OBJECTIVES

To compare the efficacy and safety of drotaverine hydrochloride and valethamate bromide in shortening the duration of labor.

METHODS

In a randomized controlled trial of 150 nulliparous women in established labor with cervical dilation of 4 cm, 50 women were given drotaverine (group I), 50 women were given valethamate (group II) and another 50 women were not given any medication (group III). Duration of labor, mode of delivery, side effects, and neonatal outcome were measured in all cases. Appropriate non-parametric tests and chi(2) tests were used for assessment of statistical significance.

RESULTS

In the three groups, 100%, 96% and 46% women delivered within 6 h, respectively. The injection-to-delivery interval was significantly reduced in the drotaverine group (193.96 min) in contrast to the valethamate group (220.68 min) and control group (412.84 min). The rate of cervical dilation was highest in the drotaverine group (2.04 cm/h) compared with the valethamate bromide group (1.86 cm/h) and control group (1.01 cm/h). There were no major maternal or fetal adverse effects in any group, but minor side effects were more common in the valethamate group.

CONCLUSION

Both intramuscular drotaverine hydrochloride and valethamate bromide are effective in acceleration of labor; however, drotaverine accelerates labor more rapidly and is associated with less side effects.