Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term.
BACKGROUND
Prostaglandins have been used for induction of labour since the 1960s. Initial work focused on prostaglandin F2a as prostaglandin E2 was considered unsuitable for a number of reasons. With the development of alternative routes of administration, comparisons were made between various formulations of vaginal prostaglandins.


OBJECTIVE
To determine the effects of vaginal prostaglandins E2 and F2a for third trimester cervical ripening or induction of labour in comparison with placebo/no treatment or other vaginal prostaglandins (except misoprostol).


METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2009) and bibliographies of relevant papers.


METHODS
Clinical trials comparing vaginal 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.


METHODS
We assessed studies and extracted data independently.


RESULTS
Sixty-three (10,441 women) have been included.Vaginal prostaglandin E2 compared with placebo or no treatment reduced the likelihood of vaginal delivery not being achieved within 24 hours (18.1% versus 98.9%, risk ratio (RR) 0.19, 95% confidence interval (CI) 0.14 to 0.25, two trials, 384 women). The risk of the cervix remaining unfavourable or unchanged was reduced (21.6% versus 40.3%, RR 0.46, 95% CI 0.35 to 0.62, five trials, 467 women); and the risk of oxytocin augmentation reduced (35.1% versus 43.8%, RR 0.83, 95% CI 0.73 to 0.94, 12 trials, 1321 women) when PGE2 was compared to placebo. There was no evidence of a difference between caesarean section rates, although the risk of uterine hyperstimulation with fetal heart rate changes was increased (4.4% versus 0.49%, RR 4.14, 95% CI 1.93 to 8.90, 14 trials, 1259 women).PGE2 tablet, gel and pessary appear to be as efficacious as each other and the use of sustained release PGE2 inserts appear to be associated with a reduction in instrumental vaginal delivery rates (9.9 % versus 19.5%, RR 0.51, 95% CI 0.35 to 0.76, NNT 10 (6.7 to 24.0), five trials, 661 women) when compared to vaginal PGE2 gel or tablet.


CONCLUSIONS
PGE2 increases successful vaginal delivery rates in 24 hours and cervical favourability with no increase in operative delivery rates. Sustained release vaginal PGE2 is superior to vaginal PGE2 gel with respect to some outcomes studied.Further research is needed to assess the best vehicle for delivering vaginal prostaglandins and this should, where possible, include some examination of the cost-analysis.
Kelly
Anthony J
AJ
Department of Obstetrics and Gynaecology, Brighton and Sussex University Hospitals NHS Trust, Royal Sussex County Hospital, Eastern Road, Brighton, UK, BN2 5BE.
Malik
Sidra
S
Smith
Lee
L
Kavanagh
Josephine
J
Thomas
Jane
J
D000282:Administration, Intravaginal; D015237:Dinoprost / Q000008:administration & dosage*; D015232:Dinoprostone / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007751:Labor, Induced / Q000379:methods*; D010120:Oxytocics / Q000008:administration & dosage*; D011247:Pregnancy; D047929:Term Birth
D010120:Oxytocics; D015237:Dinoprost; D015232:Dinoprostone