Outcome following a third dose of vaginal prostaglandin tablets (dinoprostone 3mg) for induction of labour.
Dr Lucy Michie (ST2 Obstetrics and Gynaecology), Dr Fiona Mackenzie (Consultant Obstetrician PrincessRoyalMaternityHospital)
Introduction:
The NICE Guideline for Induction of Labour (June 2001) recommended that when induction of labour (IOL) is undertaken with vaginal PGE2 preparations vaginal tablets should be considered in preference to gel formulations (Grade A). The recommended regimen is 3milligramsPGE2tablets 6-8 hourly with a maximum dose of. 6mg.The guideline makes no suggestion regarding the further management of the women whose cervix remains unfavourable for membrane rupture after these two doses. Our practice at Princess Royal Maternity has been to consider a further 3mg PGE2 tablet in these women.Given that this management is outwith the NICE recommendations we reviewed the pregnancy outcomes in this group of women.
Methods:
A retrospective review of all women who received a third 3mg PGE2 tablet for induction of labour between January 2005 and December 2006 was undertaken. Cases were identified from the electronic delivery database.
All casenotes were reviewed and data obtained using a structured proforma. The data obtained included age and parity of patient, gestation at time of IOL, indication for IOL, cervical features documented at time of vaginal tablet administration, grade of doctor examining patient prior to decision for third dose of PGE2,any documented discussion with an Obstetric Consultant and themode of delivery.
Results:
Of the 1149 women who were induced with vaginal PGE2 tablets over the study period 100 received 3 x 3mg PGE2 tablets.
The mean gestational age at IOL was 40-41 weeks and the commonest indication documented was ‘post-dates’ (48%).Cervical assessment prior to administration of a third dose PGE2 was performed by a middle-grade or above in 97% of cases. The Bishop score was only documented prior to insertion of a third dose of PGE2 in 40% of cases and the decision to administer a third dose was discussed with a consultant in 46%.In only 1 woman was it not possible to perform an ARM after 3 doses of PGE2.
The mode of delivery is documented in the table below.
Primigravid n = 83 / Parous n = 17Caesarean section / 45 / 4
SVD / 21 / 13
Assisted vaginal delivery / 17 / 0
The overall Caesarean section rate was 49% in this group of women – 54% for primigravid women and 24% for parous women. This compares with a section rate of 27% for all women undergoing IOL with prostaglandins during the study period (35% for prims and 16% for parous).
Conclusions:
The delivery outcomes for those women receiving a third 3mg dose of PGE2 show that just over 50% of these women achieve a vaginal delivery. The actual figures could allow more accurate counselling in the decision-making process during induction of labour.