Australian and New Zealand Journal of Obstetrics and Gynaecology 2014; 54: 586–588
DOI: 10.1111/ajo.12221
Short Communication
The effect of extending dinoprostone pessary placement from 12 to 24 h on the need for further mechanical cervical ripening Vanessa LUSINK,1,* Leila USHER1 and Tania DAY2 1
Department of Obstetrics and Gynaecology, The Maitland Hospital, Maitland, and 2Department of Maternity and Gynaecology, John Hunter Hospital, Newcastle, Australia
Dinoprostone pessaries (DP) are widely used for cervical ripening, and while licensed for 12-h administration in Australia, 24-h use is also reported. We examined 396 consecutive women before and after a protocol change from 12-h to 24-h DP use to determine whether extended DP use decreases the need for additional mechanical cervical ripening. No significant difference in cervical ripening balloon (CRB) requirement or vaginal birth rates was detected, showing that prolonged DP use does not reduce subsequent use of CRB. Key words: cervical dilatation, cervical ripening, dinoprostone, induced labour, intravaginal drug administration.
Introduction
Materials and Methods
Labour is induced in almost 26% of pregnancies, and prostaglandins are used for cervical ripening in the majority of these.1 Cervidilâ (CSL Limited, Melbourne, Victoria, Australia) is a 10 mg dinoprostone pessary (DP) placed intravaginally, releasing prostaglandin E2 at 0.3 mg/h over 24 h.2,3 In Australia, the Therapeutic Goods Administration has licensed Cervidilâ for 12-h use, although publications from Australia, the USA, Canada and Europe describe 24-h use.4–8 Recent Australian data on the safety of 24-h DP use describes no difference in maternal or neonatal morbidities, including intrapartum fever, postpartum haemorrhage, low Apgar score and admission to neonatal intensive care.4 This and other studies demonstrate that the incidence of tachysystole with or without fetal heart rate changes during DP administration is as high as 10%, with 68–95% of cases occurring within the first 12 h of administration.4–6,9–11 Despite multiple reports of 24-h DP use, there is scant data available on the effectiveness of extending the duration of DP placement, particularly on the need for further ripening with a cervical ripening balloon (CRB).
Consecutive women requiring cervical ripening with a DP between July 2012 and September 2013 were included in a retrospective cohort study. The study site was the Maitland Hospital, a level 5 rural referral centre where approximately 1500 women over 34 weeks gestation deliver per year. Formal ethics approval was not sought as this project conforms to the standards established by the NHMRC for ethical quality review.12 Women were identified from a local database, and data were extracted from that and chart review. We estimated that 30% of women require a CRB after insertion of DP for 12 h, and a reduction to 15% with extended duration placement. At least 120 women per group are necessary to demonstrate this difference with an alpha of 0.05 and a power of 80%. Women were included if they received DP per local health service guidelines; candidates include: singleton pregnancies in cephalic presentation, a normal cardiotocograph (CTG) prior to insertion, normal amniotic fluid index (AFI), no uterine scar and a Bishop’s score
DOI: 10.1111/ajo.12221
Short Communication
The effect of extending dinoprostone pessary placement from 12 to 24 h on the need for further mechanical cervical ripening Vanessa LUSINK,1,* Leila USHER1 and Tania DAY2 1
Department of Obstetrics and Gynaecology, The Maitland Hospital, Maitland, and 2Department of Maternity and Gynaecology, John Hunter Hospital, Newcastle, Australia
Dinoprostone pessaries (DP) are widely used for cervical ripening, and while licensed for 12-h administration in Australia, 24-h use is also reported. We examined 396 consecutive women before and after a protocol change from 12-h to 24-h DP use to determine whether extended DP use decreases the need for additional mechanical cervical ripening. No significant difference in cervical ripening balloon (CRB) requirement or vaginal birth rates was detected, showing that prolonged DP use does not reduce subsequent use of CRB. Key words: cervical dilatation, cervical ripening, dinoprostone, induced labour, intravaginal drug administration.
Introduction
Materials and Methods
Labour is induced in almost 26% of pregnancies, and prostaglandins are used for cervical ripening in the majority of these.1 Cervidilâ (CSL Limited, Melbourne, Victoria, Australia) is a 10 mg dinoprostone pessary (DP) placed intravaginally, releasing prostaglandin E2 at 0.3 mg/h over 24 h.2,3 In Australia, the Therapeutic Goods Administration has licensed Cervidilâ for 12-h use, although publications from Australia, the USA, Canada and Europe describe 24-h use.4–8 Recent Australian data on the safety of 24-h DP use describes no difference in maternal or neonatal morbidities, including intrapartum fever, postpartum haemorrhage, low Apgar score and admission to neonatal intensive care.4 This and other studies demonstrate that the incidence of tachysystole with or without fetal heart rate changes during DP administration is as high as 10%, with 68–95% of cases occurring within the first 12 h of administration.4–6,9–11 Despite multiple reports of 24-h DP use, there is scant data available on the effectiveness of extending the duration of DP placement, particularly on the need for further ripening with a cervical ripening balloon (CRB).
Consecutive women requiring cervical ripening with a DP between July 2012 and September 2013 were included in a retrospective cohort study. The study site was the Maitland Hospital, a level 5 rural referral centre where approximately 1500 women over 34 weeks gestation deliver per year. Formal ethics approval was not sought as this project conforms to the standards established by the NHMRC for ethical quality review.12 Women were identified from a local database, and data were extracted from that and chart review. We estimated that 30% of women require a CRB after insertion of DP for 12 h, and a reduction to 15% with extended duration placement. At least 120 women per group are necessary to demonstrate this difference with an alpha of 0.05 and a power of 80%. Women were included if they received DP per local health service guidelines; candidates include: singleton pregnancies in cephalic presentation, a normal cardiotocograph (CTG) prior to insertion, normal amniotic fluid index (AFI), no uterine scar and a Bishop’s score
