What are the guidelines for using dinoprostone (prostaglandin E2) for cervical ripening and labor induction in a pregnant woman at or near term, particularly those with a history of previous uterine surgery, asthma, or glaucoma?

Guidelines for Dinoprostone Use in Labor Induction

Primary Indication

Dinoprostone is indicated for cervical ripening in pregnant women at or near term with an unfavorable cervix (Bishop score <5) when there is a medical or obstetrical indication for labor induction, provided there are no absolute contraindications. 1, 2

Absolute Contraindications

Dinoprostone must not be used in the following situations:

Cardiovascular Contraindications

• Active cardiovascular disease is an absolute contraindication due to profound blood pressure effects, theoretical risk of coronary vasospasm, and low but real risk of arrhythmias 3, 1, 4
• Severe aortic stenosis, pulmonary hypertension, or cyanotic heart disease 4
• In cardiac patients, mechanical methods (Foley catheter) are strongly preferred over dinoprostone 3, 5

Uterine and Obstetric Contraindications (FDA Label)

• History of previous cesarean section or other uterine surgery (such as myomectomy) 2
• Known hypersensitivity to prostaglandins 2
• Evidence or clinical suspicion of fetal distress where delivery is not imminent 2
• Unexplained vaginal bleeding in current pregnancy 2
• Evidence or clinical suspicion of marked cephalopelvic disproportion 2
• Six or more previous term pregnancies 2
• Concurrent use with intravenous oxytocic agents 2
• Any contraindication to induction of labor 2
• Conditions where prolonged uterine contraction may be detrimental to fetal safety 2

Special Populations

History of Glaucoma

• Consider non-prostaglandin cervical ripening procedures (mechanical methods preferred) 2

Asthma

• Prostaglandin E2 has not been associated with worsening lung function or asthma exacerbation 5
• Can be used with appropriate monitoring 5

Dosing and Administration Protocol

Preparation and Insertion

• Administer a single vaginal insert containing 10 mg dinoprostone 2, 6
• The insert releases approximately 0.3 mg/hour 1, 2
• Insert into the posterior vaginal fornix 2
• Patient should remain recumbent for 2 hours after insertion 7

Duration and Removal

• Maximum duration: 12 hours 1, 2
• Remove immediately upon onset of active labor 2
• Remove at 12 hours even if labor has not commenced 2
• The retrieval system facilitates easy removal 6

Transition to Oxytocin

• Wait at least 30 minutes after removing dinoprostone before starting oxytocin 1, 2
• Never use dinoprostone concurrently with intravenous oxytocic agents 2

Mandatory Monitoring Requirements

Continuous monitoring is required throughout dinoprostone administration:

• Continuous fetal heart rate monitoring 1, 5
• Continuous uterine activity monitoring 1, 5
• Careful monitoring of cervical dilatation and effacement progression 2
• Monitor for uterine tachysystole/hyperstimulation (remove insert immediately if occurs) 2, 6

Setting Requirements

• Must be administered only by trained obstetrical personnel 2
• Must be in a hospital setting with appropriate obstetrical care facilities 2
• High-risk patients should deliver in tertiary centers with specialist multidisciplinary team care 3

Comparison with Alternative Agents

When Dinoprostone is NOT Preferred

• Oral misoprostol (20-25 µg every 2-6 hours) results in fewer cesarean sections (RR 0.84) and costs significantly less than dinoprostone 1, 4
• Misoprostol is stable at room temperature while dinoprostone requires refrigeration 4
• However, misoprostol is absolutely contraindicated in women with prior cesarean delivery (13% uterine rupture risk vs. 2% with dinoprostone) 5

When Mechanical Methods are Preferred

• Patients with cyanosis where drops in systemic vascular resistance would be detrimental 3, 5
• Active cardiovascular disease 3, 5
• Prior cesarean delivery (mechanical methods safer than any prostaglandin) 5

Critical Safety Warnings

Uterine Hyperstimulation

• Dinoprostone carries risk of uterine tachysystole and hyperstimulation 2, 6
• This is rapidly reversible upon removal of the insert 6
• Remove insert immediately if hyperstimulation occurs 2

Rare but Serious Complications

• Disseminated intravascular coagulation: assess for evolving fibrinolysis in immediate postpartum period 2
• Amniotic fluid embolism syndrome: monitor for hypotension, hypoxemia, respiratory failure, DIC, coma or seizures 2

Common Pitfalls to Avoid

• Never use in women with prior cesarean delivery - this is an FDA contraindication despite some research suggesting it may be used with caution 2, 8
• Never use concurrently with oxytocin - wait at least 30 minutes after removal 2
• Avoid prolonged induction time when cervix remains unfavorable - consider alternative methods 3, 5
• Do not use in active cardiovascular disease - choose mechanical methods instead 3, 4
• Ensure continuous monitoring is maintained throughout administration 1, 2