What are the guidelines for administering dinoprostone (prostaglandin E2) gel to a pregnant woman for labor induction, considering her medical history and potential complications?

Guidelines for Dinoprostone Gel Administration

Dosing and Administration Protocol

Administer a single dinoprostone vaginal insert (10 mg) for up to 12 hours, releasing approximately 0.3 mg per hour, and remove upon onset of active labor or after 12 hours. 1

• Dinoprostone must only be administered by trained obstetrical personnel in a hospital setting with appropriate obstetrical care facilities 1
• Carefully monitor uterine activity, fetal status, and progression of cervical dilation and effacement throughout administration 1
• If transitioning to oxytocin, remove the vaginal insert at least 30 minutes before administering any oxytocic agent 1

Absolute Contraindications

Dinoprostone is absolutely contraindicated in women with active cardiovascular disease, previous cesarean section, or any uterine surgery. 2, 1

Cardiovascular Contraindications

• Active cardiovascular disease (profound blood pressure effects, theoretical coronary vasospasm risk, and arrhythmia risk) 2
• Severe aortic stenosis 2
• Pulmonary hypertension 2
• Cyanotic heart disease (where drops in systemic vascular resistance would be detrimental) 2

Obstetric Contraindications

• History of previous cesarean section or uterine surgery such as myomectomy 1
• Known hypersensitivity to prostaglandins 1
• Evidence or clinical suspicion of fetal distress where delivery is not imminent 1
• Unexplained vaginal bleeding in current pregnancy 1
• Evidence or clinical suspicion of marked cephalopelvic disproportion 1
• Any contraindication to induction of labor 1
• Concurrent use with intravenous oxytocic agents 1
• Conditions where prolonged uterine contraction may be detrimental to fetal safety 1
• Six or more previous term pregnancies 1

Critical Safety Monitoring

Uterine Activity Complications

• Monitor continuously for uterine tachysystole (≥6 contractions in 10 minutes for two consecutive 10-minute periods) and uterine hypersystole/hypertonicity 1
• Remove vaginal insert immediately if tachysystole or hypersystole occurs 1
• Uterine tachysystole with or without fetal distress represents the most common adverse reaction (≥2% incidence) 1

Rare but Serious Complications

• Assess for evolving fibrinolysis and disseminated intravascular coagulation in the immediate postpartum period 1
• Monitor for amniotic fluid embolism syndrome signs: hypotension, hypoxemia, respiratory failure, DIC, coma, or seizures 1

Special Populations

Patients with Glaucoma

• Consider non-prostaglandin cervical ripening procedures in women with a history of glaucoma 1

Patients Requiring Alternative Methods

• In patients with cyanotic heart disease or severe cardiovascular conditions, mechanical methods such as Foley catheter are preferable to dinoprostone 2

Comparative Effectiveness Considerations

Oral misoprostol (20-25 µg every 2-6 hours) results in fewer cesarean sections compared to vaginal dinoprostone (RR 0.84) and costs significantly less ($0.36-$1.20 per 100 µg tablet versus $65-$75 for dinoprostone gel). 3

• Misoprostol is stable at room temperature while dinoprostone requires refrigeration 3, 2
• However, dinoprostone may have lower rates of tachysystole compared to higher-dose vaginal misoprostol regimens 4, 5
• The choice between agents should prioritize cardiovascular safety profiles and contraindications specific to each patient 2

Clinical Pitfalls to Avoid

• Never administer dinoprostone concurrently with intravenous oxytocin—this is an absolute contraindication 1
• Do not use dinoprostone in any woman with prior uterine surgery, as the uterine rupture risk is unacceptable 2, 1
• Avoid dinoprostone in women with any active cardiovascular disease due to hemodynamic instability risks 2
• Ensure continuous monitoring capability is available before initiating dinoprostone, as complications require immediate intervention 1