Proston

Indications

Dinoprostone (prostaglandin E2) is used in hospital to soften and open the cervix (the neck of the womb) and to start labour when it needs to be induced at or near full term. It is also used in some cases to empty the womb after a miscarriage or fetal death, under specialist care.

How It Works

Dinoprostone is a man-made form of a natural prostaglandin. It softens and thins the cervix (cervical ripening) by changing its connective tissue, and it causes the muscles of the womb to contract, which helps start labour.

Dosage and Administration

This is a hospital-only medicine given by a doctor or midwife, as a vaginal gel, vaginal tablet or slow-release vaginal insert placed near the cervix. The dose and timing depend on the product and on how the cervix and labour progress, and are given as prescribed. The mother and baby are monitored closely, including the baby's heart rate and the strength of contractions. The insert can be removed if contractions become too strong.

Interactions

• Oxytocin should not be started until a set time after dinoprostone, as together they can overstimulate the womb.
• Other prostaglandins such as Misoprostol increase the risk of overstimulation.
• NSAIDs such as Aspirin may reduce its effect.

Contraindications

• Previous caesarean section or major surgery on the womb.
• Baby in an abnormal position, signs of fetal distress, or disproportion between baby's head and the pelvis.
• Placenta praevia, unexplained vaginal bleeding, or active genital herpes.
• Already having strong, regular contractions, or when oxytocin is already being given.
• Allergy to prostaglandins.

Side Effects

Common: vaginal warmth or irritation, nausea, vomiting, diarrhoea, fever, back pain and overly strong or frequent contractions that can affect the baby's heart rate. Rare but serious: tearing of the womb, amniotic fluid embolism, and clotting problems.

Tell staff at once about severe or continuous tummy pain, heavy bleeding, breathlessness, chest pain or feeling faint; these need urgent medical help.

Pregnancy and Lactation

It is used only during pregnancy, to ripen the cervix or start labour, under hospital supervision. It is not used during breastfeeding for other purposes.

Precautions and Warnings

• Use with care in asthma, glaucoma, epilepsy, high blood pressure, and heart, liver or kidney disease.
• Use with care in women who have had many previous births or a twin pregnancy.
• Do not use more than directed; doses are spaced as advised.

Overdose

Too much can cause very strong or prolonged contractions and fetal distress. The insert is removed and the medical team gives treatment to relax the womb.

Therapeutic Class

Prostaglandin; uterotonic and cervical ripening agent.

Storage

Hospital medicine: store as directed on the pack, usually in a refrigerator at 2 to 8°C (some forms in a freezer), protected from light. Keep out of the reach of children.