Advantages of hyperosmolar urea and PGF2

1. Low failure rates
2. Need for additional doses of PGF2α is almost eliminated
3. Expulsion of live fetuses is significantly reduced

Post Amnio-Infusion Care

Intravenous oxytocin should not be used before the delivery of the fetus unless the membranes are ruptured and there is no uterine activity. If there is no uterine activity, prostaglandin suppositories or intramuscular 15-methyl-prostaglandin are useful.

After the fetus is passed, the patient should be examined to determine if the placenta is in the uterus, the cervix, or the vagina. In the latter two circumstances the placenta should be removed. If the placenta remains within the uterus, the infusion of intravenous oxytocin, 80 to 100 U/L of lactated Ringer’s solution is appropriate.

Observation to allow for spontaneous evacuation of the uterus can extend to eight hours if the patient is afebrile and bleeding is minimal. The patient should be examined periodically to check for the placenta within the vagina.  If the placenta is retained beyond this period, the uterus needs to be evacuated using ring forceps. It is rarely necessary to go to the operating room.

After all POC have been evacuated, the cervix should be examined for trauma.

(c) Extra-Amniotic Prostaglandin

Extra-amniotic PGF2α and PGE2 is safe and effective in the termination of second trimester pregnancies. This method is useful in cases of late second trimester abortion or when access into the amniotic cavity is difficult. A small 12-gauge Foley catheter is passed through the cervical canal and the bulb inflated with 15 mL of saline solution. The bulb is within the uterus but extra-amniotic. The small size of the bulb limits trauma to the extra-amniotic space and reduces the risk of intravascular infusion and hypertonic contractions. PGF2α, 0.5 to 1.0 mg diluted in saline is given intermittently and titrated to the severity of contractions.

There must be an interval between the cessation of prostaglandin infusion and the administration of oxytocin to decrease the risk of hypertonic contractions and the potential for uterine rupture.

(d) IM Carboprost (15-Methylprostaglandin F2α, Prostin/15M, Hemabate)

Carboprost is a synthetic 15-methyl form of PGF2α that is resistant to enzymatic degradation. As a result, carboprost is more potent, and has increased smooth muscle stimulation and longer duration of activity than PGF2α and PGE2. Thus it can be administered intramuscularly.

In patients not responding to conventional therapy, IM carboprost is successful in approximately 95% within 10 to 20 hours.  The recommended dose for failed late second trimester termination is 250 ìg by deep intramuscular injection, with the dose repeated every two hours as needed. The total dose can range from 1250 to 2500 ìg. The use of multiple osmotic dilators should decrease the injection to abortion time.

Oxytocin should not be used concurrently with carboprost and should not be started until at least four hours after the final dose, unless the fetus has been passed.