Instillation abortion is performed by injecting chemicals into the amniotic sac to induce uterine contractions which expel the fetus and terminates a pregnancy. The chemicals used in an instillation abortion are saline, urea or prostaglandin. Dilation and curettage can be used to remove any remaining uterus tissue
Before performing a instillation abortion the cervix is usually dilated 12-48 hours before the procedure. Instillation abortion was developed by Eugen Aburel in 1934 for late trimester pregnancy termination. Saline is in general safer and more effective than the other intrauterine solutions because it is likely to work in one dose.
Prostaglandin is fast-acting, but often requires a second injection, and carries more side effects, such as nausea, vomiting, and diarrhea. The rate of mortality reported in the United States between 1972 and 1981 was 9.6 per 100,000 for instillation methods. This is in comparison to rates of 4.9 per 100,000 for D&E and 60 per 100,000 for abortion by hysterotomy and hysterectomy.