Comparison Between Oral and Vaginal Administration of Misoprostol on Uterine Contractility.
KH Danielsson, et al (Karolinksa Hosp, Stockholm; Univ of Medicine and Dentistry of New Jersey, Strafford) Obstet Gynecol 93:275-280, 1999.
Misoprostol has some advantages over the other prostaglandins currently used for pregnancy termination and labour induction, including availability in tablet form, lower cost, and storage without refrigeration.
In this study thirty women with normal, intrauterine pregnancies at 8 to 11 weeks’ gestation were enrolled. They were given 0.2 or 0.4 mg of misoprostol orally or vaginally. Intrauterine pressure was recorded 30 minutes before misoprostol administration and for 4 hours thereafter. Suction curettage was performed at the end of the recording.
Contractions occurred with vaginal misoprostol and not with oral misoprostol.
Conclusions- After vaginal administration of misoprostol, long-lasting, continuously increasing uterine contractility develops; this can be only partially explained by a direct drug effect. The longer period of increased plasma concentrations of misoprostol may have also initiated the prolonged events, resulting in increased uterine contractility.
Studies have shown that the vaginal administration of misoprostol is effective for terminating pregnancies in the first and second trimesters as well as for ripening the cervix and inducing labor in term pregnancies. Misoprostol should be given vaginally instead of orally when it is used to evacuate the uterus in early pregnancy or to induce labour at term.
Use of Misoprostol During Pregnancy and Mobius Syndrome in Infants.
AL Pastuszak, et al (Univ of Toronto; Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Unidade de Genetica, Porto Alegre, Brazil; et al ) N Engl J Med 338:1881-1885, 1998.
Mobius syndrome is a congenital facial paralysis with or without limb defects and it was found that attempted abortion with misoprostol is associated with an increased risk of Mobius syndrome in infants.
Another article on same subject is
Congenital Abnormalities in Brazilian Children Associated with Misoprostol Misuse in First Trimester of Pregnancy.
CH Gonzalez, et al (Univ of Sao Paulo, Brazil; Oxford Radcliffe Hosp, England; Massachusetts Gen Hosp, Boston) Lancet 351: 1624-1627, 1998.
Objective – whereas misoprostol is not very effective as an abortifacient, it is easy to obtain in Brazil, a country in which abortion is illegal. Exposure to the teratogenic effects of misoprostol is common.
Results of this study show that the most common misoprostol phenotypes included equinovarus with cranial-nerve deficiencies. There were arthrogryposis and amyoplasia. Infants with Mobius syndrome are much more likely to have been exposed to misoprostol than were children with spina bifida. The most common total dose of misoprostol was 800 mg.
The authors conclude that the teratogenic effects of misoprostol consist mainly of vascular disruption, probably caused by brain-stem ischemia induced during contractions.
Editorial comments: Misoprostol in combination with both mifepristone and methotrexate is being used with increasing frequency as a medical method to induce abortion in early gestations. Although the effectiveness of these combination regimens are more than 90%, failure to induce abortion does occur. The results of these 2 studies indicate that use of misoprostol in early gestation may be teratogenic and cause facial paralysis as well as limb abnormalities in the fetus. This information should be transmitted to women who are using this agent to electively terminate an early pregnancy in the event that abortion does not occur with medical treatment.