Induction of Second Trimester Abortion Using Isosorbide Mononitrate And Misoprostol Compared To Misoprostol Alone A Double Blinded Randomized Placebo Controlled Trial

Abstract

The need for termination of pregnancy in the second trimester has significantly increased due to the wide scale introduction of prenatal screening programs. Women whose pregnancies are associated with medical disorders or associated with serious fetal anomalies, termination might be a must. Misoprostol (Cytotec) is synthetic prostaglandin E, and is currently available as a 200-μg tablet for prevention of peptic ulcers. It has been used "off label" for preinduction cervical ripening and labor induction. Nitric oxide nitric oxide releasing drugs are a novel class of effective and safe agents for cervical ripening. Several studies have shown the promising role of nitric oxide donors in obstetrics. They are cheap and have a good safety profile. Our research aimed to study the efficacy and safety of nitric oxide donors when combined with prostaglandins in induction of second trimester abortion expecting that both drugs when used together will be of greater efficiency and associated with less side effects. Our study included 90 women with gestational age between 13weeks+0day and 26weeks+6days indicated for pregnancy termination due to maternal or fetal cause. The participant females were randomly assigned to either one of two treatment groups. Group A (45 women): will receive nitric oxide donor (NO donor) isosorbidmononitrate (IMN) formulated as tablets in combination with misoprostol. Group B (45 women): will receive placebo tablets of similar design as the IMN tablets (made of starch) in combination with misoprostol. Misoprostol was administered as 400mcg initial dose followed by 200mcg every 4 hours in addition to either IMN or placebo. There was a statistically significant difference between the two groups in the number of doses given and the number of doses given within the first 24 Hours. Approximately 78.5% of cases group needed two doses or less compared to about 25.8% in the controls. Within the first 24 Hours, 91.1 of cases group had successful induced abortion compared to 77.8% of the controls and the difference was statistically insignificant. The mean time needed for abortion was 7.42 in the drug group compared to 11.68 in the control group and difference was significant. The number of women who complained of headache and bleeding in the drug group was more than that of the control group. We concluded that the compination of misoprostol with isosorbid mononiterate in more effective than misoprostol alone in induction of second trimester abortion but is associated with more side effects as headache and bleeding.