Comparison of misoprostol and misoprostol with isosorbide mononotrate in second trimester termination of pregnancy

BACKGROUND: Abortion is the termination of pregnancy by the removal or expulsion of the foetus or embryo from the uterus before the age of viability. Second trimester pregnancy termination has been reported to be associated with 3-5 times increased morbidity and mortality. Medical methods of induced abortions in the midtrimester has shown development and proven to be safe and accessible. The ideal agent for cervical softening should be clinically effective, it should have a low side effect profile and it should be easy to administer. The cervical ripening effects of nitric oxide donors and of prostaglandin might be additive. So if a small dose of nitric oxide donor is given in combination with a small dose of prostaglandin it will cause effective cervical ripening and reduce the side effects associated with larger doses of either agent used alone. OBJECTIVES: Our aim is to compare the traditional use of vaginal misoprostol versus misoprostol and Isosorbide mononitrate in medical management of second trimester abortions. The comparison involves aspects of efficacy which are evaluated by means of the difference in success rate of inducing abortion, induction to expulsion period, amount of misoprostol used rate of manual/ surgical removal of the placenta and the rate of post abortive haemorrhage and also comparison of safety profile of both drugs. METHODOLOGY: The study was conducted in the labour ward of Institute of Obstetrics and Gynaecology, Egmore (IOG) in the period from October 2014- July 2015. The patients included in the study were 100 pregnant women from 12 to 20 weeks of gestational age undergoing induced abortion. Women were divided into two groups: Group 1 – Combination of 400 mcg of misoprostol and 40 mg of ISMN placed intravaginally. Repeat doses included combination of 400 mcg of misoprostol and 20 mg ISMN every 4 hours for maximum 4 doses..Group 2 - 400 mcg of misoprostol placed intravaginally every 4 hours for maximum 4 doses. RESULTS: It was observed that in Group A. Mean induction abortion interval was significantly less (7 hrs 36 mins ) in Group A, compared with group B(9 hrs 55 min). The mean dose of misoprostol decreased in group A (848 mcg ) when compared with group B (936 mcg) In Group A 76% of the patients aborted with two doses where as in Group B 62 % of the patients aborted with two doses. It is interpreted that on adding ISMN the number of complete abortion rates are higher. There was no failure of abortion.. The side effects such as pain abdomen and fever were less in Group A(38 %) when compared to Group B(78%). Side effects specific to ISMN was very less and reported only in 2 % of study groups. There was no reported evidence of postpartum haemorrhage or increased blood loss. The drug ISMN, was also economical and cost effective. CONCLUSION : Vaginally administered ISMN seems to be safe and well tolerated and provides a merit in some situations, where uterine contractions are unwanted before cervical ripening. Combination therapy of prostaglandins with nitrates might therefore be an ideal method for second trimester termination of pregnancy