Objective: To compare the effectiveness and safety of isosorbide mononitrate (IMN), misoprostol (MP), and mechanical dilatation (MD) for cervical ripening in second-trimester abortions.
Methodology: The present study was conducted in the Department of Obstetrics and Gynaecology, MGM Medical College, Indore, Madhya Pradesh, from September 2014 to August 2015. One-hundred and fifty women who had a valid indication for termination were included after informed consent and randomized into three groups of 50 each. Women with hypotension BP 8 mm were excluded.
Results: In the study, indications for termination were fetal conditions (14.6%), maternal conditions (19.3%), contraceptive failure (39.3%), IUFD (16.6%), and others (10%). The mean ± SD of Bishop score before and after IMN were 1.18 ± 1.43 and 4.54 ± 1.70, whereas for MP, 1.2 ± 1.525 and 4.76 ± 1.80, and for MD, 1.3 ± 1.46 and 4.36 ± 1.56, respectively (p = 0.000 significant). The mean ± SD of induction ripening interval of 10.9 ± 3.23, 9.76 ± 3.17, and 12.92 ± 2.65 for IMN, MP, and MD (p = 0.000) shows that it was least for MP followed by IMN and MD. Comparison of induction–abortion interval showed mean ± SD of 28.32 ± 9.84, 29.00 ± 7.22, and 38.76 ± 9.87 for IMN, MP, and MD, respectively (p = 0.000). All cases of IMN and MP aborted vaginally; in MD group, 4% had a hysterotomy. Side effects were minimal in IMN group with only headache which was tolerable.
Conclusion: IMN when compared with MP and MD proved to be a good cervical ripening agent for second-trimester abortions. It is safe, effective, and has minimum side effects. More studies are required for establishment of IMN as a ripening agent.
Word RA, Li XH, Hnat M, et al. Dynamics of cervical remodeling during pregnancy and parturition: mechanisms and current concepts. Semin Reprod Med 2007;25(1):69–79. DOI: 10.1055/s-2006-956777. Available from: https://pubmed.ncbi.nlm.nih.gov/17205425/.
Ho PC, Tsang SS, Ma HK. Reducing the induction to abortion interval in termination of second-trimester pregnancies: a comparison of mifepristone with laminaria tent. Br J Obstet Gynecol 1995;102(8): 648–651. DOI: 10.1111/j.1471-0528.1995.tb11404.x. Available from: https://pubmed.ncbi.nlm.nih.gov/7654644/.
Maradny EE, Kanayama N, Halim A, et al. Biochemical changes in the cervical mucus after application of laminaria tent. Acta Obstet Gynecol Scand 1996;75(3):203–207. DOI: 10.3109/00016349609047087. Available from: https://pubmed.ncbi.nlm.nih.gov/8607329/.
Lim CED, Ng RWC, Xu K. Non-hormonal methods for induction of labour. Curr Opin Obstet Gynecol 2013;25(6):441–447. DOI: 10.1097/GCO.0000000000000027. Available from: https://pubmed.ncbi.nlm.nih.gov/24121598/.
Chen W, Xue J, Peprah MK, et al. A systematic review and network meta-analysis comparing the use of Foley catheters, misoprostol, and dinoprostone for cervical ripening in the induction of labour. BJOG 2016;123(3):346–354. DOI: 10.1111/1471-0528.13456.
Ekerhovd E, Brännström M, Weijdegård B, et al. Nitric oxide synthases in the human cervix at term pregnancy and effects of nitric oxide on cervical smooth muscle contractility. Am J Obstet Gynecol 2000;183(3):610–616. DOI: 10.1067/mob.2000.105901.
Romero R. Clinical application of nitric oxide donors and blockers. Human Reprod [Oxford, England] 1998;13(2):248–250. DOI: 10.1093/humrep/13.2.248. Available from: https://pubmed.ncbi.nlm.nih.gov/9557813/.
Thomson AJ, Lunan CB, Cameron AD, et al. Nitric oxide donors induce ripening of the human uterine cervix: a randomised controlled trial. Br J Obstet Gynaecol 1997;104(9):1054–1057. DOI: 10.1111/j.1471-0528.1997.tb12066.x. Available from: https://pubmed.ncbi.nlm.nih.gov/9307534/.
Li CFI, Chan CWC, Ho PC. A study of the efficacy of cervical ripening with nitric oxide donor versus placebo for cervical priming before second-trimester termination of pregnancy. Contraception 2003;68(4):269–272. DOI: 10.1016/s0010-7824(03)00170-7. Available from: https://pubmed.ncbi.nlm.nih.gov/14572890/.
Ledingham MA, Thomson AJ, Lunan CB, et al. A comparison of isosorbide mononitrate, misoprostol and combination therapy for first trimester pre-operative cervical ripening: a randomised controlled trial. BJOG 2001;108(3):276–280. DOI: 10.1111/j.1471-0528.2001.00041.x. Available from: https://pubmed.ncbi.nlm.nih.gov/11281468/.
Arteaga-Troncoso G, Villegas-Alvarado A, Belmont-Gomez A, et al. Intracervical application of the nitric oxide donor isosorbide dinitrate for induction of cervical ripening: a randomised controlled trial to determine clinical efficacy and safety prior to first trimester surgical evacuation of retained products of conception. BJOG 2005;112(12):1615–1619. DOI: 10.1111/j.1471-0528.2005.00760.x. Available from: https://pubmed.ncbi.nlm.nih.gov/16305563/.
Ekerhovd E, Bullarbo M, Andersch B. Vaginal administration of the nitric oxide donor isosorbide mononitrate for cervical ripening at term: a randomized controlled study. Am J Obstet Gynecol 2003;189(6):1692–1697. DOI: 10.1016/s0002-9378(03)00865-2. Available from: https://pubmed.ncbi.nlm.nih.gov/14710100/.
Rameez MFM, Goonewardene IMR. Nitric oxide donor isosorbide mononitrate for pre-induction cervical ripening at 41 weeks’ gestation: a randomized controlled trial. J Obstet Gynaecol Res 2007;33(4):452–456. DOI: 10.1111/j.1447-0756.2007.00573.x. Available from: https://pubmed.ncbi.nlm.nih.gov/17688611/.
Shafique U, Kazmi F, Rehana F. Vaginal isosorbide mononitrate and misoprostol for induction of cervical ripening prior to 1st trimester surgical evacuation of retained products of conception. Journal of Rawalpindi Medical College 2010;14(2):101–103. Available from: http://journalrmc.com/index.php/JRMC/article/view/702.
Mousiolis A, Sindos M, Papantoniou N, et al. Can isosorbide mononitrate be useful in second trimester termination of pregnancies? Contraception 2013;88(1):41–44. DOI: 10.1016/j.contraception.2012.11.018. Available from: https://pubmed.ncbi.nlm.nih.gov/23290428/.
Osman I, MacKenzie F, Norrie J, et al. The “PRIM” study: a randomized comparison of prostaglandin E2 gel with the nitric oxide donor isosorbide mononitrate for cervical ripening before the induction of labor at term. Am J Obstet Gynecol 2006;194(4):1012–1021. DOI: 10.1016/j.ajog.2005.10.812. Available from: https://pubmed.ncbi.nlm.nih.gov/16580290/.
Dave A, Nigam P, Maru L. Isosorbide mononitrate a nitric oxide donor: a study of its efficacy and safety as an agent for cervical ripening. J Obstet Gynaecol India 2015;65(3):162–166. DOI: 10.1007/s13224-014-0577-5. Available from: https://pubmed.ncbi.nlm.nih.gov/26085736/.
Sivakumar S, Nalina S, Fathima R, et al. Comparison of misoprostol and misoprostol with isosorbide mononitrate in second trimester termination of pregnancy. J Evid Based Med Healthcare 2016;3(63):3424–3429. DOI: 10.18410/jebmh/2016/737.
Dixi MS, Somalwar SA, Tathe GR. Effectiveness of isosorbide mononitrate vs prostaglandin E2 gel for cervical ripening: a study. J South Asian Feder Obstet Gynaecol 2019;11(5):288–291. DOI: 10.5005/jp-journals-10006-1712. Available from: https://creativecommons.
Chhetri S, Pokharel H, Rijal R, et al. Assessment of the efficacy of different methods of second trimester abortion: an initial experience in eastern Nepal. JSAFOG 2015;7(3):182–184. DOI: 10.5005/jp-journals-10006-1352.