Risk of miscarriage after previously induced abortion

Background: The risk of miscarriage is approximately 15 % of clinically recognized pregnancies, most of them appearing in first trimester. Miscarriage is known to be a distressing event in a woman s life. Hence, it would be in the patients favor to find any association which reduces the risk of miscarriage. On the other hand, it is estimated that 30 – 50 % of all women undergo at least one induced pregnancy termination in their lifetime, making any link between miscarriage and induced termination important. Objectives: The purpose of this literature review is to investigate if there is any increased risk of miscarriage in women who previously have undergone induced abortion. This thesis will review the impact both prior surgical and medical termination has on subsequent pregnancies in terms of miscarriage. Methods: The searching tools Pubmed, Sciencedirect, McMastersPluus and Cochrane Library have been used. They have been non-systematically searched with the words: prior induced termination, surgical termination, medical termination, spontaneous abortion, miscarriage, pregnancy outcomes, reproductive outcomes and birth ouctomes. Results: Fourteen articles were reviewed. Twelve were looking at the association between surgical abortion and miscarriage and two at the association between medical abortion and miscarriage. Three review articles and eleven original studies are included. Two of the review articles conclude with increased risk of miscarriage after surgically induced abortion, while six of the nine primary studies looking at the risk of miscarriage after surgical abortion state increased risk. Of these six studies, two show increased risk of early miscarriage, two show increased risk of late miscarriage and the rest two studies show increased risk of miscarriage at non-specified gestational week. None of the two primary studies which looked at the impact medical abortion has on the risk of miscarriage show any increased risk. In total, eight of the fourteen studies conclude with increased risk of miscarriage after induced abortion. Conclusion : It is suggestive that medically induced termination does not increase the risk of miscarriage in the subsequent pregnancies. However, there is difficult to draw a firm conclusion on the risk of miscarriage in women with prior surgically induced abortion based on the findings in this thesis. The results are conflicting and inconclusive. Further research, methodologically stronger, is needed to assess the risk