A Systematic Review of the Evidence on the Effects of Cytomegalovirus on Abortion

Cytomegalovirus (CMV) is a species of Herpesviridae showing no clinical symptoms in the earlier stage of infection in pregnant women. Nevertheless, it can be transmitted to the baby through saliva, body fluids, blood and cervical secretions. The aim of this study is a systematic review of the effects of CMV on abortion. Data were collected from Web of Science (ISI), PubMed, Scopus, Ovid, and EMBASE databases published by May 2018. The keywords used included abortion, current abortion, B19, Cytomegalovirus, spontaneous abortion, and placenta. The National Institutes of Health's Quality Assessment Tool was used for quality assessment. Fifteen papers from 1993 to 2018 were reviewed 11 of which were descriptive-analytic and the remaining 6 were case-control. In the case-control studies, the control group consisted of healthy pregnant women with no history of abortion. The case group comprised women who had experienced abortion and recurrent abortion. The maximum sample size included 779 and the minimum included 17 cases of abortion. The highest incidence of CMV infection in abortion was 100% reported by Saraswathy and 97% in the study of Tarokhian. The lowest was observed by Oliveira with 0.04% and by Kakru with 16%.The results of most studies indicate that CMV infection can lead to abortion by transfer through body fluids activation of the uterine inflammatory response and immune response, as well as transfer into embryonic tissues.