Impact of diagnostic and confirmatory tests and prenatal counseling on the rate of pregnancy termination among women with positive cytomegalovirus immunoglobulin M antibody titers

Abstract

The purpose of this study was to determine if diagnostic tests performed in a reference laboratory and the correct interpretation and communication of results by an expert physician to the patient can reduce the rate of unnecessary abortions among women with positive cytomegalovirus (CMV) immunoglobulin M antibody titers. This was a retrospective study of 1857 consecutive pregnant women with positive screening for IgM anti-CMV, in the first or second trimester of pregnancy, referred to our unit for further diagnostic evaluation. Patients with available follow-up were divided into 2 groups according to the results of confirmatory serologic testing: women with a CMV serologic profile suggestive of primary infection and hence at high risk of vertical transmission (group 1) and women with a CMV serologic profile consistent with nonprimary infection or past infection (group 2). The number of expected pregnancy terminations and the prevented fraction of abortions was calculated. Of 445 group 1 patients, 53 (11.9%) elected to terminate the pregnancy after being informed of the results of diagnostic tests; in contrast, only 5 (0.4%) women in group 2 underwent terminations (P < .001). At autopsy, 38 fetuses in group 1 proved infected. No information on fetal infection is available for pregnancies terminated in the first trimester (15 in group 1; 5 in group 2). We estimated that > or = 196 (11.9%) of all patients in groups 1 and 2 (n = 1650 patients) would have elected abortion on the basis of the positive result of screening for fetal CMV infection. After the results of confirmatory tests, only 58 women (53 in group 1 and 5 in group 2) elected to terminate the pregnancy. Thus, the number of abortions is presumed to have been decreased by 73% (P < .001). The correct interpretation and communication of confirmatory test results by expert physicians to pregnant women with positive screening for IgM anti-CMV may significantly reduce the rate of unnecessary abortions.