PROBLEM: About one out of six pregnancies ends in spontaneous abortion before the 17th week. In more than half of these a chromosome abnormality is present, which explains the abortion. The role of cytomegalovirus (CMV) infections in early pregnancy failure is unclear. If there is a role for CMV, a preponderance of infections would be expected in a chromosomally normal group.
METHOD: The significance of CMV in abortions has been studied by screening 80 spontaneous and nine induced abortions with known karyotype for the presence of phosphoprotein pp65, an early CMV antigen. Also, endometrial biopsies (n = 55) and menstruum (n = 10) were screened. In 11 patients more than one specimen was available for study. RESULT: The protein was present in the glandular epithelium of the decidua of spontaneous as well as induced abortions in 31 of 89 (35%) cases, irrespective of chromosomal constitution. Trophoblastic cells were pp65 positive in 6/89 cases. A total of 17 embryos could be studied, seven of which were positive. Positive staining of embryonic organs correlated strongly with the presence of the antigen in the decidua. The endometrial biopsies and menstrual discharges from women of comparable ages showed the same percentages of positive tests for pp65: 35 and 20%. Histologically positive and negative specimens could not be differentiated other than by the specific staining. In 10 of 11 patients with more than one specimen available, the results were consistent. One patient had two positive and one negative specimen.
CONCLUSION: The findings indicate that in early pregnancy cytomegalovirus is transmitted from the decidual glands to the foetus. However, we have not found indications that the presence of cytomegalovirus infection as shown by the presence of antigen is pathogenic for early pregnancy.