Primary cytomegalovirus infection during pregnancy and congenital infection: a population-based, mother-child, prospective cohort study.

Objective This study assessed maternal cytomegalovirus antibodies, and the occurrence of primary and congenital cytomegalovirus infections, and risk factors of congenital infection after a maternal primary infection. Study design We included 19,435 pregnant women in Japan, who were tested for serum cytomegalovirus antibodies before 20 gestational weeks. Immunoglobulin (Ig) G avidity was evaluated in women with both IgG and IgM antibodies; tests were repeated at ≥28 gestational weeks among women without IgG and IgM antibodies. Result Primary and congenital infections were 162 and 23 cases, respectively. The risk ratios for congenital infection were 8.18 (95% confidence interval: 2.44-27.40) in teenage versus older women, and 2.25 (95% confidence interval: 1.28-3.94) in parity ≥ 2 versus parity ≤ 1. Of 22 live birth congenital infection cases, three had abnormal neurological findings. Conclusion We demonstrated teenage and parity ≥ 2 pregnant women as risk factors of post-primary congenital infection.