Objective: To determine the frequency of intrauterine rubella infection in Taiwan.
Methods: One hundred three pregnant women with evidence of rubella infection were enrolled. Congenital rubella infection was diagnosed by testing specific immunoglobulin (Ig) M in fetal cord serum obtained from funipuncture or amniotic fluid culture. The fetal outcomes were evaluated by ultrasonic examination, specific antibody detection in cord blood at birth, and complete physical examination during early childhood.
Results: Prenatal diagnosis was possible in 95 of 103 fetuses, 93 by funipuncture and two by amniocentesis. Five intrauterine rubella infections were detected prenatally, and another one was diagnosed after birth. The intrauterine infection rates were 10.0, 11.8, 2.9, and 6.5% after maternal infection at 1-10, 11-14, 15-19, and 20-29 gestational weeks, respectively. Among the six fetuses with serologic evidence of congenital infection, one had congenital rubella syndrome with sensorineural deafness, two were terminated during the second trimester, two others were normal, and one was lost to follow-up. With the exception of the infant with clinical congenital rubella syndrome, no evidence of rubella defects was found in the other 81 children who received follow-up to 2-4 years old.
Conclusion: The risk of congenital rubella infection in seropositive pregnant women is relatively low in Taiwan.