RESUMEN
Total 8,341 pregnant women who visited Obstetric Clinic Cheil General Hospital from Jaunary 1991 to July 1992 were screened for HBsAg. Sixty five women with positive HBsAg who delivered healthy babies during that period and their infants are included in the study. HBsAg, Anti-HBs, Anti-HBc, HBeAg and Anti-HBe were tested by radioimmunoassay and hepatitis B virus DNA were studied by polymerase chain reaction technique in both mothers' and babies serum. The results were as follow: 1) Among 8,341 pregnant women who were screened for HBsAg 374 were asymptomatic carriers(4.5%). 2) The newborn babies born to 65 mothers who were positive HBsAg showed HBsAg in 4.6%, HBeAg 75.0%, anti-HBc 98.4% and hepatitis B virus DNA in 26.2%. 3) It showed discordance of HBeAg/anti-HBe, with hepatitis B virus DNA in newborn infants. 4) Follow up study at 8~20 months showed HBeAg and hepatitis B virus DNA in 2 infants out of 20.