Objective: The purpose of this study was to determine the potential for human papillomavirus to be transmitted vertically.
Study design: We started a systematic study of children 0.3 to 11.6 years old born to mothers included in the cohort of 530 women prospectively followed up for genital human papillomavirus infections in Kuopio since 1981. So far 98 children have been examined. The examinations included medical history, clinical examination of the oral cavity and hand warts, and cytologic samples from the oral mucosa for detection of human papillomavirus deoxyribonucleic acid with polymerase chain reaction with subsequent Southern blot hybridization.
Results: Human papillomavirus deoxyribonucleic acid was found in 31 of the 98 (31.6%) oral scrapings. with MY09 and MY11 human papillomavirus primers, 12 of the 98 were positive for human papillomavirus deoxyribonucleic acid in the electrophoresis gel and in subsequent hybridization. Nineteen of the positive samples were not visible in the gel but become positive when hybridized. At delivery, 5 mothers had genital human papillomavirus infection with the same virus type found in her child. In the additional 11 mothers genital human papillomavirus infection with the same virus type as in the child was diagnosed a few months before or after delivery. Mothers of the 25 children shown to be negative for oral human papillomavirus were also human papillomavirus deoxyribonucleic acid negative at delivery. Minor hyperplastic growths of the oral mucosa were found in 21 of the 98 children (21%). One child had a papilloma where human papillomavirus 16 deoxyribonucleic acid was detected, as was also found in her mother's genital area at delivery.
Conclusions: Our results support the concept that an infected mother can transmit human papillomavirus to her child.