Vertical transmission is not a great concern. A recent study (E. Smith et al.), different from some others that have looked at vertical transmission due to it's large number of subjects, found low rates of HPV among newborns even though a fair number of mothers were HPV-positive. Keep in mind that just because HPV DNA is detected, it doesn't mean the child will develop an established infection that will cause an HPV-related disease. In most of these studies, the number of newborns with HPV will decrease over time, possibly due to antibodies acquired from the mother dealing with the infection.
For more go to http://www.hindawi.com/journals/idog/2010/326369.html
. The study I reference is Evidence for Vertical Transmission of HPV from Mothers to Infants
published last year in Infectious Diseases in Obstetrics and Gynecology