Another way in which the virus can be transmitted is from mother to child. Infants can become infected in the womb (possibly through the amniotic fluid) or through contact with the virus at delivery. However, infection via these routes is very rare, especially given how common the virus is.
When a child is diagnosed with genital warts, it does not automatically mean that the child is a victim of sexual abuse, although this possibility must be investigated. Children can be infected at birth by mothers who are themselves carrying HPV, and, as already noted, the infection can take months or years to produce symptoms. Children can be infected through an inanimate object, such as a towel (which, as discussed previously, is possible but unlikely), or through close nonsexual contact with a family member who is infected. Each situation must be addressed individually.
If a mother has visible warts at delivery, she can pass the virus to her child, causing warts on the larynx (voice box) and occasionally on the eyes or genital area. Laryngeal warts are treatable, although this condition can be serious and recurrent in children. The virus can be passed on to the child even if there are no visible warts at delivery; given the large number of women infected with the virus, it is surprising how rarely this occurs. The virus can be passed to the fetus while in the womb, although this route of transmission is also thought to be very rare.
Having the HPV virus does not prevent a woman from becoming pregnant, nor does it increase her risk of a miscarriage or premature labor. However, the virus sometimes becomes more active during pregnancy. If extensive warts are present at delivery, a cesarean section may be recommended, especially if the warts are extensive enough to block the birth canal. This method of delivery may decrease the risk of HPV transmission to the child, although some babies born by cesarean section still develop warts on the larynx (possibly by transmission through the amniotic fluid in the womb). Therefore, a cesarean section is usually not recommended solely for the purpose of preventing transmission of the virus to the newborn. A better approach is to treat warts well before delivery so that they are not present during and cannot interfere with delivery.