While in the course of normal sexual activity the woman has the protection of secretions, ten to thirty percent are still infected. And if pregnant, there is almost no way for the baby to avoid the disease.
而據國外統計，雖然在正常性交中，女性陰道因有黏液保護，不容易受傷感染，但機率仍達百分之十至卅；一旦懷孕，胎兒更幾乎無法倖免。