Maternal Herpes Antibodies & Placental Transfer: What You Need to Know

Question
Hi,

At what point in pregnancy do the mother's antibodies start crossing the placenta into the baby's body?  I am especially interested to know at what week gestation my fetus will start getting my herpes antibodies and how long will those antibodies last in my newborn baby?

Thanks for your time.  I appreciate it so much.

Answer
The baby maintains the mother's antibodies for  around 6 months after birth. However, especially with Herpes simplex, these antibodies do not give complete immunity to either the mother or the baby. That is why, if there is any lesion noted at the time of delivery, we deliver the baby by cesarean section, and that is why, even if the mother makes antibodies, she is still able to contract secondary Herpes infections.  Usually, the virus does not cross the placenta or invade unruptured membranes. If there are no lesions noted at the time you go into labor, you can have a perfectly normal vagnial delivery without transmission of the virus. Your obstetrician can give you reading materials on Herpes that will explain the entire subject. Good Luck.