But on the other hand, the risk is extremely low, experts agree especially for women with known, long-standing infections.Neonatal herpes is not a reportable disease in most states, so there are no hard statistics on the number of cases nationwide.The risk is also high if she has prior infection with HSV-1 but not HSV-2.While acquisition of herpes in the last few weeks of pregnancy is rare, it may account for almost half of all cases of neonatal herpes.That's the major reason that mothers with recurrent genital herpes rarely transmit herpes to their babies during delivery.Even women who acquire genital herpes during the first two trimesters of pregnancy are usually able to supply sufficient antibody to help protect the fetus.If you are pregnant and you-have genital herpes, you will want to talk with your obstetrician or midwife about how to manage the infection and minimize the risk to your baby.If you are a man with either oral or genital herpes and your partner is uninfected and pregnant, you can do even more to protect the baby.
There is a high risk of transmission if the mother has an active outbreak, because the likelihood of viral shedding during an outbreak is high.
Herpes antibodies in the mother's blood cross the placenta to the fetus.
These antibodies help protect the baby from acquiring infection during birth, even if there is some virus in the birth canal.
If a woman has primary herpes at any point in the pregnancy, there is also the possibility of the virus crossing the placenta and infecting the baby in the uterus.
About 5% of cases of neonatal herpes are contracted this way.