Do I need to avoid pregnant woman and a new born baby...?  

If you have chicken pox, you should isolate yourself. It is an airborne disease and is very contageous to every one around you. I am not a doctor, but I can still remember what my pedia said when my children caught that disease. My children were advised to rest and drink lots of fluids and told them not to go out of the house because they might inflict others. It is very dangerous also for pregnant women to be inflicted with chicken pox as this also affects the baby in their womb. Try researching the web for this illness so you can understand better. I hope you will follow your doctor's order so as not to affect others. Get well soon!

Because pregnant women are very prone to be infected if exposed to someone with chickenpox. Plus if she gets infected the baby who is developing in her might not be able to cope with that infection and suffer the most than the mother. New born babies are usually not yet immuned to chickenpox and they are only given the vaccine later in their life so they are prone to get infected.