There are very good studies of antivirals during pregnancy. Experts have very good consensus in this area. Please read the following article:
http://www.medscape.com/viewarticle/807416_2
Currently, antiviral treatment is recommended in the third trimester for women with very high viral load to further reduce the risk of vertical transmission. Tenofovir has been shown in some studies to be safe to be taken throughout the whole pregnancy.
Please read the article carefully and discuss your situation with both your liver specialist and gynaecologist/obstetrician.
not allowed on pregnancy, only tenofovir (viread) is good on preganancy, no resistance, most potent on hbv and even much cheaper than entecavir, it is also about to lose patent so it may become as cheap as indian generics which are as low as 21usd per month
peginterferon must be used after 3-5 years on tenofovir to work and clear hbv, hbsag is cleared in 50%
peginterferon monotherapy can work only for very low hbsag and very low hbvdna otherwise it is useless to try just 7% hbsag clearance
you also must supplement vitamin d3 and make serum levels vitd25oh 90-100ng/ml, this is a must for all hbv carriers on or off therapy, about 10.000iu of d3 daily needed