By Emma Simpson
BBC News, Moscow
Russia has one of the fastest growing Aids epidemics in the world, with 100 new infections every day. Increasingly, women and their infants are being affected.
Latest figures show 22,000 babies have been born to HIV-positive women. And many are being abandoned by their mothers into the care of the state.
Many HIV-positive mothers give up their babies to the Russian state
The four babies in the maternity ward in the city of Tver were just a few days old and blissfully content.
But two of them had been abandoned by their HIV-positive mothers, who were either too ashamed or unable to cope.
They ought soon to have been heading to one of Russia's regular baby orphanages, but the two newborns are likely to be stuck here in this state-run infectious diseases hospital instead.
If they are lucky it will be only for 18 months - the time it takes doctors in Russia officially to diagnose whether children are HIV-positive.
Most babies born to women who are HIV-positive do turn out to be free from the virus.
But if HIV is detected, the babies could end up being here a lot longer. Russia is quick to reject those with HIV.
In another part of the hospital, we found Tanya sitting in her dressing gown in a nurse's office, doodling happily away. She was three-and-a-half years old and had been living here all her life.
Tanya had never played with another child and had only been outside once or twice.
The staff told us that because she was HIV-positive, there was nowhere else for her to go, an outcast whom nobody seemed to want.
In this region, there were 23 new cases of children confirmed with HIV last year alone - and sadly, we discovered that Tanya's case was not unique.
Yury Loshkarov, in charge of Tver's health department, admitted that there were other children living in its hospitals because no orphanage wanted to take them.
"If they're abandoned, they stay in a hospital," he said.
In Russia, some 20 babies are born every day to HIV-positive women, with two of those, on average, abandoned by their mothers.
We spoke to Olga, who found out a year ago that she was HIV-positive.