Here's an interesting article on young adults, who were perinatally infected by HIV 15-25 years ago:

Aside from the social and psychological issues of living with HIV (which are significant), they are also not doing so well with suppressing the virus and maintaining the CD4 count. It's not quite clear why, but the article hints at poor adherence to drugs. Also, with some of them being infected 20-25 years ago, they may have started on non-optimal regimens. And, of course, the side effects of starting on antiretrovirals at such an early age are likely contributing as well.