ZidovudineAnti-HIV AgentsDidanosineStavudineLamivudineReverse Transcriptase InhibitorsHIV InfectionsZalcitabineInfectious Disease Transmission, VerticalHIV-1NevirapineDideoxynucleotidesDideoxynucleosidesAIDS-Related ComplexAcquired Immunodeficiency SyndromeDrug Therapy, CombinationHIV Reverse TranscriptasePregnancy Complications, InfectiousIndinavirCD4 Lymphocyte CountHIV Core Protein p24Drug Resistance, ViralBenzoxazinesThymine NucleotidesViral LoadRNA, ViralAntiviral AgentsOxazinesOrganophosphonatesDrug InteractionsAntiretroviral Therapy, Highly ActiveHIV Protease InhibitorsDrug Resistance, Multiple, ViralDrug Resistance, MicrobialBotswanaHIVNelfinavirPregnancyAnti-Retroviral AgentsAdenineDouble-Blind MethodLopinavirRNA-Directed DNA PolymeraseAppetite StimulantsSaquinavirHalf-LifeHIV SeropositivityPyrimidinonesDrug Administration ScheduleThymidine MonophosphateInfant, NewbornNucleosidesRitonavirLeukocyte CountAIDS Dementia ComplexTreatment Failure