The study population will consist of female participants who become or became pregnant during HIV prevention agent trials, or who have or had planned exposures in pregnancy safety studies, and the infants resulting from those pregnancies. Mother participants must still be pregnant, or have had a pregnancy outcome diagnosis less than one year before screening/enrollment, and infant participants must be less than one year old. The study may include HIV-uninfected and -infected participants. Mothers may participate in EMBRACE without participation of their infants; however, infants whose mothers have not enrolled in EMBRACE will not participate.