Historically, women have often been excluded from HIV and AIDS advocacy, treatment, and research. At the start of the AIDS epidemic in 1981, medical and scientific communities did not recognize women as a group for research. Women were excluded from clinical trials of medication and preventative measures. They were also often blocked from being subjects in clinical research with exclusionary with restrictions like "no pregnant or non-pregnant women".] The National Institutes of Health (NIH) rejected grants that were targeted at understanding HIV in low-income women of ethnic minorities.This lack of attention is often attributed[weasel words] to the prominence of the gay rights movement in the area of HIV and AIDS. HIV's clinical symptoms differ between men and women, and the focus on male symptoms caused medical professionals to overlook symptoms in women.. The first case of HIV in a woman in the US was reported in 1981.[1] In December 1982, the first cases of mother-to-child HIV transmission were recorded. The number of children infected with the virus increased throughout the decade. Zidovudine (ZDV), alternatively named azidothymidine (AZT), was introduced as a drug to treat HIV in the late 1980s, reducing the chance of mother-to-child transmission by up to 70%.