Test tube babies are created when a male sperm and female egg are fused in vitro in a laboratory test tube, as some parents are unable to naturally fertilize an egg. Sexually transmitted diseases can result from unhealthy lifestyles and are discussed. Gonorrhea is caused by bacteria and affects the urogenital tract. Syphilis is caused by a spirochete bacteria and can damage reproductive organs, eyes, bones, joints, nerves, heart, and skin. Genital herpes is caused by a virus and transmitted sexually, causing genital sores and ulcers, and potentially damaging an infant's eyes or nervous system during birth. AIDS is transmitted sexually and damages immune cells, leaving the body vulnerable to infection