antibiotics, called prophylactic when given as prevention rather as treatment of infection. However, long term use of antibiotics leads to resistance of bacteria. While humans do not become immune to antibiotics, the bacteria does. Thus, avoiding using antibiotics longer than necessary helps preventing bacteria from forming mutations that aide in antibiotic resistance.One of the ways to prevent or slow down the transmission of infectious diseases is to recognize the different characteristics of various diseases. Some critical disease characteristics that should be evaluated include virulence, distance traveled by those affected, and level of contagiousness. The human strains of Ebola virus, for example, incapacitate those infected extremely quickly and kill them soon after. As a result, those affected by this disease do not have the opportunity to travel very far from the initial infection zone. Also, this virus must spread through skin lesions or permeable membranes such as the eye. Thus, the initial stage of Ebola is not very contagious since its victims experience only internal hemorrhaging. As a result of the above features, the spread of Ebola is very rapid and usually stays within a relatively confined geographical area. In contrast, the human immunodeficiency virus (HIV) kills its victims very slowly by attacking their immune system. As a result, many of its victims transmit the virus to other individuals before even realizing that they are carrying the disease. Also, the relatively low virulence allows its victims to travel long distances, increasing the likelihood of an epidemic.
Pregnancy loss refers to death of the fetus at any time during pregnancy. Pregnancy loss most commonly occurs during the first trimester, when it is referred to as early pregnancy loss. Placenta praevia or vasa praevia refers to the placenta or fetal blood vessels, respectively, covering or being located close to the opening of the uterus. More than half of patients affected by placenta praevia (51.6)% have bleeding before delivery. Vasa praevia occurs in about 0.6 per 1000 pregnancies. Placental abruption involves the separation of the placental lining from the uterus of the mother. It occurs most commonly around 25 weeks of pregnancy. Uterine rupture is when the muscular wall of the uterus tears during childbirth or, less commonly, during pregnancy. Nontubal ectopic pregnancy refers to an ectopic pregnancy that occurs in the ovary, cervix, or intra-abdominal cavity.Other causes of early pregnancy bleeding include the following:

Postcoital bleeding, which is vaginal bleeding after sexual intercourse that can be normal with pregnancy. Iatrogenic causes, or bleeding due to medical treatment or intervention, such as sex steroids, anticoagulants, or intrauterine contraceptive devices. Vaginal or cervical bleeding, which may arise from many causes including fibroids, polyps, warts, tumors, vaginitis, or trauma. Importantly, these causes may co-occur with other causes of early pregnancy bleeding. Lower genitourinary tract bleeding, which may result from a urinary tract infection (UTI), strenuous exercise, or bladder cancer. Pathophysiology
Early pregnancy bleeding is usually from a parental source rather than a fetal one.