DefinitionA threatened miscarriage is a condition that suggests a miscarriage might take place before the 20th week of pregnancy.Alternative NamesThreatened miscarriage; Threatened spontaneous abortion; Abortion - threatened; Threatened abortionCauses, incidence, and risk factorsA small number of pregnant women have some vaginal bleeding, with or without abdominal cramps, during the first trimester of pregnancy. When the symptoms indicate a miscarriage is possible, the condition is called a "threatened abortion." (This refers to a naturally occurring event, not medical abortions or surgical abortions.)Miscarriage occurs in just a small percentage of women who have vaginal bleeding during pregnancy.For more information, see: MiscarriageSymptomsSymptoms of a threatened miscarriage include:Ab