The term "spontaneous abortion" refers to a miscarriage that occurs before the ________ week of pregnancy.

The term "spontaneous abortion" is commonly understood in medical terminology to define a miscarriage that happens before the 20th week of gestation. This milestone is significant because it distinguishes between early pregnancy loss and later pregnancy complications. When a miscarriage occurs before this point, it is categorized as a spontaneous abortion, which is relatively common in the first trimester of pregnancy.

Recognizing this timeframe is important for healthcare providers and expectant parents because it helps in understanding the risks during early pregnancy. It also guides how medical and emotional support can be provided to individuals experiencing this type of loss. While miscarriages can occur at various stages, the 20-week cut-off is the standard used for classifying the type of pregnancy loss as a spontaneous abortion, making it the correct answer.