What condition should be suspected in a 20-year-old female who is 8 weeks pregnant with vaginal spotting and lower back cramps, having passed some tissue?

The scenario describes a 20-year-old female who is 8 weeks pregnant, experiencing vaginal spotting, lower back cramps, and passing some tissue. These symptoms are highly indicative of a spontaneous abortion, also known as a miscarriage.

At 8 weeks of gestation, the presence of vaginal spotting combined with cramping and the passing of tissue suggests that the pregnancy may not be viable and is leading to a natural termination. Spontaneous abortion is characterized by these clinical signs and is a common occurrence in early pregnancy. The passing of tissue in particular is a key feature that aligns with this diagnosis.

Other conditions such as placenta previa and ectopic pregnancy can cause vaginal bleeding and cramping but typically have different presentations and associated symptoms. A threatened miscarriage is also linked with bleeding but usually does not involve the passing of tissue. Given the combination of factors in this case, spontaneous abortion is the most consistent with the symptoms described.