Which of the following is the ONLY viable pregnancy among spontaneous abortion categories?

• A. Threatened SAB
• B. Inevitable SAB
• C. Missed SAB
• D. Incomplete SAB

Answer: (A)

The key idea is viability of the pregnancy at the time of presentation. In a threatened abortion, bleeding occurs but the cervix is closed and ultrasound shows a living fetus with cardiac activity. This means the pregnancy is still ongoing and potentially viable, because nothing has progressed to tissue expulsion or cervix dilation yet. In contrast, the other categories involve factors that make continued viability unlikely: inevitable abortion has a open cervix with products of conception beginning to pass, so abortion is imminent; a missed abortion is fetal death with retained products but no bleeding or cervical change, so the pregnancy is not viable; and an incomplete abortion has partial expulsion of tissue with an open cervix, indicating the pregnancy has not continued.

Thus, among these scenarios, only threatened abortion represents a currently viable pregnancy.