What defines an inevitable abortion?

An inevitable abortion is characterized by vaginal bleeding along with an open internal cervical os before 20 weeks of gestation. This terminology signifies that the process of miscarriage is underway and cannot be halted. The presence of vaginal bleeding typically indicates that the pregnancy is at risk, and the open internal os suggests that the cervix is dilating, further pointing toward the inevitability of the abortion.

In this context, bleeding and cervical dilation together indicate that the fetus is likely to be expelled from the uterus, thus aligning with the definition of an inevitable abortion. This situation requires close monitoring and potential medical intervention to ensure the health and safety of the individual.

The other options describe different situations related to early pregnancy outcomes but do not accurately define an inevitable abortion. For instance, a closed internal os with vaginal bleeding indicates a threatened abortion, while complete passage of fetal parts signifies a complete abortion, and a non-viable pregnancy without bleeding can refer to a missed abortion.