Final answer:
It is true that a missed abortion refers to the fetal death before 22 weeks of gestation without expulsion from the uterus. It's a type of miscarriage and is closely related to the topic of fetal viability.
Step-by-step explanation:
A missed abortion does indeed refer to a situation where the fetus has died but has not been expelled from the uterus before 22 weeks of gestation. This is true. It is a type of spontaneous abortion or miscarriage and should not be confused with the voluntary termination of a pregnancy. The term miscarriage is often used to describe the spontaneous termination of a pregnancy within the first trimester, whereas a missed abortion may not be discovered until a routine ultrasound scan indicates that the embryo or fetus is no longer viable, but no physical miscarriage symptoms have occurred.
Fetal viability is another key concept in the context of pregnancy terminations, as it refers to the fetus's ability to survive outside the uterus. Generally, this is considered possible at approximately 24 weeks of gestation. However, with advances in medical technology, some fetuses born earlier may survive with intensive care.