Abortion is defined as the expulsion of the fetus before which week of gestation?

The correct choice is based on the common medical definition of abortion, which refers to the termination of a pregnancy before the fetus reaches the 20th week of gestation. This timeline is significant because medical guidelines categorize any pregnancy loss occurring before this point as an abortion, irrespective of the circumstances surrounding the event.

After the 20th week, losses are generally classified as stillbirths rather than abortions. Therefore, understanding this boundary is crucial for discussions surrounding pregnancy, reproductive health, and legal definitions of abortion. The other provided time frames do not align with this standard definition in medical practice, as they fall either before or after the critical 20-week threshold.