Although Most Pregnancies Proceed Without Any Major Difficulties, Some People

Although most pregnancies proceed without any major difficulties, some people do experience loss during pregnancy, most often through miscarriage.Which of the following are not issues surrounding miscarriage described in your text?

A) It is sometimes referred to as spontaneous abortion.
B) It occurs, by definition, before the 20th week of pregnancy.
C) About 50% of miscarriages occur during the first 12 weeks of pregnancy.
D) Miscarriages that occur between weeks 12 and 20 are considered "late" miscarriages.