Final answer:
Gravidity, parity, and abortus are important terms in perinatal history.
Step-by-step explanation:
In perinatal history, there are three important terms to consider: gravidity, parity, and abortus.
Gravidity refers to the number of times a woman has been pregnant, regardless of the outcome (whether the pregnancy resulted in a live birth, stillbirth, or miscarriage).
Parity refers to the number of pregnancies that have reached 20 weeks' gestation or beyond, regardless of the outcome. It includes both live births and stillbirths.
Abortus refers to the number of pregnancies that have ended before 20 weeks' gestation. It includes both spontaneous miscarriages and induced abortions.