In biology and human medicine, gravidity and parity are the number of times a female is or has been pregnant (gravidity) and carried the pregnancies to a viable gestational age (parity). These terms are usually coupled, sometimes with additional terms, to indicate more details of the woman's obstetric history. When using these terms:

• Gravida indicates the number of times a woman is or has been pregnant, regardless of the pregnancy outcome. A current pregnancy, if any, is included in this count. A multiple pregnancy (e.g., twins, triplets, etc.) is counted as 1.
• Parity, or "para", indicates the number of births (including live births and stillbirths) where pregnancies reached viable gestational age. A multiple pregnancy (e.g., twins, triplets, etc.) carried to viable gestational age is still counted as 1.
• Abortus is the number of pregnancies that were lost prior to viable gestational age for any reason, including induced abortions or miscarriages but not stillbirths. The abortus term is sometimes dropped when no pregnancies have been lost.