Final answer:
The due date for a pregnant patient is known as the Estimated date of confinement, and it's calculated as 284 days from the first day of the last menstrual period.
Step-by-step explanation:
A pregnant patient's due date can also be referred to as Estimated date of confinement (EDC or EDD). The due date is conventionally set as 284 days, or approximately 40.5 weeks, from the first day of the last menstrual period (LMP), assuming conception occurred around day 14 of the menstrual cycle. The duration of a full-term pregnancy is typically divided into three trimesters, with the third trimester showing the most significant growth of the fetus, and culminating in labor and delivery.