The duration of pregnancy and "due date" are calculated from the time of fertilization because that date can be accurately determined.

Question

Quizplus · Accepted Answer

The duration of pregnancy and "due date" are actually calculated from the first day of the woman's last menstrual period (LMP), rather than from the time of fertilization. This is because the exact date of fertilization may not be known or may vary from woman to woman. The due date is typically 40 weeks from the first day of the woman's LMP, although this can be adjusted based on various factors such as ultrasound measurements of fetal growth.

The Duration of Pregnancy and "Due Date" Are Calculated from the Time