re: #592 transient

Conceptus: 3-5 weeks gestational age. Conception occurs at week 3. (Gestational age (GA)= menstrual age, which is easier to identify medically than the actual time of conception. Thus health professionals uniformly use GA. Embryonic age is GA-2) At this phase the conceptus is a clump of cells.

Actually, we’ve had this discussion here before, and there’s no way for doctors to determine the date of the last menstruation apart from asking the mother, who may or may not be able to give an exact date. Other than that, they sometimes estimate the gestational age (and thus the due date) based upon the development of the fetus (using sonagrams, for instance); but this is also only approximate, as feti do not all develop at the exact same rate. Look at the variance in birth weights.