Having to do with the foetus.

Of or pertaining to a foetus. The unborn young of an animal while still in the uterus

Of or belonging to the foetus, or embryo in course of development.

often considered the british spelling, US spelling is actually more correct, “fetus” correctly derives from the Latin fetus see alternate spelling fetal period above.

of or relating to a fetus; "fetal development"

In a lateral position with knees drawn and arms folded.