Step 1: on a sheet of paper, draw a fetus that is near the end of the first trimester. at this stage, an average fetus is about 3 inches and weighs about 1 oz. according to the picture presented in the slide show, draw the likeness of the fetus and draw it to scale the length it is in the womb at this stage of development. include as many details as possible, adding color to the baby's skin, eyes, and veins. step 2: on another sheet of paper, draw a fetus at the end of the 2nd trimester. at this stage, an average fetus is about 14 inches in length and 2 1/4 lbs. according to the picture presented in the slide show, draw the likeness of the fetus and draw it to scale of the size it is in the womb at this stage. again, include as many details as possible, showing the changes to the limbs, face, and internal structure. step 3: on two sheets of paper (taped together), draw a fetus that is near the end of the third trimester. the fetus at this stage is curled up, almost doubled over, so remember to consider this as you draw the fetus the correct length. an average fetus is 19 - 21 inches in length and between 6 3/4 lbs to 10 lbs. include as much detail as possible, showing the changes to the fingers, feet, and face. the image below is a picture of a fetus in the third trimester.