Here are your goals for this lesson: Draw the stages of fetal development to scale.
Calculate the percent growth between the different trimesters.

The development of the fetus occurs at a phenomenal rate. At no other time in your life do you go through as many changes as you do during those 9 months in your mother's womb. Can you imagine growing from 5 feet tall to 12 feet tall in just 3 months? One day, your clothes would fit you, and the next day, they would not! This is the equivalent of what occurs during the gestation period in the mother's womb.

In this activity, you will draw the stages of fetal development to scale ("to scale" means to its exact size). You will need a few pieces of white paper, some colored pencils, a ruler, and some tape.

Below is the slide show of the three trimesters from the previous lesson.

3/4The Trimesters of Fetal Development
© 2014 Glynlyon, Inc.

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.

Once you finish your fetal development representations, calculate the percentage growth between each of the trimesters. You should have three calculations: percent growth between the first and second trimester, percent growth between the second and third trimester, and percent growth between the first and third trimester.

To figure percentage, subtract the length of trimester 1 from trimester 2, then divide this amount by the measurement of trimester 1. Repeat this process for each time period requested. The first calculation is done for you here.

Example: trimester 1 = 3 inches, trimester 2 = 14 inches. 14 in - 3 in = 11 in. 11 in /3 in = 3.67 and 3.67 x 100 = 367% increase in size.