Level 1: Fetal size and development at 4 months of pregnancy. At 4 months of pregnancy, the fetus has grown to a size of about 10 centimeters, which is equivalent to the size of a lemon. At this time, the fetus has obvious physical features, including fingers and toes, and is able to move. The head is larger than the body and has distinct facial features, including eyes, ears, nose, and mouth. In addition, the fetal skin begins to