Level 1: The size of the fetus at 5 months of pregnancy. At 5 months of pregnancy, the fetus has developed to about 20 cm in length and weighs about 300 grams. The fetus at this time already has many human characteristics, such as fingers, toes, hair and nails. In addition, the fetus\’ skin becomes more transparent, allowing the outlines of blood vessels and internal organs to be seen. Level 2: Fetal organ development at 5 months of pregnancy. Fetal organs at 5 months of pregnancy.