Fetal development process At 20 weeks of pregnancy, the size of the fetus is about 17 cm and the weight is about 300 grams. At this time, the fetus\’s body is relatively slender, and its hands and feet are becoming more and more coordinated. At this time, the fetus has more obvious facial features, and the growth of eyebrows, hair and nails is also gradually improving. At this time, the fetal liver can also produce some bile acids and other digestive juices to prepare for feeding after birth.