Fetal size and weight Five months of pregnancy is an important period of fetal development, when the fetus has begun to take shape. Generally speaking, the weight of the fetus at this stage is about 268 grams and the length is about 16 centimeters. The fetus\’ observable muscles and bones are fully developed compared to its previous weight. As pregnancy progresses, the baby\’s skin becomes more transparent and appears red. In terms of outline, the fetal head circumference and abdominal circumference are relatively close at this time, and the abdomen is still relatively large. Fetal physical characteristics for pregnant women,