The average 23-week fetus measures 11.4 inches from head to foot and weighs 1.1 pounds. IBaby already hears your voice with more clarity – which makes this a great moment to talk, read stories, sing… Studies show fetuses have a bigger preference for classical music during their “stay” inside the womb, with a special likening to Vivaldi. The pancreas is ready to produce insulin, which maintains the glucose in the blood under control. The amniotic liquid keeps the baby warm and protects it from infections.