Premature baby. Close-up of a premature baby in an intensive care unit. A ventilator (at lower image) maintains the child's breathing. The three electrodes attached to the baby's chest are connected to an electrocardiography machine to monitor heartbeat. The fourth sensor on the baby's abdomen monitors lung movement. Various drips attached to the baby's arms and legs will supply antibiotic drugs and iron and vitamin supplements. About 5-10% of babies in developed countries are born before 37 weeks gestation, often for no apparent reason. Of babies born at 28 weeks gestation and given specialist care, approximately 80% survive.