epidemiology Labor and delivery between 28-36+6 weeks 5%-10 a be the leading cause of perinatal morbidity and mortality Survival rates have increased and morbidity has decreased because of technologic advancesepidemiology ◼ Labor and delivery between 28 – 36+6 weeks ◼ 5%-10% ◼ be the leading cause of perinatal morbidity and mortality ◼ Survival rates have increased and morbidity has decreased because of technologic advances