High Quality Content by WIKIPEDIA articles! The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) is a coding of diseases and signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or diseases, as classified by the World Health Organization (WHO). This page contains ICD-10 Chapter XVI: Certain conditions originating in the perinatal period. The perinatal period is from 22 completed weeks (154 days) of gestation (the time when birth weight is normally 500 g) to 7 completed days after birth.