Incidence of instrumental deliveries in primigravidae of three different ethnic groups.
D000328:Adult; D002585:Cesarean Section; D002681:China / Q000208:ethnology; D005113:Extraction, Obstetrical; D005260:Female; D006723:Hong Kong; D006801:Humans; D009390:Nepal / Q000208:ethnology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D044465:White People