Annual numbers of diagnoses and medical expenses for obstetric diseases in Japan: A report from the National Database of Health Insurance Claims

AimThe present study aimed to estimate the total numbers of obstetric diseases diagnosed, total amounts of medical expenses claimed for obstetric diseases, their averages per livebirth, and yearly trends in Japan.MethodsThis is a secondary analysis of the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) (data from 2015 to 2019). The target population was women of reproductive age (15-49 years old) with diseases in pregnancy, childbirth, and the puerperium, defined by having O codes according to the International Classification of Diseases 10th Revision. We calculated the numbers of obstetric diseases diagnosed, amounts of medical expenses claimed for obstetric diseases marked with the "main injury/disease decision flag," and the totals divided by the annual numbers of livebirths, by year and women's age group.ResultsFrom 2015 to 2019, both the numbers of obstetric diseases diagnosed and amounts of medical expenses claimed for obstetric diseases per livebirth were on an upward trend, whereas the total numbers of obstetric diseases diagnosed were decreased. Women in advanced age groups had a higher number of diagnoses and a higher amount of medical expenses for obstetric diseases per livebirth. "Preterm labour without delivery" had the highest amounts of medical expenses claimed for and the second highest numbers of diagnoses throughout the study period.ConclusionsThis study suggests that pregnant women in Japan would have an increasing number of obstetric complications and necessary medical expenses year by year. Further study is warranted to elucidate these trends and identify possible mitigation measures.