Recent progress of technology in obstetrics and gynecology, particularly in perinatal medicine in Japan.

Abstract

There has been remarkable improvement in the perinatal mortality in Japan as noted in the reports of national statistics of the Ministry of Health and Welfare. It will be the least perinatal mortality among the countries in the world where the births are more than one million over the last 2 to 3 years. Namely, the mortality of Japan was less than 10 in 1,000 births in a year. This improvement was obtained by the change of socioeconomical condition until 1980, but the progress after that period is interpreted as the result of the efforts in the management of the mother and infant in the perinatal stage (Morio,1985). This effort includes that of the staffs in the clinics and also the advancements of the tools in the new technologies which have been seriously studied since the 1960s. The most important modality would be the progress of fetal monitoring in labor and pregnancy in these 20 years. The external techniques include the use of fetal heart signals detected at maternal abdomen, which is the most commonly the ultrasonic Doppler fetal heart signal, and that of external tocodynamometry. This technique resulted in the monitoring of whole labor and also the diagnosis of pregnant women prior to the onset of labor with the technique of the non-stress test (NST) which is the antepartum cardiotocogram (CTG) recorded for 40 to 60 min. mainly in high-risk patients. The management with rapid delivery after the diagnosis of fetal hypoxia with the technique reduced the unexpected fetal deaths during pregnancy and in labor, and also decreased the perinatal morbidity including neonatal asphyxia, respiratory distress and the meconium aspiration syndrome. The reduction of cerebral palsy after growing-up can be expected if the fetal monitoring and the management is adequately carried out in perinatal stage. Fetal heart rate (FHR) analysis is one of the main targets of the research in order to obtain further improvement, since the main component of the fetal monitoring has been the diagnosis of FHR records.