The reductions in perinatal mortality was seen immediately after the introduction of artificial surfactant for the treatment of neonatal respiratory distress syndrome (Fig. 6). These changes highlight the effects of improvements in medical care on maternal and perinatal mortality. Although improved economic conditions indirectly result in improvements in perinatal mortality, similar improvements have not always been seen in neonatal mortality. The factor that directly contributes to reductions in maternal and perinatal mortality is timely and appropriate medical intervention for the mother, fetus and neonate. Therefore, perinatologists ensure that their medical knowledge is up to date
to enable them to provide mothers and babies with the best possible medical care. Neonatal mortality in 1000 live births has been also reported from 1899 at the same time as maternal mortality. see more Initially, it was 77.9 in 1899, 79.0 in 1900, and then decreased to 27.4 in 1950, 1.8 in 2000 and 1.1 in Venetoclax 2010, which was the lowest in the world (Fig. 7),
indicating the successful efforts of neonatologists in Japan in the care of low birthweight to extreme low birthweight infants, who were born after preterm labor, particularly in the neonatal intensive care unit (NICU). The neonatal mortality closely correlates with maternal mortality through 1900 to 2010 (Fig. 8), despite maternal and neonatal mortalities being independent variables in the perinatal statistics. It could be speculated
that this could possibly indicate the presence of a deep relation between mother and child. The perinatal mortality after 22 weeks of pregnancy was estimated using the regression equation of the Figure 5 legend, and the perinatal mortality after 28 weeks of pregnancy was estimated using the regression equation of Maeda, for the years when there was no perinatal mortality report (Table 3). An estimated perinatal mortality from maternal mortality using the regression equation for 28 weeks of pregnancy was 135/1000 births, while it was 423 for 22 weeks of pregnancy using the equation in Figure 5 in 1900 (Table 3), meaning that 42% of neonates died, if the perinatal mortality was calculated in the infants 3-mercaptopyruvate sulfurtransferase born after 22 weeks of pregnancy, namely, the babies born at 22–28 weeks hardly survived in 1900. The situation was remarkably improved to achieve the survival in preterm neonates born in 22–28 weeks by the efforts of neonatologists in the period between 1900 to 1979, for example, 60% of neonates whose birthweight was 400–500 g, compatible to the births in 22–23 weeks of pregnancy, survived in the NICU of Tokyo Women’s Medical College in the period 1984−1999 (Fig. 8). In a recent cohort study in Japan, survivors to 3 years were 36% of infants born at 22 weeks of gestation, 62.9% of infants born at 23 weeks, 77.1% at 24 weeks and 85.2% at 25 weeks, where profound neurodevelopmental impairments were detected in 30.