25.8% of the 500 fetuses that died in utero after the 20th week of amenorrhoea died between the 28th and 32nd week, which is the 8th lunar month of the pregnancy. Among the factors that could have brought about this result at that time of pregnancy that we examined it was shown that there were important changes in the circulation, the metabolism and the immune system in the mother. In the fetus, autonomic functions started to appear and these were especially liver, hypothalamo-pituitary, and adrenal cortex functions. The placenta itself underwent changes in its quality which were necessary to compensate for fetal growth retardation. Every change that occurred in the placenta, such as immaturity, inflammation and blood flow changes, were shown to be remarkably frequent between the 28th and 32nd week and were contributory to causing fetal death. So it appears that the 8th lunar month is a very important time for the successful development of the fetus and requires more attention if morbidity and perinatal mortality are to be lowered.