The obstetrician has every reason to expect a normal infant once the vertex has reached the perineum after a normal labor and an uncomplicated antepartum course. The authors have found, however, that hazards still face the infant at this time.A study was undertaken to determine the number and nature of these unanticipated full-term fetal deaths which occurred in the terminal phase of labor. From 1932 through 1949, 52,120 full-term deliveries were conducted at the New York Lying-In Hospital. In this group were 1,135 full-term fetal deaths, of which 775 were stillborn or deadborn. Thirty-eight, or 5 per cent, satisfied the criteria of this study and could be called unanticipated fetal deaths.Cord complications ranked highest; 14 infants were asphyxiated from anoxia secondary to cord coils around the neck or shoulder. In addition, 1 vasa previa, 1 intrauterine rupture of the umbilical cord, and 1 prolapse of the cord contributed to the fetal mortality. In this group short cord was of no particular significance.Late premature separation of the placenta followed with 6 cases. No compensatory acceleration of the fetal heartbeat, as described by Richardson,11 was detected. Although a short cord is believed to be a major contributing factor we were unable to substantiate this claim. Examination of the placenta did not reveal any consistent abnormality.Shoulder dystocia was responsible for 4 deaths and occurred in infants between 4,600 and 6,280 grams. Though theoretically complicated by excessive weight, we have included this group since estimation of the fetal size is a difficult problem. Prolonged second stage and excessive sedation each added 3 cases to the group. Some question as to the interpretation of these cases would, undoubtedly, exist, but when consideration was given to each individual case the authors felt that they should be placed in one or the other category. Finally, no apparent cause for fetal death could be found in 5 cases.Fetal death was always signaled by a bradycardia and never a tachycardia. The presence of fresh meconium coupled with fetal heart deceleration heralds profound and terminal asphyxia, but an absence of meconium does not preclude anoxia in the presence of a bradycardia. A brief discussion of the physiological aspects of anoxia relative to this problem is presented. Consideration of the management of the perineal stage of labor and subsequent delivery has also been considered.