Breathing patterns before death in fetal lambs.

Continuous observations in 16 fetal lambs over many days before death in utero from hypoxia, asphyxia, infection, and other causes have shown that death is preceded by variable changes in breathing movements. There was always a prolonged period of apnea succeeded by continuous abnormal breathing in six lambs and by gasping or brief episodes of abnormal breathing in the remainder. These abnormal patterns are described as a warning of what may be encountered in the human fetus.