Figure 4.

Estimated time of death for early and late perinatal deaths. The time of death of early (gray line) and late perinatal deaths (black line) was estimated from the weights and calculated regression slope from naive control fetuses and newborn kits (Figure 2) and the process shown by dashed arrow line in inset. Ordinate depicts in descending order the percentage of animals that died on each day. (a) At 22 d of gestation (E22), all the early perinatal deaths probably occurred within a day and a half after H–I. About a quarter of the late perinatal deaths also occurred within a day and a half of H–I, but the rest of the fetuses started dying after 4 d. (b) At E25, all the early perinatal deaths also occurred within 2 d after H–I; late perinatal deaths occurred throughout the remainder of the pregnancy with 47% of the late perinatal deaths occurring around birth (arrow). (c) At E29, there were few early perinatal deaths. Late perinatal deaths were the predominant form of death. H–I, hypoxia–ischemia.