Why perinatal mortality cannot be a proxy for maternal mortality

In recent years, the perinatal mortality rate (PNMR) has been proposed as a proxy measure of maternal mortality, because perinatal deaths are more frequent and potentially more easily measured. This report assesses evidence for an association between these two statistics. This study, based upon data from Matlab, Bangladesh, shows that the maternal mortality ratio (MMR) and the PNMR do not vary together over time, and that the PNMR does not reliably indicate either the magnitude or the direction of change in the MMR from year to year. Statistical analysis shows that the correlation between the PNMR and the MMR is not significantly different from zero. An examination of the major causes of maternal and perinatal deaths indicates that the two measures cannot be expected to vary together. Almost half of perinatal deaths result from causes that do not pose a threat to the mother's life, and almost half of maternal deaths result from causes that do not lead to perinatal death. Monitoring of the PNMR can give an inaccurate picture of maternal mortality and should not be used as a proxy.