One of the most common adverse pregnancy outcomes is the death of the fetus. Fetal death has a great number of different and legally mandated definitions and particularly, different reporting requirements among different countries and states, which sometimes use different parameters, including birth weight, body length and/or the clinical estimate of gestational age thresholds . Miscarriage (spontaneous abortion) and stillbirth are two general terms describing the death of the fetus, but they refer to losses that occur at different times during pregnancy. The distinction of these definitions affects the prospects for their accurate recording in vital registration systems or national stillbirth registries, community and hospital surveys, clinical research studies, together with those for measurements and comparisons. There is no universally accepted definition when a fetal death is called a stillbirth vs. spontaneous abortion; the reporting policies in the different countries and within the states of a same country are not uniformly followed and there are also differences in terms of how the gestational age is assessed and interpreted , , , .
The various definitions used therefore pose a methodological difficulty when attempting to interpret and accurately compare stillbirth rates and associated risk factors. It is therefore necessary to reach a consensus on the definition and classification for the adverse events in pregnancy data to be comparable as well as steps toward a more comprehensive evaluation of stillbirth.