Strength and limitation
The limitations of the current study are that the results were examined
based on subjective evaluation of both SMI and pathology, although
pathologic evaluations are usually performed based on subjective
evaluations. While it is considered that a certain degree of consensus
is achieved between pathologists regarding the pathological findings,
there is no established consensus for diagnosing using SMI even though
few inter-observer errors have been established. Previous studies have
quantitatively evaluated placental Doppler intensity, such as vascular
index and flow index 4. Conventional color Doppler
detects both villous blood flow and gross intervillous blood flow .
However, we believe that the strength of placental pathological
evaluation using SMI is that the blood flow from the mother and fetus
can be distinguished. The method of qualitative evaluation based on the
pathology, instead of quantitative evaluation, would be more exact and
useful in the perinatal management of placental abnormalities.