One-hundred foetuses were evaluated by Behery and colleagues
[13] with colour Doppler US between the gestational
weeks 26-34, and forty-three of them had growth retardation.
Renal artery PIs were detected at 0.79 and 1.75, respectively,
in normally growing foetuses and growth restricted foetuses,
and there were statically significant correlations between
these two groups [13]. Also, there were significantly negative
correlations between the foetal arterial pO2
and AFI. Renal
resistance and renal artery PI increased because of the
reduced foetal arterial pO2
and AFI.