Abstract:
Objectives of this prospective study was to ascertain the value of these tests in detecting
foetal acidosis. All the mothers from 25 to 35 years of age who underwent cesarean sections
performed by the author from the 1st of June to 31st of December 2002 excludmg ones who
are in the active phase of the labour, diagnosed IUGR and mothers with any medical disoder
(n=95). CTG , S/D ratio of the umbilical arterial Doppler flow, cord arterial blood PH were
performed in all. Color of the aminotic fluid and Apgar score were recorded. CTGs were
cassified accordinf to Mayer-Menk scoring system and the traditional method. Thecut off
values of pH for acidosis and the S/D ratio were taken as 7.2 amd 3.0 respectively. CTG
hoth trand the Apgar score had the lowest sensitivity ( 25 percent). But specificity and
positive predictive values of Apgar score were 100 percent.The negative predictive value
was above 90 percent in all except when the meconium status of amniotic, fluid with CTG
in above 90 percent in all except when the meconium status of amniotic, fluid with CTG in
47.82 percent. CTG score and Apgar score had good positive correlation with cord blood pH
( Spearman’s correlation coefficiemt = 0.486.030 and p=000,0,003 respectively). None of
the above tests is good as a screening test is foetal acidosis, systolic/ diastolic ratio of the
umbilical artery Doppler flow has no relationship with acute foetal acidosis when there is
no intra uterine growth restriction. Even after combining abnormal CTG with meconium
status of the amniotic fluid did not improve the ability to detect foetal acidosis. The Apgar
score and the CTG score correlated with cord arterial blood pH with a very high
significance.
