Foetal acid-base status in clinical foetal distress and high risk casesThe material in this paper has been taken from an M.D. Thesis submitted to the University of Hong Kong.

Abstract

SummaryThe acid-base balance in 307 Chinese patients in labour was studied in Tsan Yuk Hospital, Hong Kong over a 15-month period. Fifty-six of these were normal cases, 200 cases exhibited clinical signs of foetal distress and the other fifty-one were high risk cases. The results showed that cases of clinical foetal distress had a significantly lower foetal pH than that in the normal control group. Of the different signs of clinical foetal distress, meconium was the least important and foetal tachycardia appeared to be more significant than the others. Cases of postmaturity and uterine inertia also gave a lower foetal pH than normal. It is concluded that foetal blood sampling is indicated in these types of cases.

Maternal and fetal acid-base chemistry: A major determinant of perinatal outcome

“…[1224] For confirmatory interpretation of the findings, it may have to be combined with fetal blood gas analysis. However, FBS still remains superior to cardiotocography (CTG) alone as it provides direct information about the fetal acid-base balance and gives a more accurate picture of the state of the fetus.…”

“…Fetal distress: It is well evidenced[41524] that in clinical fetal distress, there is a significantly lower fetal pH than that in normal fetuses.Post-maturity: Cases of post-maturity also gave a lower fetal pH than normal. [24]…”

“…[ 23 ] Some of the leading conditions based on which pregnancies are categorized as high risk are presented in Table 2 and these listed conditions are the indications for elective fetal blood sampling (FBS) in labor. [ 24 ] Additionally, it should be noted that there are also clinical parameters for which fetuses of normal pregnancies are subjected to FBS in labor and these are equally presented in Table 2 . Biochemical monitoring revealed that during labor all patients showed a gradual fall in fetal pH and an increase in pCO 2 and base deficit, especially in the second stage of labor and during delivery.…”

Correlation between the foetal acid-base status and the Apgar scoreThe material in this paper has been taken from an M.D. Thesis submitted to the University of Hong Kong.

“…Fifty-six of these were normal cases, 200 showed clinical signs of foetal distress and the remaining fifty-one were high risk cases. The details of the acid-base status of this series have been reported separately (Lee, 1972b). A total of 206 cases were delivered within 3 hr after the last foetal blood sample was collected.…”

“…Correlation between the foetal pH and the Apgar score by previous workers has not given consistent results (Beard, Morris & Clayton, 1967;Paul, Gare & Whetham, 1967;Haworth, Milic & Adamson, 1968; Hon, Khazin & Paul, 1969;Lumley & Wood, 1969;Galloway, 1970). This has been attributed by Beard (1970) (Lee, 1972b The mean acid-base values for each of the groups A, X and Y are shown in Table 1. The mean foetal pH in group A was 7.28 and the mean maternal pH 7-38.…”