Fetal scalp pH .
|a.||a result of 7.28 is normal||True|
|b.||accurately determines the condition of the baby||False|
|c.||carries no risk||False|
|d.||cannot be performed in breech presentation||True|
|e.||reduces the Caesarean section rate in patients having continuous electronic fetal heart rate monitoring||True|
(See also MCQ Paper 2, question 42).
The lower limit of normal is usually taken as 7.2 and levels below this are normally grounds for immediate delivery.
Levels > 7.25 give reasonable reassurance that the baby is still in good condition.
Some babies with pH measurements better than 7.2 will be born in need of resuscitation.
The bottom line is that
we have no perfect method of assessing the condition of the baby.
Electronic monitoring tends to increase Caesarean section rates.
The use of scalp pH
measurement goes some way to counterbalancing this.
pH measurements can be done in breech presentation: you can get blood from the buttock.
The semantically pure would argue that this is not a “scalp” pH, so answer “true” to question d!
If the question had been “pH cannot be measured in breech presentation” the answer would have been “false”.
In practice, we tend to go for Caesarean section if any complication arises in labour with planned vaginal breech delivery.
An abnormal fetal heart rate pattern would fall into this category.
So pH measurement from the buttock is rarely, if ever, done.
|Return to MCQ Paper 2, answer 42. "Fetal distress"|
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