EFM Fetal Oxygenation and Acid-Base Balance 3

Question 1

Fetal hemoglobin (HbF) differs from adult hemoglobin (HbA) in that HbF:

Accepted Answer

Has a higher affinity for oxygen at any given PO2

Answer

Fetal hemoglobin has a higher oxygen affinity than adult hemoglobin because it binds 2,3-DPG less effectively, allowing more efficient oxygen extraction from maternal blood at the placenta.

Question 2

The oxyhemoglobin dissociation curve is shifted to the RIGHT in fetal blood compared to maternal blood, meaning:

Accepted Answer

Fetal hemoglobin loads oxygen more easily at the placenta

Answer

A leftward shift (not rightward) of fetal HbF means it loads oxygen more readily at the placenta; stating a rightward shift relative to maternal blood is incorrect — HbF curve is actually left-shifted, meaning higher affinity.

Question 3

The normal umbilical vein pH at delivery is approximately:

Accepted Answer

7.32 – 7.43

Answer

Normal umbilical vein pH is 7.32–7.43, reflecting oxygenated blood returning from the placenta with better acid-base status than umbilical artery blood.

Question 4

Which condition best describes fetal asphyxia?

Accepted Answer

Hypoxia with significant metabolic acidosis and risk of organ damage

Answer

Fetal asphyxia is a severe condition combining hypoxia with metabolic acidosis (significant base deficit) that places the fetus at risk for end-organ damage including brain injury.

Question 5

Cord blood gas sampling is most indicated when:

Accepted Answer

There are concerns about fetal well-being during labor or delivery

Answer

Cord blood gases are indicated when there are concerns about fetal well-being (e.g., non-reassuring FHR pattern, low Apgar scores, meconium-stained fluid) to objectively assess fetal acid-base status at delivery.

EFM - Electronic Fetal Monitoring Practice Test

EFM - Electronic Fetal Monitoring Practice Test

EFM Fetal Oxygenation and Acid-Base Balance 3