What is fetal distress?

Fetal distress is the term commonly used to describe fetal hypoxia. It is a clinical diagnosis made by indirect methods and should be defined as:-

Hypoxia that may result in fetal damage or death if not reversed or the fetus delivered immediately.

More commonly a fetal scalp pH of less than 7.2 is used to indicate distress (1)(2).

What can cause Fetal Distress?

There are potentially limitless causes for fetal distress but several key mechanisms are usually involved. Contractions reduce temporarily placental blood flow and can compress the umbilical cord. If a women is in labour longer then this can cause fetal distress via the above mechanism (1)(3).

Acute distress can be a result of placental abruption, prolapse of the umbilical cord (especially with breech presentations), hypertonic uterine states and the use of oxytocin (1).

Hypotension can be caused by either epidural anaesthesia or the supine position, which reduces inferior vena cava return of blood to the heart. The decreased blood flow in hypotension can be a cause of fetal distress (1).

Which babies are at risk of Fetal Distress?

Any baby can run the risk of becoming distressed but there are indications for increased fetal monitoring. Long labour, the presence of Meconium and the use of epidurals or oxytocin all would suggest the need for more monitoring (1)(2)(3).