Fetal Blood Sampling (FBS) is a useful tool for the diagnosis of fetal distress. The fetal scalp is first visualised with an amnioscope inserted vaginally and the scalp is cleaned. The sample is taken form a small cut made in the scalp from which blood is collected in a microtube (1)(2).

Fetal Blood Sampling. Adapted from (1).

The blood sample should be immediately analysed for pH and base excess. If the pH is less than 7.2 there is significant hypoxia and the baby should be delivered by the fastest means possible (1)(2).