Leeds Fetal Medicine Unit Website

Fetal Blood Sampling (FBS) and transfusion

In rare circumstances it is necessary to obtain fetal blood cells rather than other types of fetal tissue, this is particularly the case when the baby may be thought to have anaemia (a deficiency of red blood cell haemaglobin), often a result of incompatibility between maternal and fetal blood cell types. Like amniocentesis and CVS, FBS is done under direct ultrasound guidance and following an injection of local anaesthetic to numb the mothers skin a thin needle is inserted into the umbilical vein where it inserts into the placenta. Pancuronium is then given to temporarily immobolise the fetus. A small amount of blood is then taken and rapidly analysed to assess anaemia whilst the needle is left in place. If the analysis shows that the baby is anaemic then a transfusion of blood can then be given via the same needle that blood was taken out of.

FBS are performed less commonly than other invasive procedures in Leeds (see Recent FBS outcome data), but can be potentially life saving. Published studies suggest a of 1% chance of fetal loss per procedure (an anaemic fetus may require several transfusions through the pregnancy)

Picture (to follow)

pdf information sheet (to follow)

Transfusion of irradiated blood information for patients (please click here)

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