What is fetal blood sampling?

Fetal blood sampling (FBS) is a procedure where a small drop of blood is taken from the top of the baby’s head during labour; it is similar to a blood test taken with a thumb or heel prick. When the baby‘s heart rate is being monitored closely and there are concerns about how the baby is coping with labour, the CTG machine can tell midwives and doctors that there may be a problem. However, the CTG doesn’t always give enough information to suggest whether the baby is distressed due to a lack of oxygen. To get a clearer picture of how well the baby is coping with labour, a small sample of blood is taken; this is quickly analysed and the result is back within minutes. The results of the FBS will indicate whether the baby needs delivering straight away by caesarean, ventouse or forceps, or if the baby is coping well with labour.

If the FBS results are satisfactory but the baby’s heart rate is still of concern the test may be repeated 30 minutes later. If in the meantime baby’s heart rate returns to normal, a further FBS may not be required. When the baby is born you may notice a small scratch on top of the baby’s head, this usually heals within a few days and rarely hurts the baby.