Blood ordering practices in obstetric units in the United Kingdom.

A postal questionnaire on blood ordering practices and blood availability was sent to 89 randomly selected maternity units within the United Kingdom. The replies demonstrated a wide variation in crossmatching practices. Of those units that replied, 56% crossmatch for elective and 64% for emergency Caesarean section, 54% for manual removal of placenta, and 29% for fetal distress in labour. The remainder 'group and screen' for these indications. Lack of 24 h cover by a resident haematology technician, and location of blood banks distant to the obstetric unit were associated with significant delays in blood availability. More extensive use of the 'group and screen' technique may reduce unnecessary crossmatching without jeopardizing patient safety, and is advocated for maternity units.