Blood Transfusion for a Premature Baby

Anaemia of prematurity, in plain terms

Bliss defines anaemia as too little haemoglobin in the blood, and haemoglobin as the chemical carried by red blood cells that transports oxygen. If there is not enough of it, the body may not get enough oxygen. In a preterm baby three things push in the same direction at once.

• Iron is transferred from mother to baby mainly in the last weeks of pregnancy, and a baby born early simply misses part of that.
• The switch from making red cells in the womb to making them afterwards has a natural dip, and it is deeper and earlier in preterm babies.
• Preterm babies grow very fast relative to their size, so blood volume has to keep expanding.

And the fourth reason, which is us

Bliss states it plainly: sometimes a baby needs multiple blood samples over a short period, and this might mean they need a transfusion to replace the blood used for testing. In the first weeks, for a very small baby, the volume taken for monitoring is not trivial relative to the volume they have. This is a known cost of intensive care rather than an accident, and it is one reason teams batch tests, use the smallest sample tubes available, and take blood from an existing line where possible.

What a transfusion is

Bliss describes a blood transfusion as extra blood given from a donor, and lists severe anaemia, low blood pressure, and surgery as the situations where one might be needed. In neonatal practice it usually means a small measured volume of donor red cells given slowly through a line or cannula over a few hours, while your baby is monitored. Most babies sleep through it. Nothing about the rest of the day's care usually changes.

Consent and the conversation you should get

A transfusion is a treatment your team should discuss with you before it happens, other than in an emergency. NICE guideline NG124 tells neonatal teams to give parents explanations and regular updates about their baby's condition and treatment, especially when there are changes, and to support those discussions with written information. If a transfusion is planned, it is entirely reasonable to ask why now, what the haemoglobin level is, what the alternative is, and what the risks are. UK donor blood for neonates is screened and specially prepared, and your team can explain the specific safeguards used.

Platelet transfusions are a different thing

Bliss notes that platelets are important for controlling bleeding, that the count can be too low in preterm and sick babies, and that if the level gets too low a baby might need a platelet transfusion. That is a separate product given for a separate reason, so a platelet transfusion is not a "second blood transfusion" even though it looks similar at the cot side.

Exchange transfusion is also different

Bliss defines exchange transfusion as replacing a baby's blood with blood from an adult donor, done when a baby's jaundice level is very high and not improving with treatment. It is a much bigger procedure than a simple top-up transfusion and is uncommon. If somebody uses the phrase, ask which one they mean, because the two get confused constantly.

What happens afterwards

Some babies need one transfusion; some need several over the first weeks; many need none at all. As the frequency of blood tests falls and your baby starts producing red cells more efficiently, the need usually disappears. Iron supplements are started for most preterm babies once milk feeds are established, and continued for months after discharge, because milk alone does not replace the iron stores that would have been laid down in the last weeks of pregnancy. Your baby's team and, later, your GP should be clear about how long to continue them.

What to ask

Three questions cover it. What is the haemoglobin now, and what level would prompt a transfusion? Is any of the drop being driven by sampling, and can any tests be batched or dropped? And is my baby on iron, from when, and for how long after we go home? The last one is the question most likely to get lost at discharge, and it is the one that matters for the following six months.

What you might notice, and what you probably will not

Anaemia in a preterm baby is often silent. Where there are signs, they tend to be non-specific: a baby who tires more quickly during feeds, has more pauses in breathing or dips in oxygen, looks paler, or whose heart rate sits higher than usual. None of these is diagnostic on its own, which is why haemoglobin is measured rather than judged by eye.

After a transfusion, some parents describe a baby who feeds better or dips less within a day or two. That is a reasonable thing to notice and not something to expect or to be disappointed by.

Where the blood comes from

Donor blood in the UK is given voluntarily, screened and prepared specifically for babies, in small volumes with careful matching and additional processing. If you have questions about the product itself, your baby's team can answer them and can ask the hospital transfusion laboratory on your behalf. Parents with religious or personal objections to transfusion should raise them early rather than in an emergency; teams are used to having that conversation properly and there is time to have it well.

The thing that most often gets missed at discharge

Iron. Preterm babies usually go home on an iron supplement and often on vitamins, and the plan for how long to continue can fall between the neonatal unit and the GP. Bliss's nutrition guidance for preterm babies covers the extra requirements that milk alone does not meet. Ask for the plan in writing, and check it is on your GP's repeat list before you run out.