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Haemolytic disease of the fetus and newborn

Also called Rhesus disease or HDFN

Haemolytic disease of the fetus and newborn (HDFN), often called rhesus disease, happens when antibodies from a pregnant woman cross the placenta and destroy the baby's red blood cells. It most often happens when the mother is RhD negative and the baby is RhD positive, usually in a later pregnancy.

Last updated Nov 9, 2026

What it is

It can cause anaemia and jaundice in the baby and, in severe cases, can be life-threatening.

Routine blood tests in pregnancy and anti-D injections for RhD negative mothers prevent most cases. Affected babies may need light therapy or blood transfusions.

Common signs

  • Usually found through blood tests in pregnancy
  • In the baby: yellow skin (jaundice) and anaemia
  • Swelling in the baby, in severe cases

How it is usually diagnosed

  • Blood group and antibody tests in pregnancy
  • Ultrasound scans to check the baby
  • Blood tests on the baby after birth

Records worth keeping

Keeping these together makes each appointment easier, especially when you see a new doctor:

  • Blood group and antibody results
  • Anti-D injection dates
  • Pregnancy scan reports
  • Baby blood test results and discharge letters

Questions to ask your doctor

  • Am I RhD negative?
  • When will I need anti-D?
  • How will my baby be monitored?

When to get help right away

Call 112 or go to the nearest emergency department if you have:

  • A baby who is very yellow, sleepy or not feeding well: get urgent medical help

This page is general information. It is not a diagnosis and does not replace a doctor who knows your history. Medfold keeps your records organised; it does not interpret them.

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