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PubMed This is a summary of 22 peer-reviewed journal articles Updated
Maternal-Fetal Medicine

How Are Intrauterine Blood Transfusions for Hydrops Done?

At a Glance

An intrauterine blood transfusion safely delivers red blood cells to a fetus in the womb to treat severe anemia and hydrops caused by Parvovirus B19. Guided by ultrasound, a specialist injects donor blood into the umbilical vein, giving the baby's body time to recover from the infection.

In this answer

3 sections

01

How Parvovirus B19 Causes Anemia and Hydrops

02

The Mechanics of the Procedure

03

Recovery, Frequency, and Survival Rates

Yes, a baby can receive a blood transfusion while still in the womb. This procedure is called an intrauterine blood transfusion (IUT) [1][2]. When non-immune hydrops fetalis is caused by severe fetal anemia—often triggered by infections like Parvovirus B19—an IUT can be a highly effective, life-saving intervention [3][4]. The transfusion replaces the baby’s missing red blood cells, which helps reverse the heart failure and fluid buildup (hydrops), giving the baby’s body time to recover from the virus [3][5].

How Parvovirus B19 Causes Anemia and Hydrops

Parvovirus B19 specifically targets the baby’s bone marrow, temporarily stopping the production of new red blood cells [6][7]. Without enough red blood cells to carry oxygen (severe anemia), the baby’s heart has to pump much harder to deliver oxygen to the body’s tissues [8]. This overexertion can lead to heart failure and the abnormal fluid accumulation characteristic of non-immune hydrops fetalis [8][3].

The Mechanics of the Procedure

An intrauterine transfusion is performed by maternal-fetal medicine specialists in specialized centers [1][9]. The process involves several highly coordinated steps:

  • Ultrasound Guidance and Diagnosis: The entire procedure is carefully guided by continuous high-resolution ultrasound. Doctors first measure the blood flow in the baby’s brain, specifically looking at the Middle Cerebral Artery Peak Systolic Velocity (MCA-PSV), which accurately detects how severe the anemia is [10][11].
  • Pain Management and Preventing Movement: A common fear for mothers is whether they or the baby will feel pain, or what happens if the baby moves. The mother typically receives local anesthesia to numb her abdomen [12]. The baby may also be given pain medication and a brief, safe medication (a paralytic) to temporarily stop them from moving, ensuring the needle stays exactly where it needs to be [12][2].
  • Umbilical Cord Access: Using the ultrasound image as a map, the specialist inserts a fine needle through the mother’s abdomen and uterus directly into the umbilical vein (the main blood vessel in the umbilical cord) [13][14]. This technique is known as intravascular transfusion or cordocentesis [13].
  • Alternative Access: If the baby is very small, early in gestation, or the umbilical cord is difficult to reach, the doctor may deliver the blood directly into the baby’s abdomen. This is called an intraperitoneal transfusion, where the red blood cells are absorbed into the baby’s bloodstream [13][15].
  • The Transfusion: Specially tested, processed, and matched donor red blood cells are slowly pushed through the needle. The fetal heart rate and blood flow are continuously monitored during the transfusion to ensure the baby handles the new fluid volume well [16][17].

Recovery, Frequency, and Survival Rates

When performed by experienced specialists, an IUT has excellent success rates for treating Parvovirus B19-induced anemia and hydrops [4][2].

  • Frequency of Transfusions: Unlike some other causes of fetal anemia (such as Rh incompatibility) that require repeated transfusions until birth, Parvovirus B19 typically only requires one or two procedures [18]. Once the virus clears, the baby’s bone marrow recovers and resumes making its own blood [3][5].
  • Reversing Hydrops: The transfusion acts as a vital bridge. By immediately treating the anemia, the heart doesn’t have to work as hard, which often allows the hydrops to reverse completely while the bone marrow recovers [3][5].
  • Maternal Recovery: Following the procedure, the mother is monitored for a few hours to ensure both her and the baby are stable, and most women can go home the same day [12][9].
  • Survival Rates: Achieving higher hemoglobin (red blood cell) levels after the first or second transfusion significantly improves survival [18]. Overall, children who receive these transfusions generally have a favorable long-term prognosis for normal development [19][20].
  • Potential Risks: Like any invasive procedure, an IUT carries risks. These include a dangerous drop in the baby’s heart rate (bradycardia), preterm labor, premature rupture of membranes, and procedure-related pregnancy loss [14][21]. The medical team continuously monitors the baby to respond immediately to any heart rate changes, which is why having this done at a highly specialized tertiary care center is critical [9][22].

Common questions in this guide

Will my baby or I feel pain during an intrauterine blood transfusion?
During the procedure, the mother receives local anesthesia to numb her abdomen. The baby is also given pain medication and a temporary paralytic to safely stop movement, ensuring the needle stays exactly where it needs to be.
How many blood transfusions will my baby need for Parvovirus B19?
Unlike other causes of fetal anemia that require repeated procedures, an infection from Parvovirus B19 typically only requires one or two transfusions. Once the virus clears, the baby's bone marrow usually recovers and resumes making its own blood.
What are the risks of an intrauterine blood transfusion?
While generally safe when performed by experienced specialists, risks include a dangerous drop in the baby's heart rate, preterm labor, premature water breaking, and pregnancy loss. The medical team continuously monitors the baby to respond immediately to any complications.
How does a blood transfusion help treat fetal hydrops?
The transfusion replaces the baby's missing red blood cells to immediately treat severe anemia. This reduces the severe strain on the baby's heart, which often allows the fluid buildup associated with hydrops to reverse completely.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Is my baby's hydrops definitely caused by anemia, and have you measured the MCA-PSV to confirm its severity?
  2. 2.How many intrauterine blood transfusions has this specific care team performed, and what are your center's success rates?
  3. 3.What is the plan for managing pain for me, and will the baby receive medication to prevent movement during the procedure?
  4. 4.What happens if the baby experiences a heart rate drop (bradycardia) during the transfusion, and how is your team prepared to handle it?
  5. 5.How long will I need to be monitored in the hospital after the procedure before I can go home?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

Related questions

Can Maternal Viral Infections Cause Hydrops Fetalis?Can Non-Immune Hydrops Fetalis Resolve on Its Own?Does Non-Immune Hydrops Fetalis Cause Premature Birth?How Are Fetal Arrhythmias Causing Hydrops Treated?What Are Long-Term Outcomes for NIHF Survivors?What Are the Symptoms of Mirror Syndrome vs Normal Swelling?What Does Idiopathic Non-Immune Hydrops Fetalis Mean?What Is a Thoracoamniotic Shunt for Fetal Hydrops?Immune vs. Non-Immune Hydrops: What Is the Difference?Will Non-Immune Hydrops Fetalis Happen Again?Why Do I Need Perinatal Palliative Care for NIHF?What to Expect Delivering a Baby With Hydrops Fetalis?Why Do I Need an Amniocentesis for Hydrops Fetalis?Why Use Whole Exome Sequencing for Hydrops Fetalis?

References

References (22)
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    Perinatal Outcome After Intrauterine Transfusion in Rh Isoimmunized Mothers.

    Potdar O, Narkhede HR, Satoskar PR

    Journal of obstetrics and gynaecology of India 2019; (69(2)):123-128 doi:10.1007/s13224-018-1108-6.

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    Intrauterine transfusion: Best practices, techniques, and evolving trends.

    Devlieger R, Vergote S, Van den Eede E, et al.

    Best practice & research. Clinical obstetrics & gynaecology 2026; (104()):102686 doi:10.1016/j.bpobgyn.2025.102686.

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    Maternal Parvovirus B19 Infection Causing First-Trimester Increased Nuchal Translucency and Fetal Hydrops.

    Grubman O, Hussain FN, Nelson Z, Brustman L

    Case reports in obstetrics and gynecology 2019; (2019()):3259760 doi:10.1155/2019/3259760.

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    Intrauterine transfusion in 103 fetuses with severe anemia caused by parvovirus infection. A multicenter retrospective study.

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    Detection of human parvovirus B19 DNA in 22% of 1815 cutaneous biopsies of a wide variety of dermatological conditions suggests viral persistence after primary infection and casts doubts on its pathogenic significance.

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    Perinatal outcomes of intrauterine transfusion for foetal anaemia due to red blood cell alloimmunisation.

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    Should optimal timing between two intrauterine transfusions be based on estimated daily decrease of hemoglobin or on measurement of fetal middle cerebral artery peak systolic velocity?

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    Intrauterine transfusion under fetal analgesia: the evaluation of perinatal outcomes.

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    Comparison of intrauterine transfusion techniques in hemolytic disease of the fetus and newborn.

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    Health-Related Quality of Life and Behavioral Functioning after Intrauterine Transfusion for Alloimmune Anemia.

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This page provides educational information about intrauterine blood transfusions. Always consult your maternal-fetal medicine specialist for medical advice tailored to your specific pregnancy.

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