Name of the Procedure:

Hemoglobin or RBCs, fetal, for fetomaternal hemorrhage; Rosette Test

Summary

The Rosette Test is a laboratory procedure used to detect fetal red blood cells (RBCs) in the mother's blood. This test helps identify if there has been a transfer of fetal blood into the maternal circulation, a condition known as fetomaternal hemorrhage.

Purpose

The Rosette Test is performed to detect fetomaternal hemorrhage, where fetal blood cells enter the maternal bloodstream. This condition can lead to complications such as anemia in the fetus and can impact the Rh compatibility between mother and baby. The test aims to identify the presence and extent of fetal RBCs in maternal blood.

Indications

• Suspected fetomaternal hemorrhage
• Trauma during pregnancy
• Elevated maternal serum alpha-fetoprotein (MSAFP)
• Abdominal pain or bleeding during pregnancy
• Following procedures like amniocentesis or external cephalic version
• Post-delivery, especially if the newborn is anemic or the mother is Rh-negative

Preparation

• No specific fasting or dietary restrictions are required.
• It may involve drawing a blood sample from the mother.
• Inform the healthcare provider of any medications or supplementation being taken.

Procedure Description

1. A blood sample is obtained from the mother.
2. The sample is mixed with an anti-D serum, which binds to Rh-positive fetal red blood cells.
3. Indicator cells are added to form rosettes around the fetal cells if they are present.

4. The mixture is then examined under a microscope to count the rosettes.

   The main tools and materials used include collection tubes, anti-D serum, indicator cells, a microscope, and laboratory reagents.

Duration

The procedure typically takes a few hours, including the time taken to prepare and analyze the sample.

Setting

The procedure is performed in a diagnostic laboratory.

Personnel

• A phlebotomist or nurse to draw the blood sample.
• A laboratory technician or medical technologist to perform the test and analyze the results.
• A physician or specialist to interpret the results.

Risks and Complications

• The risks are minimal and primarily associated with the blood draw, including slight pain, bruising, or infection at the site of puncture.
• False positives or negatives can occur, necessitating follow-up testing.

Benefits

• Early detection of fetomaternal hemorrhage.
• Helps in preventing and managing Rh incompatibility and its complications.
• Aids in decision-making regarding treatments like antenatal Rh immunoglobulin administration.

Recovery

• No significant recovery time is involved.
• The patient can resume normal activities immediately after the blood draw.
• Any specific follow-up instructions will depend on the test results.

Alternatives

• Kleihauer-Betke test: Another blood test used to detect fetal red blood cells in the maternal circulation.
• Flow cytometry: A more detailed and quantitative test to measure the presence of fetal cells.

Each alternative has varying levels of sensitivity and specificity, and the choice depends on the clinical scenario and available resources.

Patient Experience

• Patients might feel a brief sharp pinprick during the blood draw.
• Minimal discomfort post-procedure.
• Anxiety or concern while waiting for the results, which can be alleviated with proper counseling by healthcare providers.
• Pain management is generally not necessary, as the procedure is relatively non-invasive.