The Blood Service now provides Non-Invasive Prenatal Analysis (NIPA) for blood group genotyping to determine the RhD status of the fetus.
This new service will aid in assessing pregnancies at risk of Haemolytic Disease of the Fetus and Newborn (HDFN) and help guide clinical management.
NIPA avoids the requirement for amniocentesis as it is now possible to extract cell-free fetal DNA (ffDNA) from the peripheral blood of the mother and analyse it for the presence of the RHD gene.
This test will complement the anti-D quantitation and intrauterine transfusion support that the Blood Service already provides for the management of pregnancies at risk of HDFN.
The NIPA service will be available to RhD negative pregnant women who fall into one of the following three categories:
1. Alloimmunised (maternal anti-D)
2. Following severe fetomaternal haemorrhage during pregnancy, or intrauterine fetal death
3. A relative contraindication to routine antenatal Anti-D prophylaxis, where the fetal RhD genotype result will guide anti-D prophylaxis decisions e.g. prior allergic reaction to RhD-Ig, or cultural/religious beliefs.
NIPA testing can be performed from 12 weeks gestation and will require two additional EDTA blood samples to be collected for testing. Samples must arrive at the Blood Service within 72 hours of collection.
The NIPA service will improve clinical practice in transfusion medicine by giving clinicians an additional diagnostic marker to guide them in determining the appropriate management of a high-risk pregnancy.
NIPA will reduce the stress and trauma on the mother as it eliminates the need for more invasive and risky sampling procedures.
This is particularly helpful for women with a complicated obstetric history who can be informed as early as 12 weeks gestation whether or not their pregnancy will be at risk due to HDFN.
For more information please see the NIPA for Blood Group Genotyping Information Sheet which can be found here.