Lessons learned from the implementation of non-invasive fetal RHD screening

ABSTRACT

Introduction: In the fight against hemolytic disease of the fetus and newborn, pregnant RhD negative women are offered antenatal and postnatal anti-D immunoglobulin prophylaxis to prevent the development of antibodies against the fetal D antigen. Antenatal prophylaxis has traditionally been provided to all D negative pregnant women, as the fetal RhD type remains unknown until birth. With noninvasive prenatal testing of cell-free DNA, predicting the fetal RhD type has become highly feasible based on analysis of the fetal RHD gene. Fetal RHD screening can guide targeted antenatal prophylaxis, treating only women who carry an RhD positive fetus, thereby avoiding the unnecessary treatment of approximately 40% of the RhD negative women.

Areas covered: Areas covered are the current clinical practice, performance, and challenges of fetal RHD screening, and relevant issues for its implementation.

Expert commentary: Fetal RHD screening is highly accurate, with sensitivities of 99.9%, as reported from clinical programs. From gestational week 10, sensitivities are approximately 99%. Despite challenges in assay design, low levels of cell-free fetal DNA in the maternal plasma, and concerns regarding implementation and medical necessity, the clinical experience with fetal RHD screening and targeted prophylaxis has generated encouraging results, and its future widespread use is expected.

KEYWORDS:

• Fetal RHD screening
• cell-free fetal DNA
• HDFN
• antenatal prophylaxis
• noninvasive prenatal testing

Declaration of interest

The Department of Clinical Immunology, Copenhagen University Hospital, has sponsored the expenses for language revision by American Journal Experts. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.