A rare condition with potentially devastating complications
Neonatal lupus erythematosus (NLE) occurs in 2-6% of offspring of mothers who have SSA/SSB antibodies, not just the offspring of mothers with lupus erythematosus.
A blood test can determine if the mother has SSA/SSB antibodies and if her fetus is at risk of NLE
The SSA/SSB antibodies enter the fetal circulation as early as 17 weeks of gestation and can lead to permanent destruction of the electrical conduction system and/or damage to the fetal heart muscle. The highest risk period of developing these cardiac problems is 19-24 weeks of gestation
Damage to the conduction system is called atrioventricular (AV) block. The SSA/SSB antibodies damage or destroy the electrical connection between top (atria) and bottom chambers (ventricles).
Second degree AV block occurs when the electrical connection is damaged but not destroyed so some of the atrial impulses are relayed to the ventricles and others are not This will result in an irregular rhythm or skipped beats.
Regular Heart Sound
Irregular Heart Sound
Irregular Heart Sound (2)
Third degree or complete AV block results when the electrical connection is destroyed and the atria beat at the normal rate (120-160 beats per minute), while the ventricles beat at a very slow rate (70-50 beats per minute)
Complete AV block can cause heart failure before the baby is born leading to premature delivery or in 16-20%, death before 1 year of age.
Complete AV block is permanent; the only treatment is a life-long pacemaker inserted through the baby’s chest after birth (animated picture of a pacemaker). No treatment once the AV block is complete will restore normal rhythm either before or after birth.
In fetal life, AV block can developOVERNIGHT!
There is hope: in some cases detecting and treating AV block before it is complete may halt the progression and restore sinus rhythm.
But we don’t know for sure if this is true because AV block has been detected early enough to treat in only a very few cases.
Why we are doing this reseach study? Part 2: To detect fetal AV block before it is complete
Previous studies using cardiac ultrasound (fetal echocardiography) done every week failed to detect AV block in its early stages
We have a simple method that we believe will detect fetal AV block before it is complete. And we need your help to see if this is true. We call the research study of this method, ‘Heart Sounds at Home’