Thousands of families have been stunned to discover that a widely-prescribed nausea drug may increase the risk of congenital heart defects, including “cardiac septal defects” like atrial septal defect. Still more shocking is that the drug in question, Zofran, has been America’s most popular morning sickness treatment for almost a decade.
Zofran Increases Atrial Septal Defect Risk 200%, Studies Find
Because morning sickness usually strikes in early pregnancy, women are most likely to be prescribed Zofran, a drug never approved for use during pregnancy, during the first trimester. At this point, fetal tissues are just beginning to form, and researchers believe that this early exposure may cause some alteration in the way heart tissues develop.
In 2013, a group of scientists in Denmark reviewed every birth record logged in the country from 1997 to 2010. Denmark maintains rigorous prescription records, too, and the researchers were able to figure out which pregnant women had been prescribed Zofran during early pregnancy. Then they ran the numbers, investigating whether women who had been exposed to Zofran were more likely to deliver children with birth defects. They were. Women prescribed Zofran were more than twice as likely to have babies with an atrial septal defect.
Swedish researchers performed a very similar study, using the birth and prescription records from every pregnancy in Sweden between 1998 and 2012. Unfortunately, their study didn’t break down the relative likelihood of specific birth defects, but they found that women who took Zofran were 2.05 times more likely to deliver children with cardiac septal defects.
What Is Atrial Septal Defect?
Widely believed to be the most common congenital heart defect, atrial septal defect involves a hole, either large or small, in the wall between a child’s right and left atrium, the two uppermost chambers of the heart.
In healthy human hearts, a complete barrier sits between these two chambers, preventing the possibility of blood flowing from one to the other. As we can see in the diagram above, atrial septal defects allow blood to flow directly from the left atrium to the right, since the heart’s left side is slightly higher than its right side and gravity draws fluids downward inside the body. Improper blood flow of this nature impairs the heart’s ability to oxygenate blood and then deliver that oxygenated blood to the cells and tissues that need it.
Blood takes a complex pathway through the body. Usually, blood enters the right atrium, pumps down to the right ventricle and then passes out to lungs. After picking up oxygen in the lungs, blood returns to the heart, but this time it enters through the left atrium. From there, it travels down to the left ventricle and is then pumped out toward the rest of the body.
With an atrial septal defect, blood can go straight from the left atrium to the right atrium. But remember that blood in the left atrium has already been to the lungs, and its already picked up a lot of oxygen. Shunted over to the right atrium, this oxygenated blood goes back to the lungs for a second time, but the return visit is practically useless since the blood already has all the oxygen it can carry. The body, meanwhile, is receiving only a portion of the blood it needs, since much of the fluid is leaking where it shouldn’t go.
What Are Its Symptoms?
Babies usually don’t experience any symptoms at first, since most atrial septal defects are small and affect blood flow in relatively minor ways at first. That’s not always the case, and some larger ASDs will require immediate treatment.
In either case, most atrial septal defects cause respiratory problems initially, since the heart is intimately tied to lung function. Difficulty breathing is a common symptom, and children with ASD may be at an increased risk for lung infections.
Over time, the effects of even small atrial septal defects usually become apparent. Adults with ASD generally begin experiencing problems around the age of 30, according to the Mayo Clinic, symptoms like:
- shortness of breath
- swollen legs
- heart rhythm problems (50% to 60% of ASD patients over 40 develop atrial fibrillation, a form of arrythmia, the Cleveland Clinic reports)
There’s also good evidence that atrial septal defects increase the risk of stroke. But many of the defect’s long-term complications involve how the heart reacts to the improper blood flow caused by an ASD. Because the body is receiving so little blood, the heart is forced to pump harder, at higher pressures, than normal. This can make the organ’s right side grow larger; its muscular walls literally thicken, usually only on the right side. While this enlargement is a “quick fix” to the blood flow problem, it can eventually lead to heart failure.
Pulmonary hypertension, high blood pressure in the lungs, is also common. This condition can actually reverse the flow of blood in the heart. Rather than flowing from left to right through the ASD, patients with large ASDs and very serious pulmonary hypertension can have blood flow from the right to the left.
Can It Be Cured?
Small defects of this sort can close of their own accord within the first few weeks of life, but larger holes are associated with serious complications, including life-long alterations to the organ’s structure and functioning.
Thankfully, surgeons can successfully repair even large atrial septal defects in all but the rarest circumstances. Most common is a type of procedure known as “cardiac catheterization,” in which a thin tube is thread upwards through a vein in the leg or groin. After reaching the heart, a small patch can be applied to close the atrial septal defect.
Open heart surgery is rare for ASDs, but may be necessary to repair large defects.
What Causes Atrial Septal Defect?
While only 1 out of every 2,034 babies will be born with the condition, atrial septal defect (ASD) remains one of America’s most common congenital abnormalities. ASD can occur on its own or as one feature of several genetic syndromes, including:
- Down syndrome
- DiGeorge syndrome
- Ellis-Van Creveld syndrome
Tetralogy of Fallot, a cluster of four characteristic heart defects, usually includes an atrial septal defect as one of its features, although it is not itself considered a genetic syndrome.
Researchers believe genetic mutations play a part in most birth defects, but also acknowledge the important role of environmental factors, like chemical toxins, in causing these sort of abnormalities. Prescription drugs can also impair the development of fetal heart tissues. As we’ve seen, medical researchers have suggested that Zofran may be one such prescription drug.
My Child Was Born With Atrial Septal Defect. Can I File A Zofran Lawsuit?
Yes, any parent who was prescribed Zofran during the first trimester and then delivered a baby with atrial septal defect may be able to file suit.