Hypoplastic left heart syndrome (HLHS) is a problem with the
heart’s structure that is present at birth (congenital). It is a
group of related defects that, together, mean that the left side of
the heart is underdeveloped. Normally, oxygen-poor blood is pumped
through the right side of the heart to the lungs, where it gains
oxygen and returns to the left side of the heart. The oxygen-rich
blood is then pumped from the left side of the heart to the rest of
the body. At birth, all babies also have two connections, or shunts,
between the two sides of the heart; however, within a few days of
birth these connections close.
Among people with HLHS, the underdeveloped left side of the heart is
unable to provide enough blood flow to the body. The normal shunts
present at birth help to direct blood to the body; when these
connections close the oxygen-rich blood supply decreases. Thus,
babies with HLHS might look normal at birth, but will develop
symptoms of HLHS within a few days. These symptoms might include:
- Poor feeding
- Problems breathing
- Pounding heart
- Weak pulse
- Ashen or bluish skin color
To learn more about HLHS click on one of the following links or
scroll down the page.
What We Know About Hypoplastic Left
Heart Syndrome
- How often does hypoplastic left heart syndrome occur?
- What problems do people with hypoplastic left heart syndrome
have?
What We Still Do Not Know About
Hypoplastic Left Heart Syndrome
- What causes hypoplastic left heart syndrome?
- Can hypoplastic left heart syndrome be prevented?
Resources for Families and Individuals
Affected by Hypoplastic Left Heart Syndrome
| What
We Know About Hypoplastic Left Heart Syndrome |
How often does hypoplastic left heart syndrome occur?
CDC estimates that each year about 975 babies in the United
States are born with hypoplastic left heart syndrome (HLHS) (1). In
other words, each year about 2 out of every 10,000 babies born will
be born with HLHS.
What problems do people with hypoplastic left heart syndrome
have?
Without treatment, babies with HLHS die. Although this defect
cannot be corrected, surgeries after birth can create the needed
connections, or shunts, to allow the blood to get to the body. The
right side of the heart, which normally only pumps blood to the
lungs, now must provide the blood flow to both the lungs and the
body. This extra work eventually weakens the heart. Children with
HLHS require regular follow-up visits with a cardiologist throughout
their lives, and can develop problems as they grow.
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| What
We Still Do Not Know About Hypoplastic Left Heart Syndrome |
What causes hypoplastic left heart syndrome?
There is no known cause for hypoplastic left heart syndrome
(HLHS). The problem develops before birth when there is not enough
growth of the left side of the heart.
We at CDC work with many other researchers to study risk factors
that can increase the chance of having a baby with HLHS, as well as
outcomes of babies with the defect. Following are examples of what
our research has found:
- The rate of HLHS has been increasing from year to year (2).
- There is a higher risk for HLHS among White babies than
among babies of other races or ethnicities (2).
- No strong link exists between caffeine use by a mother and
risk for HLHS (3).
- Multivitamin use by mothers before and during pregnancy can
decrease the risk for HLHS (4).
Can hypoplastic left heart syndrome be prevented?
HLHS is a congenital hear defect, meaning it is present at birth.
As such, HLHS cannot be prevented. Even so, mothers can take steps
before and during pregnancy to have a healthy pregnancy. Steps
include taking a daily multivitamin with folic acid (400
micrograms), not smoking, and not drinking alcohol during pregnancy.
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|
Resources for Families and Individuals Affected by
Hypoplastic Left Heart Syndrome |
American Heart Association
Mayo Clinic
Medline
References
- Canfield MA, Honein MA, Yuskiv N, Xing J, Mai CT, Collins
JS, et al. National estimates and race/ethnic-specific variation
of selected birth defects in the United States, 1999-2001. Birth
Defects Res Part A Clin Mol Teratol. 2006;76(11):747–56.
- Botto LB, Correa A, Erickson JD. Racial and temporal
variations in the prevalence of heart defects. Pediatrics. 2001;
107(3):1-8
- Browne ML, Bell EM, Druschel CM, Gensburg LJ, Mitchell AA,
Lin AE, et al. Maternal caffeine consumption and risk of
cardiovascular malformation. Birth Defects Res A. 2007;
79:533-43.
- Botto LD, Mulinaire J, Erickson JD. Occurrence of congenital
heart defects in relation to maternal multivitamin use. Am J
Epidemiol. 2000; 151(9):878-84.
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Date:
March 11, 2009
Content source: National Center on Birth Defects and Developmental
Disabilities
