What is cystic hygroma (lymphatic malformation)?
Cystic hygroma is a condition caused by a problem in the lymphatic system that can be seen at any point in pregnancy but most commonly in the first trimester. It is also called lymphatic malformation, lymphangioma or venolymphatic malformation. Fetuses with this condition have atypical skin thickening, usually at the back of the neck. In more severe cases, thickening can occur along the entire length of the body.
These unborn babies also have thin membranes (called septations) that extend from the skin into the underlying tissue, forming cysts under the skin. These changes may be visible during an abdominal or vaginal ultrasound you have during early pregnancy. They are also visible on ultrasound around 18 to 20 weeks of pregnancy.
What are the complications of cystic hygroma?
The concern with cystic hygroma in early pregnancy is not the cystic hygroma itself, but other problems that may come with it.
Up to 50% of fetuses with cystic hygroma in early pregnancy also have an abnormal number of chromosomes. Chromosomes are the genetic blueprint of the developing fetus. When a baby has too many, too few or duplicate chromosomes, they develop disorders such as Down syndrome, Trisomy 13 or 18 or Turner syndrome. Chromosomal abnormalities often result in miscarriage during the first trimester.
A diagnosis of cystic hygroma also increases the risk of other conditions. The fetus’s heart, skeleton or other organs may not develop properly. In the most severe cases, the fetus may develop fetal hydrops — a dangerous accumulation of fluid around the heart, lungs or in the skin.
How common is cystic hygroma?
Cystic hygroma is most commonly seen in early pregnancy. This condition is frequently diagnosed in the first trimester and affects about 1 in every 285 pregnancies.
What are the signs of cystic hygroma?
Fetuses with cystic hygroma diagnosed in early pregnancy have significantly thickened skin. They also have thin membranes (septations) extending from the skin into the subcutaneous tissues below. On an ultrasound, these are clearly visible as multiple cysts.
What tests are used to diagnose cystic hygroma?
Your obstetrician (OB) or maternal-fetal medicine (MFM) specialist may recognize and diagnose cystic hygroma during a routine 10-to 12-week ultrasound. A vaginal ultrasound typically produces clearer images at this stage of pregnancy. The thickened skin and septations of cystic hygroma are visible during an early ultrasound.
About half of babies diagnosed with cystic hygroma also have chromosomal abnormalities. If an ultrasound shows cystic hygroma in early pregnancy, your doctor will discuss prenatal genetic diagnostic testing.
Our maternal-fetal medicine specialists perform two types of genetic diagnostic testing:
- Chorionic villus sampling (CVS) can be done before 14 weeks of pregnancy.
- Amniocentesis can be done after 16 weeks.
What can I expect after a diagnosis of cystic hygroma?
If you’re diagnosed with cystic hygroma, the MFM and genetic experts at our Colorado Fetal Care Center will monitor your pregnancy more closely. You will have a detailed fetal ultrasound at 16 to 20 weeks gestation to check for any problems in your baby’s developing heart or skeleton, and follow-up ultrasounds during the remainder of your pregnancy as recommended. We will also perform a fetal echocardiogram to see more precise images of your baby’s heart.
How is cystic hygroma treated during pregnancy?
Treating cystic hygroma during pregnancy involves diagnosing and monitoring the fetus with imaging and genetic tests. There is no available treatment for this condition in the womb.
How is cystic hygroma treated in a newborn?
If your baby is born with chromosomal, heart or skeletal abnormalities, they may need special care. If their condition requires additional treatment, our Neonatal Intensive Care Unit (NICU) offers the advanced support they need, which is tailored to each baby’s needs.
Why choose us for treatment of cystic hygroma?
Our maternal-fetal medicine and genetics specialists are experts at caring for expectant mothers with high-risk pregnancies. Our team also includes specially trained fetal radiologists and sonographers experienced in diagnosing cystic hygroma. We offer specialized prenatal genetic testing to make sure you get an accurate diagnosis and a care plan tailored to your family’s unique needs.
The Colorado Fetal Care Center is at the forefront of treatment and care for this condition. Our talented and compassionate team will help you and your family navigate this diagnosis and help you have a healthy delivery.