Conditions We Care For

We regularly help families whose developing baby has 1 or more prenatal conditions, including rare conditions that many doctors never see. These are some of the many conditions we diagnose and treat:

• Abdominal wall defects

  Abdominal wall defects happen when a baby’s belly (abdomen) does not fully form during pregnancy. This causes a hole in the muscles and skin that cover the baby’s belly. There are 2 main types. Gastroschisis is when a baby’s intestines are outside the body without any covering. An omphalocele is a gap in the muscles and skin, with a sac over the organs that stick out of the body. We see many babies with these abdominal wall defects.

• Alloimmunization and fetal anemia

  In this condition, a baby has blood antigens (proteins) that the pregnant person does not have. The pregnant person’s immune system sees the baby’s red blood cells (RBCs) as a possible danger, so it makes antibodies against these cells. The antibodies cross the placenta and attach to the baby’s RBCs and destroy them. This can lead to low levels of RBCs or low-quality RBCs in the baby (fetal anemia). This means their body gets less oxygen. Fetal anemia can range from mild to serious. The most serious complications are fetal hydrops and heart failure. We treat this condition before birth by giving your baby a transfusion of RBCs or giving you medicines that suppress your immune system (IVIG).

• Alloimmune thrombocytopenia

  In this condition, the baby has a type of platelet that the pregnant person does not have. The pregnant person’s immune system sees the baby’s platelets as a possible danger, so it makes antibodies against them. The antibodies cross the placenta, attach to the baby’s platelets and destroy them. This can lead to very low levels of platelets in a baby and to bleeding problems for them, including bleeding in their brain (hemorrhagic stroke). At Seattle Children’s Fetal Care and Treatment Center, we treat this condition before birth by giving medicines that suppress the pregnant person’s immune system (IVIG) or medicines that limit the antibodies that cross the placenta (prednisone). After birth, we boost the baby’s platelet level, if needed, with a transfusion.

• Amniotic band syndrome

  Thin strands of tissue can form inside the amniotic sac and tangle around your baby. The strands can trap or put pressure on parts of your baby’s body, making creases. These strands are called amniotic bands. Usually, the bands affect only the skin and the soft tissue just under the skin. Some bands are tighter and go deeper, causing serious problems with how a baby develops. They can even amputate a limb. At Seattle Children’s, we offer fetal surgery to release amniotic bands, and we provide care after birth for babies and children with amniotic band syndrome. Read more.

• Anorectal malformations

  Anorectal malformations are problems with the way a baby’s anus or rectum forms before birth. This can mean the digestive tract ends in a closed pouch inside the body. Or the rectum (the end of the large bowel before the anus) may connect to the skin or urinary tract. Seattle Children’s Reconstructive Medicine Program provides complete care for babies born with these conditions. Read more.

• Cardiac arrhythmias

  An arrhythmia is an abnormal heartbeat. This can mean the heart beats too quickly or too slowly or without a regular pattern. If an arrhythmia of your baby’s heart is found during pregnancy, we recommend a fetal echocardiogram to learn more. You may receive a home heart rate monitor if we need to check your baby’s heart rate more closely. We teach you how to use the monitor, and our fetal cardiologists are available 24/7 to help with any concerns. Sometimes we give medicine to pregnant patients to treat the baby’s rhythm condition. We also can place small pacemakers specially designed for newborns.

• Chorioangioma

  This is a benign tumor of the placenta. It is an abnormal growth of blood vessels, which may connect to your baby via the umbilical cord. Most of these tumors do not need any treatment before your baby is born. A large chorioangioma may need to be treated. It can restrict your baby’s growth before birth and cause fetal hydrops, heart failure and increased risk of early (preterm) birth or death for your fetus or newborn. Seattle Children’s Fetal Care and Treatment Center offers several options to stop the growth of a chorioangioma and to protect the health of your developing baby.

• Chromosomal conditions

  Chromosomes are the parts of cells that contain genetic information. When the number or structure of chromosomes is not normal, it can cause health problems. For example, in Down syndrome, extra genetic material causes developmental delays and birth defects that need medical care. Seattle Children’s specialists from many areas of healthcare are experienced with caring for babies, children and teens who have chromosomal conditions.

• Conditions that can affect monochorionic twins

  Twins that share 1 placenta are called monochorionic. Most of these twins develop normally and are born with no problems. But some develop problems that relate to sharing a placenta. We offer fetal intervention for the following conditions that can affect monochorionic twins:

  • Twin-to-twin transfusion syndrome (TTTS) — One twin gives blood and nutrients to the other twin. The donor twin is at risk of not having enough water (dehydration), not having enough red blood cells (anemia) and not having enough amniotic fluid (oligohydramnios). The other twin is at risk of getting too much blood and too much amniotic fluid (polyhydramnios) and getting congestive heart failure. For both twins, there’s a risk of miscarriage or being born too early (preterm birth). Read more.
  • Twin anemia polycythemia syndrome (TAPS) — One twin has too few red blood cells (anemia). The other has too many (polycythemia). This happens because blood is flowing through tiny blood vessels from 1 twin to the other. The donor twin is at risk of not getting enough oxygen and nutrients to develop properly. The other twin is at risk of their blood getting too thick and causing a blockage or straining their heart. TAPS is a form of TTTS.
  • Twin reversed arterial perfusion (TRAP) — The heart of 1 twin pumps blood for both twins. Blood flows the wrong way in the twin without a pumping heart, which keeps their head and brain from developing. The twin whose heart took over for both babies is at risk of heart failure. The other twin will have serious problems with how they form, like no heart (acardius fetal malformation) or no head (acephalic); this twin will never be able to survive.
  • Selective intrauterine growth restriction (SIUGR) — If the twins are not sharing the placenta evenly, 1 twin may not get enough blood and nutrients to grow well. This can mean 1 twin is smaller than the other; in some cases, much smaller. SIUGR can range from mild to severe. In more serious cases, rapid changes in blood flow and blood pressure between the twins can put both twins at risk. The smaller twin with less placenta can be at risk of dying. This puts the larger twin at risk too.
  • Discordance for anomalies — This term means there is a difference (discordance) in how your twins are forming, even though they are “identical” twins. In this case, 1 twin is forming normally, and the other twin has problems (anomalies) with how their organs are forming. The problems and the risks to each twin can range from mild to serious.
• Congenital diaphragmatic hernia

  A congenital diaphragmatic hernia (CDH) is a hole in the thin muscle (diaphragm) that separates the chest from the belly (abdomen). Organs that should be in the belly can go through the hole into your baby’s chest. This affects how your baby’s lungs grow. Many babies with CDH have high blood pressure in their lungs and breathing problems. We have treated many babies with this rare condition at Seattle Children’s. Our Congenital Diaphragmatic Hernia Program offers more specialized care than any other children’s hospital in the Pacific Northwest. Our multidisciplinary team has cared for hundreds of children with CDH, from prenatal diagnosis through early adulthood. Learn more about CDH.

• Congenital heart disease and fetal heart failure

  If the heart does not form normally during pregnancy, a baby will be born with a congenital heart defect. There are many types.

  Heart defects and problems with the heart muscle or heart rhythm can cause heart failure. Heart failure happens when the heart cannot pump enough blood to the body’s other organs. Sometimes heart failure is caused by blood vessel problems in other organs.

  The cardiologists in our Fetal Care and Treatment Center are able to make fast, accurate prenatal diagnoses. By combining our expertise with the latest technologies, we can detect congenital heart defects as early as 14 weeks’ gestation. Whether your child needs a simple repair, a complex procedure or a heart transplant, our heart surgery outcomes are among the best in the nation year after year.

• Craniofacial conditions

  Every year, our Craniofacial Center treats hundreds of children with conditions from cleft lip and palate to rare syndromes that affect how the skull and face form. Sometimes an ultrasound during pregnancy shows a baby might have a craniofacial condition. Some families are at higher risk of genetic syndromes that affect the head and face. Our Craniofacial Center’s prenatal counseling team can help. 

• Cysts or masses in the abdomen

  A cyst or mass in your baby’s belly (abdomen) may show up on a prenatal ultrasound. These are among the more common conditions we see. Using imaging, like ultrasound and fetal MRI (magnetic resonance imaging), and sometimes other testing, our team will diagnose the type of cyst or mass your baby has. We look at how it affects your baby and plan any care they may need before or after birth.

• Fetal anemia secondary to parvovirus

  Parvovirus B19 (fifth disease) is a common childhood infection that usually causes a mild rash (sometimes called “slapped cheek” rash), if anything. Adults can get it too. If you get parvovirus while pregnant, most likely you will have no illness or mild illness and your developing baby will be fine. There is a small chance parvovirus infection will cause problems with how your baby makes red blood cells (RBCs). This can lead to anemia and, in severe cases, fetal hydrops and heart failure. We treat fetal anemia by giving your baby a transfusion of RBCs before birth.

• Genetic conditions

  Changes to genes play a role in genetic conditions. Sometimes these changes are passed from parents to children (inherited). Sometimes a child has a new change that was not passed down (called de novo). Genetic conditions can cause birth defects, developmental delays and other health issues that need care. If doctors find that your baby has a birth defect, we will check whether it is caused by a genetic condition.

• Intestinal atresia

  Intestinal atresia happens when part of your baby’s bowel (intestine) does not form completely. Instead of being an open tube, it is closed off in 1 or more places. Sometimes parts are missing. This condition prevents food and poop (stool) from moving all the way through your baby’s body. Your baby will need surgery. Our surgeons are very experienced at repairing the bowel so your baby can thrive. In rare cases when babies do not have enough intestine, our Intestinal Rehabilitation Program provides long-term comprehensive care to offer the best possible outcome. Read more.

• Lung lesions

  As a baby’s lungs develop before birth, sometimes an area of abnormal lung tissue forms. Lung lesions may form inside the normal lung or next to it. These conditions are often called congenital pulmonary airway malformations (CPAMs). They range from small to large and can be solid or filled with fluid. Finding these problems during pregnancy can help you and your healthcare team plan for your baby’s care.

  Small masses may have no effects at all. Larger masses may affect the health of your developing baby. They may prevent your baby’s lungs from developing fully and may press on your baby’s heart and blood vessels. At Seattle Children’s, we treat CPAMs both before and after birth. We also provide follow-up care to protect your child’s lung health as they grow. Read more.

• Neck masses

  Sometimes an ultrasound during pregnancy shows the baby has a large lump (mass) in their neck. Most common are lymphatic malformations that involve the body’s system for moving fluid (lymph system). Experts from Seattle Children’s Otolaryngology Department and Craniofacial Center meet with you during pregnancy. We assess whether the mass is likely to affect your baby’s ability to breathe at birth. We make a delivery plan with your childbirth team to support and treat your newborn.

• Neurologic conditions

  Sometimes imaging studies during pregnancy show a baby has something that is not normal about their brain or spine. Fetal neurological conditions can include brain malformations, ventriculomegaly, congenital hydrocephalus, spina bifida and other neural tube defects, like myelomeningocele. Our neurodevelopmental pediatrician and pediatric neurologist review the available information and talk with you about the possible effects on your child. We have the most experienced neuroradiologist in the region. Our craniofacial and neurosurgery outcomes are among the best in the nation.

• Pleural effusion and chylothorax

  Pleural effusion is the buildup of extra fluid around the lungs. In a developing baby, this usually happens because lymph has leaked into the space between their lungs and their chest wall (chylothorax). Often, the leak happens because a lymph vessel in their chest (thoracic duct) did not form properly. Pleural effusion can keep your baby’s lungs from developing as they should, and it can press on your baby’s heart and blood vessels. It can also lead to fetal hydrops and heart failure. Before birth, we offer options to drain the extra fluid to relieve harmful pressure. After birth, our pediatric experts provide any care your child needs to repair their lymph vessels or treat other related health problems.

• Renal and urologic abnormalities

  Urologic conditions affect the system that makes, stores and drains pee (urine). Renal conditions affect the kidneys. We work with experts in Urology and Nephrology to care for babies with these problems.

  Lower urinary tract obstruction is 1 type of urologic concern during pregnancy. If your developing baby’s urinary tract is blocked, their bladder can become too full of urine, and the amniotic fluid around your baby can dry up. (During the second half of pregnancy, your baby’s urine makes up part of the amniotic fluid that cushions them in your womb.) This can cause further problems with their urinary tract and kidneys, how their lungs develop and how their face and limbs are shaped. We offer options for treating the blockage either before or after birth. We also plan and provide any other care your baby may need after they are born to treat problems linked to the blockage.

• Skeletal abnormalities

  Problems with the way a baby’s skeleton forms include clubfoot, dwarfism and missing bones. Seattle Children’s Orthopedics team cares for babies, children and teens with these conditions, and they offer prenatal consultations. Please contact Orthopedics directly about skeletal concerns before birth.

• Vascular anomalies

  Vascular anomalies are abnormal blood vessels or lymphatic vessels. They range from simple birthmarks to large, deep clusters of tangled vessels. Sometimes they are a sign of an underlying condition that affects many parts of the body. The Fetal Care and Treatment Center team can help diagnose vascular anomalies and find out how these affect your baby. Our Vascular Anomalies Program is one of the largest and most experienced programs in the United States. We offer a wide range of treatments. Read more.