Congenital Lung Malformations (CLM)

The Stanford Medicine Children’s Health Fetal and Pregnancy Health Program has extensive expertise in taking care of children with congenital lung malformations. We are proud to care for a very high number of children with congenital lung malformations on the West Coast. We provide comprehensive evaluation, management, and long-term follow-up of children with all types of CLMs.

What are CLMs?

Congenital lung malformations (CLMs) occur when a baby’s lung tissue develops abnormally in utero. CLMs are rare but treatable, with excellent outcomes. CLMs occur in approximately 1 in 2,500 babies. There are different types of CLMs, with the most common being congenital pulmonary airway malformation (CPAM) and bronchopulmonary sequestration (BPS), and sometimes the defect can be a mix of the two. There are also rarer types of congenital lung formations, including bronchogenic cysts and congenital lobar emphysema. The cause of CLMs is unknown; our team conducts innovative research to help understand CLMs better.

What is CPAM?

Congenital pulmonary airway malformation (CPAM) is a type of CLM where cysts or a group of cysts form within the lung. It can sometimes compress your developing baby’s lungs or displace their heart, trachea, or blood vessels. Our team will watch you closely during pregnancy to monitor both you and your baby’s health.

What is BPS?

Bronchopulmonary sequestration (BPS) is a type of CLM where the lung tissue does not develop normally and forms a mass inside or outside the lung. The mass often connects to the aorta for its blood supply. Just like CPAMs, if a BPS grows large, it can push on nearby structures and blood vessels. It is not uncommon for a baby to have a “hybrid lesion,” meaning the malformation is a combination of BPS and CPAM, or a different type of CLM.

Are there signs during pregnancy that my baby has a CLM?

Most fetuses with a CLM do not show signs of the malformation. If the mass is large or rapidly changing, your baby might develop fetal hydrops (extra fluid around the heart, in the lungs, or in other parts of their body). 

How do you diagnose CLMs?

We use fetal ultrasound during pregnancy to detect congenital lung malformations. Ultrasounds enable us to see a mass or abnormal tissue in the lungs. If we suspect a CLM, we use MRI to investigate further, and fetal echocardiography to check your baby’s heart. We also repeat ultrasounds throughout pregnancy and use a congenital pulmonary airway malformation-volume ratio (CVR) to measure the size of the mass over time.

How do you treat my baby’s CLM?

We have extensive experience caring for mothers and fetuses with congenital lung malformations, and we are skilled at caring for babies after birth with simple to highly complex CLMs. The typical treatment for babies with CLMs is surgery after birth. Most babies do not have symptoms when they are born and are able to go home after a few days in the hospital. We then see you and your baby in clinic after a couple of months to get more imaging and discuss surgery at that time.

Do you ever treat my baby while I am still pregnant?

It is rare for a baby to require care while still in utero. If the malformation is large or causing hydrops, we sometimes treat it before birth by giving the mom steroids. Very rarely, fetal surgery (such as a thoraco-amniotic shunt to drain a cyst) is needed. For severe CLMs that are threatening your child’s health, we may also perform ex utero intrapartum treatment (EXIT), which is a procedure to safely deliver the baby and/or emergency surgery right after birth.

What can I expect if my baby needs surgery?

We typically perform surgery for babies with CLM between 3 and 6 months of age. Our highly skilled pediatric general surgeons provide a minimally invasive surgery (or keyhole surgery) to remove the diseased lung using small incisions and a camera. This almost always ensures minimal pain and a short hospital stay. Most babies go home the day after surgery.

What are the long-term outcomes for my baby with a CLM?

Most babies with a congenital lung malformation who receive treatment have excellent long-term outcomes. By the time your baby becomes a toddler, their remaining lung compensates and provides normal lung function. Your child will be able to engage in all activities without restriction, including sports. 

What can I expect during pregnancy?

During pregnancy, we continually check you and your baby with diagnostic tests, helping us to catch concerns, such as heart displacement, early. We tailor a care plan specifically for you and provide prenatal counseling, delivery planning, and postnatal intervention planning to achieve the best possible outcomes. If your developing baby’s lung mass is small and uncomplicated, you may be able to deliver at your local hospital while working with us on your baby’s surgery plan. If your fetus has a severe congenital lung malformation, we may recommend that you take prenatal steroids to slow the growth of the lung mass.

What can I expect after birth?

Most new mothers whose fetus has a CLM can expect a normal delivery and discharge, and they will be able to take their baby home as usual after birth. Before going home, we perform a chest x-ray on your baby to ensure that they do not have any concerning signs or symptoms. Occasionally, a baby with a large lung mass may need help breathing, and even surgery, right after birth. In this case, we create a surgery plan well ahead of delivery to ensure exceptional, seamless care for you and your baby. All babies go home with a detailed follow-up plan of care, which includes a CT scan at 2 to 3 months of age and follow-up with the pediatric surgery team.

Why should I choose Stanford Medicine Children’s Health for CLM care?

Because we are a high-volume center, we are expertly skilled at diagnosing and treating your child’s CLM, whether it is simple, complex, or extremely rare. When you come to us, we bring together our multidisciplinary care team designed for you and your child’s needs, including a pediatric surgeon, neonatologist, pulmonologist, and pediatric radiologist to ensure that you receive the highest quality of care available.

Do you research CLMs, and what are you learning?

Yes, our doctors are pleased to be a part of the North American Fetal Therapy Network (NAFTNet), which brings together the top CLM specialists from across the United States, Canada, Mexico, and South America to share knowledge and advance research and training. We are also part of the multi-institutional Congenital Lung Malformation Working Group, through which our doctors actively participate in congenital lung malformation research, keeping Stanford Children’s at the very leading edge of knowledge and innovations.

Our Congenital Lung Malformation care team also conducts our own research on CLMs, including on outcomes of pregnancies with fetal lung masses, using MRIs for preoperative decision-making, and genetic causes.