Learning that your baby may have a lymphatic malformation (LM) or complex lymphatic anomaly (CLA) can feel overwhelming. Many parents have questions about what the diagnosis means, what happens next, and what to expect during pregnancy and after birth.
It is important to remember that isolated LMs and most CLAs are developmental conditions. They are not caused by anything a parent did or did not do during pregnancy.
Some lymphatic conditions are identified during pregnancy, while others are diagnosed shortly after delivery. Every pregnancy is different, and outcomes vary widely depending on the size, location, and underlying cause of the condition. An experienced care team can help guide you through each step of the journey.
how are LMs and CLAs diagnosed during pregnancy
Most LMs grow proportionally with the fetus. In some cases, they may decrease in size or (rarely) resolve depending on the underlying cause.
routine ultrasound
Some lymphatic malformations can be identified as early as 9 weeks of pregnancy, while others are detected later in the first or second trimester. They may appear as fluid-filled cysts on ultrasound.
fetal MRI
Fetal MRI provides more detailed imaging to evaluate the size, location, and potential impact on nearby structures such as the airway, lungs, or heart.
genetic evaluation
In some cases, additional testing may be recommended, including:
- Amniocentesis
- Chorionic villus sampling (CVS)
Certain chromosomal or genetic conditions may be associated with lymphatic malformations, including:
- Trisomy 21 (Down syndrome)
- Turner syndrome
- Noonan syndrome
fetal echocardiography
A fetal echocardiogram may be performed to assess heart structure and function.
monitoring during pregnancy
When a lymphatic malformation or fluid complication is identified, ongoing monitoring is typically recommended.
This may include:
- Serial ultrasounds to monitor growth and help the care team plan for delivery and newborn care
- Fetal MRI in selected cases
- Fetal echocardiography
- Genetic consultation when indicated
- Referral to a maternal-fetal medicine specialist or fetal care center
Many pregnancies are managed with careful observation alone.
treatment during pregnancy
Most pregnancies do not require fetal intervention. In certain high-risk situations — particularly when fluid accumulation is severe or causing strain on the lungs or heart — fetal intervention is typically performed at specialized fetal care centers and may include:
- Ultrasound-Guided Drainage: Temporary removal of fluid from the fetal chest to relieve pressure.
- Thoracoamniotic Shunt Placement: Placement of a small tube that allows continuous drainage of chest fluid into the amniotic sac.
maternal medication therapy
In rare and carefully selected cases, medications such as mTOR inhibitors (sirolimus) have been used under specialist supervision. These approaches are individualized and managed by experienced fetal therapy teams.
Not all cases require intervention. Decisions are highly individualized based on:
- Severity
- Gestational age
- Underlying diagnosis
- Overall fetal stability
delivery planning
In many cases, delivery proceeds much like any other pregnancy. However, some babies may benefit from being born at a specialized center where a multidisciplinary team is immediately available. This team may include:
- maternal-fetal medicine specialists
- neonatologists
- pediatric surgeons
- anesthesiologists
In rare cases where airway compromise is expected, an EXIT (Ex-Utero Intrapartum Treatment) procedure may be performed. This allows the baby’s airway to be secured while still supported by the placenta.
after birth
Some babies require specialized care after birth, while others need only observation and routine follow-up. After delivery, newborns may require:
- Respiratory support
- Imaging (ultrasound or MRI)
- Chest tube drainage if pleural effusion is present
- Nutritional management for chylothorax
- Medication therapy
- Ongoing monitoring
Some infants require care in a neonatal intensive care unit (NICU), while others may only need observation.
Treatment depends on the underlying diagnosis and the baby’s overall health.
emotional support during pregnancy
Receiving a prenatal diagnosis can bring uncertainty and fear. It is important to remember:
- lymphatic malformations are developmental conditions.
- they are not caused by anything a parent did.
- outcomes vary widely.
You do not have to navigate a prenatal diagnosis alone. Connecting with experienced specialists, other families, and trusted resources can help you better understand the road ahead and make informed decisions for your child. While uncertainty can be difficult, many families find that having the right information, support, and care team helps them move forward with greater confidence and hope for the future.
