Many people with lymphatic malformations (LMs) and complex lymphatic anomalies (CLAs) wonder whether they will be able to have children someday. It's a common question—and for many individuals, the answer is yes. While every situation is different, many women and men with lymphatic conditions go on to build families and have healthy children.
Because lymphatic conditions vary widely in type and severity, pregnancy and family planning decisions should always be individualized and guided by experienced care teams.
Can LMs or CLAs be passed on to children?
Isolated LMs and many CLAs are caused by genetic changes that occur after conception and are not inherited from a parent. Because every diagnosis is unique, genetic counseling may be recommended if you have questions about family risk or inheritance.
Please see our informational charts for isolated LMs and CLAs.
Can people with LMs or CLAs have children?
Many people with LMs and CLAs can safely have children. Some individuals may need additional planning, specialized care, or discussions about timing depending on how their condition affects their health. However, some individuals may be advised to delay or avoid pregnancy depending on their medical situation.
Pregnancy may be discouraged or postponed when:
- The lymphatic condition affects the lungs, heart, chest, or abdomen
- There is a history of severe fluid buildup such as pleural effusions or ascites
- The condition is associated with higher pregnancy-related medical risks
- Pregnancy could significantly worsen symptoms or pose serious health concerns
- Certain systemic medications cannot be safely discontinued
Early counseling with an experienced care team can help clarify risks, timing, and available options.
what women with LMs and CLAs should know about pregnancy
Pregnancy causes normal changes in hormones, blood flow, and fluid balance. Some women with lymphatic conditions may notice:
- Increased swelling or fullness
- Temporary enlargement of affected areas
- Changes in pain or discomfort
- Fluid-related symptoms, especially in those with CLAs
For many, these changes are mild and improve after delivery. Some women may require closer monitoring during pregnancy, particularly if their condition involves the chest, lungs, heart, or abdomen.
what men with LMs and CLAs should know about fertility
Most men with LMs or CLAs do not experience fertility problems related to their condition. However, treatment history and the location of disease involvement may influence individual circumstances.
Men may benefit from counseling if they:
- Have a CLA
- Have pelvic, abdominal, or chest involvement
- Are receiving or have received systemic treatment
- Have fertility or medication-related concerns
sirolimus, fertility, and pregnancy
Expert consensus indicates that sirolimus does not appear to cause permanent infertility in women or men. Menstrual cycles and sperm production often recover after stopping treatment. Sirolimus is:
- Usually stopped before trying to conceive
- Not typically recommended during the first part of pregnancy
- Adjusted or stopped in coordination with your healthcare team
Some medications used to treat isolated LMs and CLAs — including sirolimus, alpelisib, trametinib, thalidomide, and other targeted therapies—may need to be stopped 3 to 6 months before trying to conceive. The timing varies depending on the specific treatment and your individual medical situation. Many experts recommend discussing pregnancy plans several months in advance so medication changes can be made safely.
Pre-pregnancy counseling is especially important for individuals considering or currently receiving these therapies. Do not stop or change medications on your own—always discuss plans with your medical team.
sirolimus and menstrual health
Some women taking sirolimus may experience changes in their menstrual cycle, including:
- Irregular periods
- Pain with menstruation (dysmenorrhea)
- Development of ovarian cysts
These effects are often reversible after stopping the medication.
pregnancy care and delivery
Most women with LMs or CLAs receive routine obstetric care. In some cases, the healthcare team may also include:
- An obstetrician
- A maternal-fetal medicine (MFM) specialist
- A lymphatic or vascular anomalies specialist
Many women with LMs or CLAs can have a vaginal delivery. Delivery planning should be individualized based on both obstetric factors and the location and extent of the lymphatic condition.
after delivery
After birth, hormone and fluid levels gradually return toward baseline. Some individuals experience:
- Temporary swelling that improves over weeks to months
- A return to pre-pregnancy symptom patterns
Your care team will discuss:
- When and how to restart medications
- Breastfeeding considerations
- Follow-up care for both parent and baby
Thinking about pregnancy or starting a family can bring up many questions. Your situation is unique, and you do not have to navigate these decisions alone. An experienced care team can help you understand your options, plan ahead, and make informed decisions that are right for you and your family.
helpful resources and references
The following resources may be helpful for patients and healthcare providers who are looking for more information about pregnancy, fertility, and lymphatic conditions.
- VASCERN-VASCA Consensus Statement: Sirolimus and Fertility
- Pregnancy & Family Planning in Vascular Anomalies – Patient Booklet by the European Reference Network on Rare Multisystemic Vascular Diseases (VASCERN)
- Pregnancy and PIK3CA-Related Overgrowth Spectrum: New Insights from Alpelisib Treatment
