Fetal medicine (MFM) is a specialized branch managing maternal and fetal health in high-risk pregnancies. Specialists are obstetricians/gynecologists with advanced training, covering medical, surgical, and genetic complications.
When Fetal Medicine Is Recommended
Fetal medicine is recommended for high-risk pregnancies, where increased complication chances exist for mother, baby, or both. Referrals often stem from pre-existing maternal conditions like hypertension, diabetes, cardiac disease, seizure disorders, or thyroid disease. Managing these requires specialized oversight to minimize risks.
Pregnancy complications also lead to referral, such as preeclampsia, placental issues, or a history of preterm birth. Multiple fetuses (twins, triplets) also place a pregnancy in a higher-risk category, requiring closer monitoring by a fetal medicine specialist.
Fetal concerns are another frequent referral reason, involving potential birth defects, growth issues, or developmental problems detected during routine prenatal screenings. An ultrasound indicating a structural abnormality prompts further assessment and guidance from a fetal medicine specialist. Preconception consultations are also offered for those with pre-existing medical, obstetrical, or genetic conditions planning pregnancy.
Diagnostic Approaches in Fetal Medicine
Diagnosing fetal conditions begins with advanced imaging, primarily detailed ultrasound. Ultrasound uses high-frequency sound waves to create images, assessing gestational age, growth, placental structure, blood flow, and physical exam. This non-invasive method helps identify potential abnormalities as early as 12 to 13 weeks, with a major anatomy scan around 20 weeks.
Fetal Magnetic Resonance Imaging (MRI) provides detailed information about anatomical structures, particularly the fetal brain, which may not be fully visualized by ultrasound. This imaging technique uses a magnetic field rather than ionizing radiation, safe in the second and third trimesters. MRI supplements ultrasound findings, offering a comprehensive view of complex conditions.
Beyond imaging, non-invasive and invasive diagnostic tests play a role. Non-invasive prenatal testing (NIPT) involves a maternal blood test to analyze cell-free fetal DNA. NIPT is highly sensitive for detecting common chromosomal abnormalities like Down syndrome, Trisomy 13, and Trisomy 18, and predict fetal sex. While NIPT is a screening test indicating risk, it does not provide a definitive diagnosis.
For a conclusive diagnosis, invasive procedures like amniocentesis and chorionic villus sampling (CVS) are available. Amniocentesis (after 15 weeks) involves ultrasound-guided needle insertion into amniotic fluid; fetal cells are tested for chromosomal abnormalities, genetic disorders, or infections. CVS (10-13 weeks) removes a small placental tissue sample, also under ultrasound guidance, for similar genetic analysis. Both carry a small miscarriage risk and are considered when screening tests suggest higher risk.
Fetal Interventions and Management
Once a fetal condition is diagnosed, fetal medicine specialists offer a range of interventions and management strategies, often called fetal therapy. These treatments improve outcomes for the unborn baby. In-utero surgical procedures are one category, specialized and performed at dedicated centers, ranging from minimally invasive to open fetal surgeries.
Percutaneous fetal surgery involves guiding needles, catheters, or shunts into the fetus with ultrasound, without a large incision. Examples include placing shunts to drain fluid from obstructed areas (e.g., bladder, chest), or intrauterine fetal blood transfusions for severe anemia. Fetoscopic surgery, another minimally invasive approach, uses small incisions and endoscopic visualization to perform procedures inside the uterus, such as laser ablation for twin-to-twin transfusion syndrome.
Open fetal surgery is the most invasive approach, involving an incision into the mother’s abdomen and uterus to access and operate on the fetus. This surgery is performed for specific, life-threatening conditions like myelomeningocele (a severe form of spina bifida) or large sacrococcygeal teratomas. After repair, the uterus is closed, and the pregnancy continues with careful monitoring for preterm labor.
Medical management of fetal conditions also plays a role, often involving transplacental medications. This therapy can accelerate fetal lung maturation, reduce neural tube defects, or manage fetal cardiac arrhythmias. Prenatal counseling is an integral part of management, providing families with information about the diagnosed condition, treatment options, potential outcomes, and what to expect during and after delivery.
The Multidisciplinary Fetal Medicine Approach
Fetal medicine care is collaborative, involving a team of specialists providing comprehensive support for the pregnant individual and baby. Maternal-fetal medicine specialists (MFMs) coordinate the overall care plan, working closely with other medical professionals to address complex needs of high-risk pregnancies and fetal conditions.
The team includes genetic counselors, helping families understand genetic conditions, interpret test results, and explore reproductive options. Pediatric surgeons are involved when in-utero surgical interventions are considered or when postnatal surgery is anticipated. Neonatologists, specialists in newborn care, prepare for the baby’s birth and manage their care immediately after delivery, especially if the baby requires intensive care.
Additional specialists frequently contribute expertise, depending on the specific fetal condition. Including pediatric cardiologists for heart defects, pediatric neurosurgeons for brain or spinal conditions, and social workers for emotional and practical family support. This integrated, team-based approach ensures all aspects of care, from diagnosis and intervention to delivery planning and postnatal follow-up, are coordinated to achieve the best possible outcomes.