Introduction And Diagnostics

Intrauterine fetal therapy redefines the fetus as an independent, treatable patient to interrupt the pathophysiological progression of life-threatening congenital anomalies before irreversible organ damage occurs.
Prerequisites include ultra-fast fetal MRI for precise anatomical assessment and expanded Non-Invasive Prenatal Testing (NIPT) via cell-free fetal DNA to detect single-gene disorders like Sickle Cell Disease.

Medical Fetal Therapy

Involves administering pharmacological agents to the mother (transplacental) or directly injecting them into the amniotic fluid or fetal umbilical vein.

Condition	Therapeutic Intervention
Fetal Supraventricular Tachycardia	Transplacental Digoxin, Flecainide, or Sotalol; direct umbilical Amiodarone if refractory.
Complete Heart Block	Maternal Dexamethasone or Betamethasone combined with IVIG to halt progression.
Congenital Adrenal Hyperplasia	Maternal Dexamethasone before 9th week to suppress adrenal androgens and prevent virilization of female fetuses.
Fetal Goiter	Intra-amniotic injections of L-thyroxine to shrink the goiter.

Intrauterine Blood Transfusion (IUT): Direct cordocentesis into the umbilical vein to transfuse packed red blood cells for severe fetal anemia induced by Rh isoimmunization or Parvovirus B19.
Vesicoamniotic Shunting: Bypasses Lower Urinary Tract Obstruction (LUTO) caused by Posterior Urethral Valves, draining fetal urine to restore amniotic fluid and preserve lung development.
Thoracoamniotic Shunting: Treats massive macrocystic Congenital Pulmonary Airway Malformations (CPAM) or large pleural effusions causing mediastinal shift and hydrops.

Twin-To-Twin Transfusion Syndrome (TTTS): Fetoscopic Laser Photocoagulation (FLP) selectively ablates anastomoses on the shared placenta. The 2025 standard Solomon Technique utilizes a continuous laser line to completely dichorionize the placenta, reducing Twin Anemia Polycythemia Sequence (TAPS) from 16% to <3%.
Congenital Diaphragmatic Hernia (CDH): Fetoscopic Endoluminal Tracheal Occlusion (FETO) utilizes a detachable balloon inserted into the fetal trachea. The trapped lung fluid generates internal pressure, driving alveolar growth and increasing survival from 15% to >40% per the TOTAL Trial.

Myelomeningocele (Spina Bifida): Open in utero repair between 19 and 25 weeks reduces postnatal ventriculoperitoneal shunt requirements and doubles independent walking rates at 30 months. The 2026 paradigm shifts toward Fetoscopic Myelomeningocele Repair, offering equivalent neurological preservation while entirely preserving maternal uterine integrity and preventing uterine dehiscence risks.
Ex Utero Intrapartum Treatment (EXIT): Provides a stable surgical window during a modified Cesarean to secure a compromised fetal airway while maintaining intact placental circulation.

In Utero Hematopoietic Stem Cell Transplantation (IUHCT): Maternal stem cells are injected intravascularly into pre-immune fetuses (<14 weeks) to treat Alpha-Thalassemia Major without triggering Graft-Versus-Host Disease.
Mesenchymal Stem Cells (MSCs): Intrauterine injection aims to produce functional type I collagen and reduce fractures in lethal Osteogenesis Imperfecta.
Fetal Gene Therapy: Intra-amniotic or intravascular Adeno-Associated Virus (AAV) vectors are utilized for Spinal Muscular Atrophy and lysosomal storage diseases before the onset of irreversible neurodegeneration.

The 2026 guidelines firmly establish the "Maternal-Fetal Dyad," asserting absolute maternal autonomy; pregnant women cannot be coerced into assuming the massive risks of open fetal surgery to benefit the fetus.
Interventions must be strictly confined to accredited multidisciplinary Fetal Therapy Centers maintaining high case-volumes to assure low maternal morbidity.