Which Conditions Can Be Treated in the Womb?

Detecting a disease or structural abnormality in a baby during pregnancy does not always mean that treatment must wait until after birth. Today, advances in fetal medicine make it possible to treat or intervene in certain conditions while the baby is still in the womb. These approaches, known as fetal therapy, encompass a range of methods, from medication and fetal blood transfusions to shunt procedures, fetoscopic interventions, and, in selected cases, fetal surgery.

However, not every condition detected in the womb is suitable for fetal therapy. Treatment decisions are made on an individual basis, taking into account the type and severity of the condition, gestational age, the baby’s condition, the potential benefits of treatment, and the possible risks to both the mother and the baby.

Fetal therapy is a general term for treatments performed during pregnancy to protect the health of the baby in the womb, prevent the progression of a disease, or reduce serious complications that may occur after birth.

Fetal therapy does not necessarily mean surgery. In some conditions, medications given to the mother reach the baby through the placenta, while in others, direct intervention on the baby or the umbilical cord may be performed under ultrasound guidance. In more complex cases, fetoscopic or surgical techniques may be used.

Fetal therapies can therefore generally be categorized as medical treatments, ultrasound-guided interventions, fetoscopic procedures, and fetal surgery.

The number of conditions that can be treated with fetal therapy continues to increase with advances in medicine. Today, some of the main conditions for which intervention may be performed in the womb under specific circumstances include:

Lower urinary tract obstruction (LUTO) is a condition in which an obstruction prevents urine from passing normally from the baby’s bladder. In male fetuses, one of the important causes is a congenital condition known as posterior urethral valves (PUV).

Severe obstruction of urinary flow can cause the baby’s bladder to become excessively enlarged, damage the kidneys, and reduce the amount of amniotic fluid. A severe reduction in amniotic fluid can, in particular, adversely affect lung development.

In selected cases, a vesicoamniotic shunt may be placed to allow urine from the bladder to drain into the amniotic cavity. In some centers, fetoscopic procedures aimed at relieving the obstruction may also be considered in suitable patients.

However, not every case of LUTO or PUV requires intervention in the womb. The condition of the kidneys, the amount of amniotic fluid, the severity of the obstruction, and gestational age are important factors in treatment decisions.

In some identical twin pregnancies in which the babies share a single placenta, blood flow between the twins may become imbalanced because of vascular connections within the placenta. This condition is known as Twin-to-Twin Transfusion Syndrome (TTTS).

When one baby receives less blood while excessive blood flows to the other, serious consequences may develop for both babies.

In appropriate cases, fetoscopic laser therapy can be used to close the abnormal vascular connections in the placenta. The aim is to stop the imbalanced blood flow between the two babies.

Similarly, fetal interventions may be performed in selected cases of certain complicated twin pregnancies, such as TAPS (Twin Anemia-Polycythemia Sequence) and TRAP sequence.

Severe anemia in a baby while still in the womb may occur due to blood group incompatibilities, certain infections, or other causes.

When severe fetal anemia is detected, an intrauterine blood transfusion may be performed. During this ultrasound-guided procedure, a blood vessel in the umbilical cord is generally accessed and compatible blood is transfused to the baby.

Intrauterine transfusion is one of the longest-established methods of fetal therapy and can be life-saving in certain circumstances.

A significant accumulation of fluid around the baby’s lungs is known as fetal pleural effusion or hydrothorax. A large amount of fluid can interfere with lung development and place pressure on the heart.

In appropriate cases, a thoracoamniotic shunt may be placed to allow the fluid in the chest cavity to drain into the amniotic cavity.

The aim is not simply to drain the fluid, but also to reduce pressure on the lungs and help them continue to develop.

Congenital diaphragmatic hernia (CDH) is a serious congenital abnormality in which organs from the abdomen move into the chest cavity through an opening in the diaphragm. The organs that enter the chest cavity can adversely affect the development of the baby’s lungs.

In severe and selected cases of CDH, a fetoscopic procedure known as FETO (Fetoscopic Endoluminal Tracheal Occlusion) may be performed. During this procedure, a small balloon is temporarily placed in the baby’s trachea with the aim of promoting lung development.

FETO is not performed in every case of diaphragmatic hernia. The severity of the condition, the degree of lung development, and other clinical characteristics are evaluated in detail.

Spina bifida is a congenital abnormality that develops during the formation of the baby’s spine and spinal cord. One of its severe forms is myelomeningocele.

In selected cases that meet appropriate criteria, fetal surgery may be performed to close the opening in the spine while the baby is still in the womb.

Prenatal repair does not completely eliminate the condition. The aim is to reduce further damage to the exposed neural tissue during pregnancy and to improve outcomes after birth in some babies.

Certain lesions that develop in the baby’s lungs, such as CPAM (Congenital Pulmonary Airway Malformation) or bronchopulmonary sequestration, may enlarge during pregnancy and place pressure on the heart and lungs.

A significant proportion of these cases require only close monitoring. However, fetal intervention may be considered depending on factors such as the size of the lesion, its effect on the baby’s circulation, or the development of hydrops.

Similarly, in certain fetal tumors, such as sacrococcygeal teratoma, options for intervention in the womb may be considered depending on the characteristics of the condition.

No. Not every abnormality detected in the womb has a fetal treatment option, and the availability of fetal therapy does not mean that an intervention should be performed in every patient.

Some abnormalities are simply monitored throughout pregnancy, with the necessary treatment performed after birth. In others, intervention in the womb may alter the natural course of the condition or improve the baby’s condition after birth.

For this reason, one of the most important aspects of fetal therapy is appropriate patient selection.

When considering an intervention in the womb, the diagnosis alone is not the only factor taken into account. The baby’s condition is comprehensively assessed using detailed ultrasound and, when necessary, fetal MRI, genetic testing, and other diagnostic methods.

The following questions are particularly important in the decision-making process:

• Will the condition progress during pregnancy if left untreated?
• Does it threaten the baby’s life or organ development?
• Can treatment in the womb alter the natural course of the condition?
• What are the risks of the procedure for the mother and the baby?
• Is the pregnancy at an appropriate gestational age for intervention?
• Is there another accompanying structural or genetic abnormality?

Based on these assessments, a decision is made as to whether monitoring, fetal therapy, or treatment after birth is the most appropriate approach.

The risks of fetal interventions vary depending on the method used. The risks associated with ultrasound-guided interventions are not the same as those associated with open fetal surgery.

Depending on the procedure, complications such as preterm birth, rupture of membranes, bleeding, infection, or pregnancy loss may occur. Therefore, the potential benefits of fetal therapy must be considered together with the risks it may pose to both the mother and the baby.

The aim is not simply to perform a procedure because it is technically possible, but to identify cases in which the expected benefit for the mother and baby outweighs the risks of the intervention.

Detecting a problem in the baby during an ultrasound examination does not necessarily mean that fetal therapy will be required. The first step is to determine exactly what the finding represents and how serious it is.

During a perinatology assessment, the characteristics of the abnormality are evaluated with detailed ultrasonography. If necessary, fetal MRI, genetic testing, or other advanced examinations may be planned. The family is then informed about the expected course of the condition, treatments that may be available during pregnancy, monitoring options, and the expected process after birth.

The fundamental approach in fetal therapy is not “to intervene whenever intervention is possible,” but rather to intervene in the right patient, at the right time, and using the appropriate method.

Yes. Open or fetoscopic fetal surgery can be performed for certain conditions. However, a significant proportion of fetal therapies do not require open surgery; ultrasound-guided needles, shunts, blood transfusions, or fetoscopic techniques may be used.

There is no single gestational age that applies to all fetal therapies. The appropriate timing depends on the condition, its severity, the baby’s development, and the type of procedure to be performed.

Not always. While some treatments aim to eliminate the cause of the condition, others are intended to reduce damage to the baby’s organs, allow the pregnancy to continue, or improve outcomes after birth.

Detailed ultrasound is generally the primary assessment method; however, depending on the case, fetal MRI, fetal echocardiography, genetic testing, or other investigations may be required.

Fetal interventions require advanced imaging, appropriate technical infrastructure, and a multidisciplinary team experienced in this field. The procedures available and patient selection criteria may vary between centers.

This content has been prepared for general informational purposes. Diagnosis and treatment decisions should be made by a physician after evaluating the individual clinical characteristics of both the mother and the baby.