When Is Intervention on a Baby in the Womb Necessary? How Are Fetal Interventions Performed?

Detecting a disease or developmental problem in a baby in the womb does not always mean that intervention is necessary. In many cases, close monitoring of the pregnancy is sufficient, while in some conditions a fetal intervention may be considered before birth in order to alter a process that threatens the baby’s life or adversely affects organ development.

The decision to perform a fetal intervention is not based solely on the name of the condition. The severity of the condition and its likelihood of progression, gestational age, the extent to which the baby’s organs are affected, the presence of other accompanying anomalies, and the potential benefits and risks of the procedure for both the mother and the baby are evaluated together.

Fetal intervention is the general term for procedures performed while the baby is still in the womb to prevent the progression of a disease, increase the baby’s chance of survival, or reduce the risk of permanent organ damage.

For this reason, “fetal intervention” and “fetal surgery” do not mean the same thing. A significant proportion of fetal interventions can be performed using a thin needle or catheter inserted through the mother’s abdomen under ultrasound guidance. In some cases, a thin camera system called a fetoscope is used, while more extensive fetal surgery may be required for selected conditions.

The method to be used is determined according to the baby’s condition and the intervention that needs to be performed.

The primary aim of fetal intervention is not to perform a procedure simply because an abnormality is seen on ultrasound. Intervention is generally considered when there is a risk that the condition may cause serious harm to the baby while the pregnancy continues and when this process can potentially be altered by fetal treatment.

For example, a severe obstruction in the baby’s urinary tract may lead to a reduction in amniotic fluid and impaired lung development. In twin-to-twin transfusion syndrome (TTTS), abnormal vascular connections in the placenta may affect the circulation of both babies. In severe fetal anemia, the baby’s heart may be placed under increased strain, and heart failure or hydrops may develop if the condition is left untreated.

In such situations, not only the presence of the condition but also the risk of waiting is compared with the risk associated with intervention.

No. Detecting an abnormality on ultrasound alone is not sufficient to make a decision for fetal intervention.

In the first stage, the diagnosis should be clarified as much as possible. Detailed ultrasonography is the primary assessment method. Depending on the baby’s condition, additional methods such as fetal echocardiography, fetal MRI, Doppler examinations, amniocentesis, or other genetic investigations may be used.

The important issue here is not only the answer to the question “What condition does the baby have?” The following questions also need to be answered:

• How severe is the condition?
• Is it progressing?
• Which of the baby’s organs are affected?
• Is there another accompanying anomaly?
• What is expected to happen during pregnancy if it is not treated?
• Is it possible to wait until after birth?
• Can an intervention in the womb change the outcome?

One of the most important aspects of fetal treatment is appropriate patient selection. Even in two babies with the same condition, the severity of the disease and the characteristics of the pregnancy may differ, so the treatment approach may not be the same.

When deciding on intervention, three main factors are evaluated together:

1. The natural course of the condition:
How is the condition expected to progress if no intervention is performed?

2. The potential benefit of fetal treatment:
Can the procedure meaningfully improve the baby’s survival, organ development, or condition after birth?

3. The risk of the procedure for the mother and baby:
What are the potential risks of the intervention, such as preterm birth, rupture of membranes, bleeding, infection, or pregnancy loss?

Therefore, the fundamental question in fetal intervention is not simply “Can this procedure be performed?” The more important question is “Is performing this procedure in this pregnancy more beneficial than waiting?”

Fetal interventions can be performed using different methods depending on the treatment required.

In some procedures, the targeted area of the baby or placenta is reached with a thin needle through the mother’s abdominal wall. The position of the needle is monitored by ultrasound throughout the procedure.

For example, in severe fetal anemia, an intrauterine blood transfusion can be performed using this method. The appropriate fetal blood vessel is accessed and the blood needed by the baby is administered.

Similar techniques may also be used in some situations to drain fluid, obtain samples, or administer medication to the baby.

In some conditions in which fluid accumulating in the baby’s body needs to be continuously drained, a small tube called a shunt may be used.

For example, in severe lower urinary tract obstruction (LUTO), a vesicoamniotic shunt may be placed to allow urine accumulated in the baby’s bladder to drain into the amniotic cavity.

Similarly, when an amount of fluid that may interfere with lung development accumulates in the baby’s chest cavity, a thoracoamniotic shunt may be used.

These procedures are generally performed under ultrasound guidance.

Fetoscopy is a minimally invasive method in which a very thin camera system is advanced into the uterus to allow direct visualization of the baby, umbilical cord, or placenta.

One of its best-known applications is the fetoscopic laser treatment of twin-to-twin transfusion syndrome (TTTS). In this procedure, the abnormal vascular connections between babies sharing a single placenta are visualized and closed using laser energy.

Fetoscopic methods may also be used in suitable patients for FETO in congenital diaphragmatic hernia, certain complicated twin pregnancies, and the treatment of specific fetal conditions.

In certain selected conditions, open fetal surgery may be performed, in which the uterus is surgically opened to reach the baby.

One of the best-known examples is the closure of the opening in the baby’s spine during pregnancy in selected cases of myelomeningocele (spina bifida) that meet appropriate criteria.

Because open fetal surgery is a more extensive operation for the mother than minimally invasive interventions, it is considered only for certain conditions and suitable patients.

The aim of fetal intervention varies depending on the condition.

In some procedures, the mechanism causing the condition is directly addressed. In others, the aim is to reduce harm to the baby during the period until birth or to support the development of vital organs.

For example, while a blood transfusion performed for fetal anemia corrects the baby’s anemia, one of the main aims of a shunt placed because of severe urinary tract obstruction is to help preserve the amniotic fluid and, consequently, lung development.

For this reason, the success of fetal treatment is not evaluated solely by asking “Has the condition completely disappeared?” The safe continuation of the pregnancy, protection of the baby’s organs, and improvement of the baby’s condition after birth may also be among the goals of treatment.

Yes. Fetal interventions are not completely risk-free procedures for either the mother or the baby.

The risks vary depending on the method used, gestational age, and the condition of the mother and baby. Depending on the procedure, complications such as rupture of membranes, preterm birth, bleeding, infection, placental complications, or pregnancy loss may occur.

The risks of open fetal surgery and a minimally invasive procedure performed under ultrasound guidance are also not the same.

For this reason, before a fetal intervention, it is important to provide the family with detailed information about the expected benefits of the procedure, possible risks, alternatives, and the expected course of the condition if no intervention is performed.

Performing a fetal intervention does not mean that the treatment process has ended.

After the procedure, the baby’s response to treatment, amniotic fluid, placenta, fetal circulation, and the overall course of the pregnancy are assessed at regular intervals. Depending on the treatment performed, serial ultrasound and Doppler examinations may be required.

While some treatments may be completed with a single procedure, in some situations the procedure may need to be repeated. For example, in fetal anemia, more than one intrauterine transfusion may be required depending on the baby’s condition.

The timing and mode of delivery, as well as any treatment the baby may require after birth, are also planned during pregnancy.

When a fetal intervention is recommended, it is important first of all that the family understands the diagnosis, the severity of the condition, and the purpose of the intervention.

Knowing the answers to the following questions may make the decision-making process easier for families:

• What is the main purpose of the intervention?
• How is the condition expected to progress if the procedure is not performed?
• What benefit can the intervention provide to the baby?
• What are the risks for the mother and the baby?
• Is there another treatment option or an option of monitoring only?
• How will the pregnancy be monitored after the procedure?
• Where and how should delivery be planned?
• Will the baby require additional treatment after birth?

The aim of fetal treatment is not simply to perform a procedure that is technically possible. The aim is to identify the right case in which the expected benefit for the mother and baby is greater than the risks and to perform the right intervention at the appropriate time.

No. Fetal interventions include different methods ranging from ultrasound-guided needle procedures and shunt applications to fetoscopic techniques and open fetal surgery.

The anesthesia method varies according to the type of procedure to be performed. Local anesthesia may be sufficient for some minimally invasive interventions, while different anesthesia methods may be required for more extensive procedures.

Yes. Depending on the type of condition and the baby’s response to treatment, some procedures may need to be repeated. In particular, treatments such as intrauterine blood transfusion may be performed more than once during pregnancy.

Depending on the type of fetal intervention, there may be risks such as preterm birth or premature rupture of the membranes. This risk varies according to the type of procedure, gestational age, and the condition of the mother and baby.

No. For many fetal conditions, the most appropriate approach is close monitoring and providing the necessary treatment after birth. Fetal interventions are considered only in selected situations in which intervention during pregnancy may change the baby’s course.

This content has been prepared for general informational purposes. The decision for fetal intervention should be made on an individual basis by evaluating the condition of the mother and baby, gestational age, and the characteristics of the condition together.