What is perimembranous ventricular septal defect in a fetus, and what should be done about it?

Perimembranous ventricular septal defect refers generally to a defect in the perimembranous portion of the ventricular septum. In most cases, a fetal perimembranous ventricular septal defect may be associated with factors such as maternal psychological stress, genetic predisposition, inappropriate medication use during pregnancy, viral infections in early pregnancy, and electromagnetic radiation exposure. If this condition occurs, management options include regular color Doppler ultrasound examinations, amniocentesis, postnatal pharmacological treatment, interventional therapy, or open-heart surgery after birth. Specific details are analyzed below:

I. Causes

1. Psychological Stress
Strong psychological stress experienced by pregnant women during pregnancy—such as extreme pressure or significant emotional fluctuations—may negatively affect fetal development, including abnormal cardiac formation, potentially leading to the aforementioned condition.

2. Genetic Factors
If there is a family history of perimembranous ventricular septal defect or other congenital heart diseases among relatives, the fetus may have an increased risk of developing this condition.

3. Inappropriate Medication Use During Pregnancy
The use of certain medications during pregnancy may increase the risk of fetal perimembranous ventricular septal defect. Specific drugs, particularly some antiepileptic and antidepressant agents, have been associated with fetal cardiac structural abnormalities.

4. Viral Infections in Early Pregnancy
Maternal infection with certain viruses during the first trimester—such as rubella virus, cytomegalovirus, or Coxsackie virus—may increase the risk of fetal perimembranous ventricular septal defect. These viruses can cross the placenta and affect the developing fetus, leading to cardiac malformations.

5. Electromagnetic Radiation
Exposure to high-intensity electromagnetic radiation may adversely affect fetal cardiac development and increase the risk of perimembranous ventricular septal defect.

II. Management Approaches

1. Regular Color Doppler Ultrasound Examinations
If the fetus shows no other abnormalities and is developing normally, it is recommended to undergo regular color Doppler ultrasound examinations to monitor fetal development. In some cases, the defect may resolve spontaneously after birth, so excessive concern is usually unnecessary.

2. Amniocentesis
Although mild fetal perimembranous ventricular septal defects often do not require direct treatment, amniocentesis should be performed to check for chromosomal or genetic disorders in the fetus. If serious genetic abnormalities are detected, termination of pregnancy may be considered.

3. Postnatal Pharmacological Treatment
If the perimembranous ventricular septal defect persists after birth but is mild, presenting only with symptoms such as mild tachypnea, excessive sweating, and pallor, drug therapy under medical supervision—such as furosemide injection or atenolol injection—may be recommended to support normal growth and development.

4. Interventional Therapy
Interventional therapy typically refers to transcatheter closure of ventricular septal defects. This approach is minimally invasive and allows for rapid recovery. It is generally suitable for children aged ≥3 years with hemodynamically significant, isolated ventricular septal defects.

5. Open-Heart Surgery After Birth
Open-heart surgery is a surgical technique used to treat fetal perimembranous ventricular septal defect. The procedure involves direct intracardiac repair of the ventricular septal defect to restore normal cardiac structure and function.

Pregnant women are advised to attend regular prenatal check-ups, avoid self-medication, maintain a light diet, and seek prompt medical attention if any discomfort arises.