From the Guidelines
Fetal tachycardia, defined as a heart rate exceeding 160 beats per minute, is most commonly caused by maternal fever, maternal anxiety, maternal hyperthyroidism, and intrauterine infections, as well as fetal hypoxia, anemia, or cardiac arrhythmias such as supraventricular tachycardia or atrial flutter, as noted in the study by 1. The causes of fetal tachycardia can be categorized into several key areas, including:
- Maternal factors, such as fever, anxiety, and hyperthyroidism
- Fetal factors, including hypoxia, anemia, and cardiac arrhythmias
- Intrauterine infections
- Maternal use of stimulants or medications like beta-agonists
- Placental insufficiency or fetal distress Some specific causes of fetal tachycardia include:
- Supraventricular tachycardia
- Atrial flutter
- Fetal hypoxia
- Anemia
- Intrauterine infections
- Maternal fever
- Maternal anxiety
- Maternal hyperthyroidism
- Maternal use of stimulants or medications like beta-agonists Management of fetal tachycardia depends on identifying and treating the underlying cause, which may involve addressing maternal fever with antipyretics, treating maternal infections with appropriate antibiotics, or managing maternal thyroid disease, as recommended by 1. In cases of fetal arrhythmias, maternal administration of antiarrhythmic medications like digoxin, flecainide, or sotalol may be necessary, as noted in the study by 1. Persistent unexplained fetal tachycardia warrants close monitoring and may require delivery if associated with signs of fetal compromise, particularly after 34 weeks gestation, as suggested by 1. It is essential to consider the potential causes of fetal tachycardia and to manage the condition accordingly to minimize morbidity, mortality, and improve quality of life for both the mother and the fetus, as emphasized by 1 and 1.
From the Research
Causes of Fetal Tachycardia
Fetal tachycardia is a condition where the fetal heart rate exceeds 160 beats per minute. The causes of fetal tachycardia can be varied and include:
- Maternal fever or hyperthermia 2, 3
- Fetal distress 4, 3
- Supraventricular tachycardia (SVT) 4
- Premature atrial contractions (PACs) 5
- Atrioventricular (AV) reentry tachycardia 5
- Atrial flutter 5
- Ventricular tachycardia 5
- Maternal intrapartum fever or chorioamnionitis 2
Fetal Tachycardia and Perinatal Morbidity
Fetal tachycardia has been associated with increased perinatal morbidity, including:
- Low arterial cord pH 2
- Base deficit ≥12 2
- Respiratory distress syndrome (RDS) 3
- Asphyxia 3
- Meconium aspiration 3
Diagnosis and Management
The diagnosis of fetal tachycardia is crucial for proper management. The use of cardiotocography can be helpful in detecting fetal tachycardia 4. The management of fetal tachycardia depends on the underlying cause and may include: