II. Definitions
- Fetal Tachycardia
- Fetal Heart Rate >160 bpm for >=10 minutes
III. Causes: Mild Fetal Tachycardia (FHR 160-180 bpm)
- Usually benign if normal FHR Variability or accelerations (spontaneous or stimulated)
- Maternal Causes
- Maternal Fever or infection
- Maternal Dehydration
- Maternal anxiety
- Maternal Ketosis
- Maternal Thyrotoxicosis
- Maternal Anemia
- Medications
- Anticholinergic Medications (e.g. Benadryl)
- Sympathomimetic medications (e.g. Terbutaline)
- Stimulants
- Fetal Causes
- Fetal Anemia
- Prolonged fetal movement
- Severely Preterm Fetus
- Cardiac anomalies
- Chronic Fetal Hypoxia
IV. Causes: Significant Fetal Tachycardia (FHR >180 bpm)
- Chorioamnionitis (especially if Maternal Fever)
- Fetal Arrhythmia or congenital defect (FHR >200 bpm)
V. References
- Bailey (2000) ALSO, E:1-13
- Gabbe (2002) Obstetrics, p. 395
- Arnold (2020) Am Fam Physician 102(3): 158-67 [PubMed]
- Rylander (2001) Clin Fam Pract 3(2):287-305 [PubMed]