II. Definitions
- Early Deceleration
- Transient decrease in Fetal Heart Rate (FHR)
- Shape of deceleration mirrors contraction
- FHR deceleration starts with contraction
- FHR nadir correlates with peak of contraction
- Onset of Early Deceleration to nadir >=30 seconds
- FHR returns to baseline at end of contraction
- Typically does not fall >60 bpm below baseline
III. Causes
- Usually benign
- Indicates head compression in Second Stage of Labor
IV. 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]