- Periodic auscultation - per minute basis.
- FHR - baseline without contraction should be 120-160 b/min; Baseline variability is dependent on fetal sleep/wake states, medications, hypoxia. Marked acceleration (more than 180b/min) may be related to prematurity, maternal fever, hypoxia, fetal infection, and drugs.
- External monitoring
- External Mode :
- 1.Tocotransducer - pressure-sensing device applied to maternal abdomen to monitor frequency and duration of contraction.
- 2. Ultrasound Transducer - continuous monitor of FHR, which can be interpreted in relation to contraction.
- 3. Phonotransducer and abdominal electrodes - fetal electrocardiogram.
- Internal Mode
- 1. Spiral electrode - applied to fetal presenting part; provides continuous measurement of FHR, baseline variability and periodic changes.
- 2. Intrauterine catheter - pressure transducedr inserted beyond presenting part; measures frequency, duration, and intensity of contractions.
4. Fetal scalp sampling - a small sample of fetal blood is taken from a punctured wound made into the fetal scalp to test for the presence of fetal acidosis. - Laboratory analysis of fetal pH is done; Normal value ranges from 7.25 to 7.35; A reported value of 7.20 or below means fetal acidosis.
