Fetal Monitoring
QUICK LOOK AT THE CHAPTER AHEAD
The concept of fetal monitoring is based on the fact that labor is a period of physiologic stress for the fetus. Therefore, frequent monitoring can measure fetal well-being by the response of the fetal heart rate to uterine contractions.
There are two types of electronic fetal monitoring: the external method and the internal method. The external fetal monitor is a noninvasive method and does not require that the membranes be ruptured or that cervical dilation has occurred. The internal fetal monitor is an invasive method and requires the membranes to be ruptured and the cervix to be dilated.
The concept of fetal monitoring is based on the fact that labor is a period of physiological stress for the fetus.The concept of fetal monitoring is based on the fact that labor is a period of physiological stress for the fetus. Therefore frequent monitoring can measure fetal well-being by the response of the fetal heart rate (FHR) to uterine contractions. Fetal oxygen supply must be maintained during labor to prevent fetal compromise and to promote newborn health after birth.
There are normal/reassuring FHR patterns:
A FHR in the normal range of 110-160 beats per minute is considered to be a baseline FHR provided there are no periodic changes and a moderate baseline variability (fluctuations in the FHR).
Accelerations with fetal movement (an increase in FHR above the baseline, with a return to baseline within 10 minutes).
There are abnormal/non-reassuring FHR patterns:
Tachycardia of 160 beats per minute or more.
Progressive increase or decrease in baseline rate
Progressive decrease in baseline variability
Absence of FHR variability
Severe bradycardia (less than 70 beats per minute)
Prolonged deceleration (greater than 60-90 seconds)
Late decelerations that are repetitive and uncorrectable (slowing of the FHR that begins after the onset of a contraction. The FHR returns to baseline after the contraction has ended.)
Severe variable decelerations (slowing of the FHR due to umbilical cord compression)
There are abnormal/nonreassuring FHR patterns.There are two types of electronic fetal monitoring:
External method: External transducers are placed on the maternal abdomen to assess FHR and uterine activity.
Internal method: A spiral electrode is applied to the fetal presenting part to assess the fetal electrocardiogram (ECG) and an intrauterine pressure catheter (IUPC) assesses uterine activity and pressure.
EXTERNAL FETAL MONITORING
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
