ch 18 fetal assessment during labor

The three-tiered system of FHR tracings include category I, II, and III. Category I is a normal tracing requiring no action. Category II FHR tracings are indeterminate and includes tracings that do not meet category I or III criteria. Category III tracings are abnormal and require immediate intervention.

A FHR of 110 to 160 beats per minute is considered normal and belongs in category I.

Prolonged decelerations Prolonged decelerations are caused by a disruption in the fetal oxygen supply. They usually begin as a reflex response to hypoxia. If the disruption continues, then the fetal cardiac tissue, itself, will become hypoxic, resulting in direct myocardial depression of the FHR.

A prolonged deceleration is a visually apparent decrease (may be either gradual or abrupt) in the FHR of at least 15 beats per minute below the baseline and lasting longer than 2 minutes but shorter than 10 minutes.

What is the most likely cause for variable fetal heart rate (FHR) decelerations? a. Altered fetal cerebral blood flow b. Umbilical cord compression c. Uteroplacental insufficiency d. Fetal hypoxemia

ANS: B Variable FHR decelerations can occur at any time during the uterine contracting phase and are caused by compression of the umbilical cord.

Which fetal heart rate (FHR) finding is the most concerning to the nurse who is providing care to a laboring client? a. Accelerations with fetal movement b. Early decelerations c. Average FHR of 126 beats per minute d. Late decelerations

ANS: D Late decelerations are caused by uteroplacental insufficiency and are associated with fetal hypoxemia. Late FHR decelerations are considered ominous if they are persistent and left uncorrected. Early decelerations in the FHR are associated with head compression as the fetus descends into the maternal pelvic outlet; they are not generally a concern during normal labor. An FHR finding of 126 beats per minute is normal and not a concern.

Procedure for intermittent auscultation of FHR pdf p. 1289

AWHONN recommends the following IA frequencies for low-risk women who are not receiving oxytocin: latent phase (<4 cm) at least hourly; latent phase (4 to 5 cm) every 15 to 30 minutes; active phase(≥6 cm) every 15 to 30 minutes; second stage passive fetal descent every 15 minutes; and second stage, active pushing every 5 to 15m

Category III FHR tracings include the following: • Absent baseline variability and any of the following: • Recurrent late decelerations • Recurrent variable decelerations • Bradycardia • Sinusoidal pattern

Abnormal FHR patterns are those associated with fetal hypoxemia, which is a deficiency of oxygen in the blood If uncorrected, hypoxemia can deteriorate to severe fetal hypoxia, an inadequate supply of oxygen at the cellular level that can cause metabolic acidosis. which can lead to acidemia.

absent or minimal variability is classified as either abnormal or indeterminate. possible causes: When the fetus is temporarily in a sleep state, minimal variability is present. * (*benign condition) A woman in labor with extreme prematurity may display a FHR pattern of minimal or absent variability.

Abnormal variability may also be related to fetal hypoxemia and metabolic acidemia. Congenital anomalies or a preexisting neurologic injury may also result in absent or minimal variability. central nervous system (CNS) depressant medications, narcotics, or general anesthesia.

A variable deceleration is likely caused by umbilical cord compression which may happen when... umbilical cord is around the baby's neck, arm, leg, or other body part or when a short cord, a knot in the cord, or a prolapsed cord is present.

Clinical Significance Variable decelerations occur in approximately 50% of all labors and usually are transient and correctable Nursing Interventions The usual priority is as follows: 1. Discontinue oxytocin if infusing. 2. Change maternal position (side to side, knee chest). 3. Administer oxygen at 10 L/min by nonrebreather face mask. 4. Notify physician or nurse-midwife. 5. Assist with vaginal or speculum examination to assess for cord prolapse. 6. Assist with amnioinfusion if ordered. 7. Assist with birth (vaginal-assisted or cesarean) if pattern cannot be corrected.

responsibilities of the perinatal nurses

Correctly interpreting fetal heartrate (FHR) pattern initiating appropriate nursing interventions documenting the outcomes

Amnioinfusion continued Risks of amnioinfusion are overdistention of the uterine cavity and increased uterine tone.

Fluid is administered through an IUPC by either gravity flow or an infusion pump. Usually a bolus of fluid is administered over 20 to 30 minutes; then the infusion is slowed to a maintenance rate. Likely no more than 1000 mL of fluid will need to be administered. Uterine resting tone should not exceed 40 mm Hg during the procedure. The amount of vaginal fluid return must be estimated and documented during mnioinfusion to prevent overdistention of the uterus.

As a tool, EFM has high sensitivity, meaning that the reassuring combined presence of moderate variability and accelerations nearly always mean a well-oxygenated fetus.

However, it has a low specificity (many false positives), meaning that suspicious patterns may or may not indicate actual distress

Early decelerations (and accelerations) do not generally need any nursing intervention.

Late decelerations suggest that the nurse should change the maternal position (lateral). Variable decelerations also require a maternal position change (side to side).

Which outcome might occur if the interventions for maternal hypotension are inadequate?

Low maternal blood pressure reduces placental blood flow during uterine contractions, resulting in fetal hypoxemia.

EFM Ultrasound transducer is placed over the area where fetal heart rate is best heard, usually below the umbilicus, and toco transducer is placed on the uterine fundus

Maternal obesity, occiput posterior position of the fetus, and anterior attachment of the placenta can cause weak or absent signals with ultrasound transducer. signals

Umbilical cord blood acid-base determination In assessing the immediate condition of the newborn after birth, a sample of cord blood is a useful adjunct to the Apgar score, especially if there has been an abnormal or confusing FHR tracing during labor or neonatal depression at birth. the procedure is performed by withdrawing blood from both the umbilical artery and the umbilical vein. Both samples are then tested for pH, carbon dioxide pressure (PCO 2), oxygen pressure (PO 2), and base deficit or base excess. Umbilical arterial values reflect fetal condition, whereas umbilical vein values indicate placental function

Normal findings preclude the presence of acidemia at or immediately before birth. If acidemia is present (e.g., pH <7.20), the type of acidemia is determined (respiratory, metabolic, or mixed) by analyzing the blood gas values

Prolonged decelerations lasting longer than 10 minutes are considered a baseline change that may require intervention

Nurses should immediately notify the physician or nurse-midwife and initiate appropriate treatment of abnormal patterns when they see this.

Prolonged decelerations Prolonged decelerations can be caused by prolonged cord compression, uteroplacental insufficiency, or perhaps sustained head compression.

Prolonged decelerations

Changes n FHR are categorized as periodic or episodic. These patterns include both accelerations and decelerations. Accelerations with fetal movement are an indication of fetal well-being.

The baseline FHR is measured over 10 minutes; a normal range is 110 to 160 beats per minute. Bradycardia is a FHR less than 110 beats per minute for 10 minutes or longer. Tachycardia is a FHR higher than 160 beats per minutes for 10 minutes or longer.

The two methods of fetal stimulation used most often in clinical practice are scalp stimulation (using digital pressure during a vaginal examination) and vibroacoustic stimulation (using an artificial larynx or fetal acoustic stimulation device on the maternal abdomen over the fetal head continuously for 1 to 5 seconds).

The desired result of these stimulation methods is an acceleration in the FHR of at least 15 beats/min for at least 15 seconds A FHR acceleration indicates the absence of metabolic acidemia. If the fetus does not respond to stimulation with an acceleration, fetal compromise is not necessarily indicated; however, further evaluation of fetal well-being is needed. Fetal stimulation should be performed at times when the FHR is at baseline. Neither fetal scalp nor vibroacoustic stimulation should be instituted if FHR decelerations or bradycardia are present

When FHR is auscultated, it should be described as a baseline number or range and as having a regular or irregular rhythm.

The presence of abrupt or gradual increases or decreases in FHR before, during, and immediately after contractions should also be noted

The five essential components of the FHR tracing that must be evaluated regularly are baseline rate, baseline variability, accelerations, decelerations, and changes or trends over time. Whenever one of these five essential components is assessed as abnormal, corrective measures must be taken immediately.

The purpose of these actions is to improve fetal oxygenation The term intrauterine resuscitation is sometimes used to refer to specific interventions initiated when an abnormal FHR pattern is noted.

The supine position can cause maternal hypotension, which impairs placental perfusion and fetal oxygenation.

The semi-Fowler position is the recommended side-lying position with a lateral tilt to the uterus.

Category III FHR tracings are prompt interventions include: providing supplemental oxygen instituting maternal position changes increasing IV fluid administration

These interventions are implemented to improve uterine and intervillous space blood flow and increase maternal oxygenation and cardiac output

The nurse providing care for a high-risk laboring woman is alert for late fetal heart rate (FHR) decelerations. Which clinical finding might be the cause for these late decelerations?

Uteroplacental insufficiency Late decelerations / 'Placenta'

Late decelerations are associated with uteroplacental insufficiency. Late FHR decelerations may be caused by maternal supine hypotension syndrome These decelerations are usually corrected when the woman turns onto her side to displace the weight of the gravid uterus from the vena cava

V C E H A O L P If the fetus does not respond to primary nursing interventions for late decelerations, then the nurse should continue with subsequent intrauterine resuscitation measures and notify the health care provider.

Variable decelerations are associated with umbilical cord compression.

V C E H A O L P Variable / Cord Compression

the most likely cause for early decelerations in the fetal heart rate (FHR) pattern Early decelerations are the fetus' response to fetal head compression; these are considered benign, and interventions are not necessary.

V C E H A O L P early decels / head compression

Amnioinfusion infusion of room-temperature isotonic fluid (usually normal saline or lactated Ringer solution) into the uterine cavity if the volume of amniotic fluid is low. Without the buffer of amniotic fluid, the umbilical cord can easily become compressed during contractions or fetal movement, diminishing the flow of blood between the placenta and fetus. The purpose of amnioinfusion is to relieve intermittent umbilical cord compression that results in variable decelerations and transient fetal hypoxemia by restoring the amniotic fluid volume to a normal or near-normal level.

Women with an abnormally small amount of amniotic fluid (oligohydramnios) or no amniotic fluid (anhydramnios) are candidates for this procedure. Conditions that can result in oligohydramnios or anhydramnios include uteroplacental insufficiency and prelabor rupture of membranes.

Basis for monitoring fetal status oxygen supply can decrease in a number of ways: -reduction of blood flow as a result of hypertension, hypotension >supine maternal position, hemorrhage, epidural anesthesia, or hypovolemia (caused by hemorrhage) reduction in 02 content in maternal blood as result of hemorrhage or anemia

alterations in fetal circulation occurring with compression of umbilical cord (transient, during UCs or prolonged resulting from cord prolapse) partial placental separation or complete abruption. or head compression causes increased ICP vagal nerve stimulation and decrease in FHR. reduction in blood flow to intervilous space in placenta secondary to deterioration of placental vasculature related to maternal disorders such as HTN or DM. Fetal well-being during labor can be measured by the response of the FHR to UCs

normal uterine activity during labor contraction frequency, duration, strength frequency generally ranges from 2 to 5 per 10 minutes during labor, with lower frequencies seen in 1st stage and higher frequencies seen in second stage. duration - remains fairly stable 45-80 seconds not generally exceeding 90 seconds. strength - range from peaking at 40-70mm Hg in 1st stage to over 80 in second stage.

contractions paplates as mild would likely peak at less than 50, moderate or strong would be higher. resting tone should be soft 10mmHg relaxation time 60 sec or more in 1st stage and 45 sec or more in second sage

Early deceleration in the FHR are associated with..

head compression as the fetus descends into the maternal pelvic outlet; they are not generally a concern during normal labor.

A major shortcoming of EFM is its

high rate of false-positive results.

to relieve FHR decelration the nurse can reposition the mother, increase IV fluids and provide oxygen.

if oxytocin is infusing then it should be discontinued. (The administration of Pitocin may place additional stress on the fetus.) If the FHR does not resolve, then the primary care provider should be immediately notified. if the FHR were to continue in non-reassuring pattern then a section would be warrented.

Amnioinfusion An amnioinfusion may be used to relieve pressure on an umbilical cord that has not prolapsed

introduction of a solution into the amniotic sac; an isotonic solution is most commonly used to relieve fetal distress

There's a good device now that uses bluetooth, one patch, pt can move around, get baby and mom ecg and UA .. good stuff This integrated monitoring system eliminates much of the problem caused by signal loss resulting from maternal or fetal movement or maternal obesity that often occurs with traditional external monitors. The monitor also more accurately measures the frequency, occurrence of peak, and duration of UCs than does the traditional toco transducer, although it does not provide actual intensity measurement in millimeters of mercury (mm Hg) as an IUPC does.

it eliminates the need of belts and frequent re-adjustment of the taco the device is only approved for use in monitoring singleton pregnancies at term

likely to cause accelerations of the FHR: Spontaneous fetal movement, vaginal examination, fetal scalp stimulation,

likely to cause accelerations of the FHR: fetal reaction to external sounds, uterine contractions, fundal pressure, abdominal palpation

Prolonged decelerations- Prolonged decelerations are late or variable decelerations that last for a prolonged period (longer than 2 minutes) and require intervention

may result in fetal death if there is no response to intrauterine resuscitation

IUPC (intrauterine pressure catheter)

measures contraction frequency, duration, strength(in mm mercury).

Category I FHR tracings include all of the following: • Baseline rate 110-160 beats/min (bpm) • Baseline FHR variability: moderate • Late or variable decelerations: absent • Early decelerations: either present or absent • Accelerations: either present or absent

moderate variability: amplitude range 6bpm to 25 bpm

Filling the mother's vascular system increases the amount of blood available to perfuse the placenta and may correct hypotension.

most fluids for laboring women are isotonic and do not provide extra glucose.

Umbilical cord compression results in...

variable FHR decelerations