OB ATI: Chapter 6 - Assessment of Fetal Well Being

Ultrasound

- a procedure lasting approximately 20 min that consists of high-frequency sound waves used to visualize internal organs and tissues by producing a real-time, three-dimensional image of the developing fetus and maternal structures (FHR, pelvic anatomy). - An ultrasound allows for early diagnosis of complications, permits earlier interventions, and thereby decreases neonatal and maternal morbidity and mortality. - There are three types of ultrasound: external abdominal, transvaginal, and Doppler.

The diagnostic procedures to be reviewed include

- ultrasound (abdominal, transvaginal, Doppler) - biophysical profile - nonstress test - contraction stress test (nipple, oxytocin [Pitocin] - amniocentesis

CST: Interpretation of findings - A negative CST (normal finding) is indicated if within a

10-min period, with three uterine contractions, there are no late decelerations of the FHR.

BPP assesses fetal well-being by measuring the following five variables with a score of

2 for each normal finding, and 0 for each abnormal finding for each variable.

A nurse is caring for a client who is pregnant and is to undergo a contraction stress test (CST). Which of the following findings are indications for this procedure? (Select all that apply.) A. Decreased fetal movement B. Intrauterine growth restriction (IUGR) C. Postmaturity D. Advanced maternal age E. Amniotic fluid emboli

A, B, C, D

A nurse is caring for a client who is in preterm labor and is scheduled to undergo an amniocentesis to assess fetal lung maturity. Which of the following is a test for fetal lung maturity? A. Alpha-fetoprotein (AFP) B. Lecithin/sphingomyelin (L/S) ratio C. Kleihauer-Betke test D. Indirect Coombs' test

B

A nurse is caring for a client and reviewing the findings of the client's biophysical profile (BPP). Which of the following variables are included in this test? (Select all that apply.) A. Fetal weight B. Fetal breathing movement C. Fetal tone D. Reactive FHR E. Amniotic fluid volume

B, C, D, E

A nurse is teaching a client who is pregnant about the amniocentesis procedure. Which of the following statements by the client requires clarification? A. "I will report cramping or signs of infection to the physician." B. "I should drink lots of fluids during the 24 hours following the procedure." C. "I need to have a full bladder at the time of the procedure." D. "The test is done to detect genetic abnormalities."

C

A nurse is caring for a client who is pregnant and undergoing a nonstress test. The client asks why the nurse is using an acoustic vibration device. Which of the following is an appropriate response by the nurse? A. "It is used to stimulate uterine contractions." B. "It will decrease the incidence of uterine contractions." C. "It lulls the fetus to sleep." D. "It awakens a sleeping fetus."

D

NST: Miscellaneous

Disadvantages of a NST include a high rate of false nonreactive results with the fetal movement response blunted by sleep cycles of the fetus, fetal immaturity, maternal medications, and chronic smoking.

PUBS: Interpretation of findings

Evaluates for isoimmune fetal hemolytic anemia and assesses the need for a fetal blood transfusion. ● Nursing actions ◯ Administer medication as prescribed. ◯ Offer support.

Nursing actions for a transvaginal ultrasound: Client education

Fetal and maternal structures may be pointed out to the client as the ultrasound procedure is performed.

Amniocentesis: Postprocedure

Nursing actions ■ Monitor the client's vital signs, FHR, and uterine contractions throughout and 30 min following the procedure. ■ Have the client rest for 30 min. ■ Administer RhO(D) immune globulin (RhOGAM) to the client if she is Rh-negative (standard practice after an amniocentesis for all women who are Rh-negative to protect against Rh isoimmunization). Client education ■ Advise the client to report to her provider if she experiences fever, chills, leakage of fluid, or bleeding from the insertion site, decreased fetal movement, vaginal bleeding, or uterine contractions after the procedure. ■ Encourage the client to drink plenty of liquids and rest for the 24 hr postprocedure.

Amniocentesis: Intraprocedure

Nursing actions ■ Obtain client's baseline vital signs and FHR, and document prior to the procedure. ■ Assist client into a supine position, and place a wedge under her right hip to displace the uterus off the vena cava, and place a drape over the client exposing only her abdomen. ■ Prepare client for an ultrasound to locate the placenta. ■ Cleanse client's abdomen with an antiseptic solution prior to the administration of a local anesthetic by the provider. Client education ■ Advise the client that she will feel slight pressure as the needle is inserted. She should continue breathing because holding her breath will lower the diaphragm against the uterus and shift the intrauterine contents.

CST: Complications

Potential for preterm labor

Quad marker screening

a blood test that ascertains information about the likelihood of fetal birth defects. - It does not diagnose the actual defect. Includes testing for: ■ Human chorionic gonadotropin (hCG) - a hormone produced by the placenta ■ Alpha-fetoprotein (AFP) - a protein produced by the fetus ■ Estriol - a protein produced by the fetus and placenta ■ Inhibin-A - a protein produced by the ovaries and placenta

Doppler ultrasound blood flow analysis

a noninvasive external ultrasound method to study the maternal-fetal blood flow by measuring the velocity at which RBCs travel in the uterine and fetal vessels using a handheld ultrasound device that reflects sound waves from a moving target. - It is especially useful in fetal intrauterine growth restriction (IUGR) and poor placental perfusion, and as an adjunct in pregnancies at risk because of hypertension, diabetes mellitus, multiple fetuses, or preterm labor.

External abdominal ultrasound

a safe, noninvasive, painless procedure whereby an ultrasound transducer is moved over a client's abdomen to obtain an image. An abdominal ultrasound is more useful after the first trimester when the gravid uterus is larger.

Nipple stimulated CST consists of

a woman lightly brushing her palm across her nipple for 2 min, which causes the pituitary gland to release endogenous oxytocin, and then stopping the nipple stimulation when a contraction begins. The same process is repeated after a 5-min rest period.

CVS is a first-trimester alternative to

amniocentesis with one of its advantages being an earlier diagnosis of any abnormalities. - CVS can be performed at 10 to 12 weeks of gestation, and rapid results with chromosome studies are available in 24 to 48 hr following aspiration.

Internal transvaginal ultrasound

an invasive procedure in which a probe is inserted vaginally to allow for a more accurate evaluation. An advantage of this procedure is that it does not require a full bladder. ■ It is especially useful in clients who are obese and those in the first trimester to detect an ectopic pregnancy, identify abnormalities, and to establish gestational age. ■ A transvaginal ultrasound also may be used in the third trimester in conjunction with abdominal scanning to evaluate for preterm labor.

Chorionic villus sampling (CVS)

assessment of a portion of the developing placenta (chorionic villi), which is aspirated through a thin sterile catheter or syringe inserted through the abdominal wall or intravaginally through the cervix under ultrasound guidance and analyzed.

CST: Hyperstimulation of the uterus (uterine contraction longer than 90 seconds or more frequent than every 2 min) should be

avoided by stimulating the nipple intermittently with rest periods in between and avoiding bimanual stimulation of both nipples unless stimulation of one nipple is unsuccessful.

Contractions started with oxytocin may be

difficult to stop and can lead to preterm labor.

Interpretation of findings: Nonreactive NST indicates that the fetal heart rate

does not accelerate adequately with fetal movement. - It does not meet the above criteria after 40 min. - If this is so, a further assessment, such as a contraction stress test (CST) or biophysical profile (BPP), is indicated.

Nonstress test (NST)

most widely used technique for antepartum evaluation of fetal well-being - performed during the third trimester - it is a noninvasive procedure that monitors response of the FHR to fetal movement. How does it work? - A Doppler transducer, used to monitor the FHR, and a tocotransducer, used to monitor uterine contractions, are attached externally to a client's abdomen to obtain tracing strips. The client pushes a button attached to the monitor whenever she feels a fetal movement, which is then noted on the tracing. This allows a nurse to assess the FHR in relationship to the fetal movement.

Maternal serum alpha-fetoprotein (MSAFP) is a screening tool used to detect

neural tube defects. - Clients who have abnormal findings should be referred for a quad marker screening, genetic counseling, ultrasound, and an amniocentesis.

Oxytocin (Pitocin) administration CST is used if

nipple stimulation fails and consists of the IV administration of oxytocin to induce uterine contractions.

Interpretation of findings: The NST is interpreted as reactive if the FHR is a

normal baseline rate with moderate variability, accelerates to 15 beats/min for at least 15 seconds and occurs two or more times during a 20-min period.

CST: Interpretation of findings - A positive CST (abnormal finding) is indicated with

persistent and consistent late decelerations on more than half of the contractions. - This is suggestive of uteroplacental insufficiency. - Variable deceleration may indicate cord compression, and early decelerations may indicate fetal head compression. - Based on these findings, the provider may determine to induce labor or perform a cesarean birth.

Amniocentesis

the aspiration of amniotic fluid for analysis by insertion of a needle transabdominally into a client's uterus and amniotic sac under direct ultrasound guidance locating the placenta and determining the position of the fetus. - It may be performed after 14 weeks of gestation.

CST: Analysis of the FHR response to contractions (which decrease placental blood flow) determines how

the fetus will tolerate the stress of labor. - A pattern of at least three contractions within a 10-min time period with duration of 40 to 60 seconds each must be obtained to use for assessment data.

Percutaneous umbilical blood sampling (PUBS)

the most common method used for fetal blood sampling and transfusion. - This procedure obtains fetal blood from the umbilical cord by passing a fine-gauge, fiber-optic scope (fetoscope) into the amniotic sac using the amniocentesis technique. - The needle is advanced into the umbilical cord under ultrasound guidance, and blood is aspirated from the umbilical vein.

Biophysical profile (BPP)

uses a real-time ultrasound to visualize physical and physiological characteristics of the fetus and observe for fetal biophysical responses to stimuli.

MSAFP: Indications

■ All pregnant clients, preferably between 16-18 weeks of gestation ● Interpretation of findings ◯ High levels may indicate a neural tube defect or open abdominal defect. ◯ Lower levels may indicate Down syndrome. ◯ Preparation of a client ■ Discuss testing with the client. ■ Draw blood sample. ■ Offer support and education as needed.

Amniocentesis: Complications

■ Amniotic fluid emboli ■ Maternal or fetal hemorrhage ■ Fetomaternal hemorrhage with Rh isoimmunization ■ Maternal or fetal infection ■ Inadvertent fetal damage or anomalies involving limbs ■ Fetal death ■ Inadvertent maternal intestinal or bladder damage ■ Miscarriage or preterm labor ■ Premature rupture of membranes ■ Leakage of amniotic fluid Nursing actions ■ Monitor the client's vital signs, temperature, respiratory status, FHR, uterine contractions, and vaginal discharge for amniotic fluid or bleeding. ■ Administer medication as prescribed. ■ Offer support and reassurance.

Unltrasound: Ongoing care

■ Apply an ultrasonic/transducer gel to the client's abdomen before the transducer is moved over the skin to obtain a better fetal image, ensuring that the gel is at room temperature or warmer. ■ Allow the client to empty her bladder at the termination of the procedure. ● Nursing actions for a transvaginal ultrasound

NST: Indications for the use of an NST during pregnancy - Potential diagnoses for

■ Assessing for an intact fetal CNS during the third trimester. ■ Ruling out the risk for fetal death in clients who have diabetes mellitus. Used twice a week or until after 28 weeks of gestation.

Nursing actions for a transvaginal ultrasound: Preparation of client

■ Assist the client into a lithotomy position. The vaginal probe is covered with a protective device, lubricated with a water-soluble gel, and the client or examiner inserts the probe.

Indications for the use of an ultrasound during pregnancy: Potential diagnoses for:

■ Confirming pregnancy ■ Confirming gestational age by biparietal diameter (side-to-side) measurement ■ Identifying multifetal pregnancy ■ Site of fetal implantation (uterine or ectopic) ■ Assessing fetal growth and development ■ Assessing maternal structures ■ Confirming fetal viability or death ■ Ruling out or verifying fetal abnormalities ■ Locating the site of placental attachment ■ Determining amniotic fluid volume ■ Fetal movement observation (fetal heartbeat, breathing, and activity) ■ Placental grading (evaluating placental maturation) ■ Adjunct for other procedures (e.g., amniocentesis, biophysical profile)

CST: Client presentation

■ Decreased fetal movement ■ Intrauterine growth restriction ■ Postmaturity ■ Gestational diabetes mellitus ■ Gestational hypertension

NST: Client Presentation

■ Decreased fetal movement ■ Intrauterine growth restriction ■ Postmaturity ■ Gestational diabetes mellitus ■ Gestational hypertension ■ Maternal chronic hypertension ■ History of previous fetal demise ■ Advanced maternal age ■ Sickle cell disease ■ Isoimmunization

Nursing actions for a transvaginal ultrasound: Ongoing care

■ During the procedure, the position of the probe or tilt of the table may be changed to facilitate the complete view of the pelvis. ■ Inform the client that pressure may be felt as the probe is moved.

Ultrasound: Preparation of client

■ Explain the procedure to the client and that it presents no known risk to her or her fetus. ■ Advise the client to drink 1 to 2 quarts of fluid prior to the ultrasound to fill the bladder, lift and stabilize the uterus, displace the bowel, and act as an echolucent to better reflect sound waves to obtain a better image of the fetus. ■ Assist the client into a supine position with a wedge placed under her right hip to displace the uterus (prevents supine hypotension).

Amniocentesis: Preprocedure

■ Explain the procedure to the client, and obtain informed consent. ◯ Client education ■ Instruct the client to empty her bladder prior to the procedure to reduce its size and reduce the risk of inadvertent puncture.

PUBS: Potential diagnoses

■ Fetal blood type, RBC, and chromosomal disorders ■ Karyotyping of malformed fetuses ■ Fetal infection ■ Altered acid-base balance of fetuses with IUGR

CST: Indications for the use of a contraction stress test during pregnancy - Potential diagnoses

■ High-risk pregnancies (gestational diabetes mellitus, postterm pregnancy) ■ Nonreactive stress test

CST: Interventions

■ Initiate IV oxytocin administration if nipple stimulation fails to elicit a sufficient uterine contraction pattern. If hyperstimulation of the uterus and/or preterm labor occurs, do the following: ☐ Monitor for contractions lasting longer than 90 seconds and/or occurring more frequently than every 2 min. ☐ Provide administration of tocolytics as prescribed. ☐ Maintain bed rest during the procedure. ☐ Observe the client for 30 min afterward to see that contractions have ceased and preterm labor does not begin.

CST: Ongoing care

■ Initiate nipple stimulation if there are no contractions. Instruct the client to roll a nipple between her thumb and fingers or brush her palm across her nipple. The client should stop when a uterine contraction begins. ■ Monitor and provide adequate rest periods for the client to avoid hyperstimulation of the uterus.

CVS: Client education

■ Instruct the client to drink plenty of fluid to fill the bladder prior to the procedure to assist in positioning the uterus for catheter insertion. ■ Provide ongoing education and support.

NST: Ongoing care

■ Instruct the client to press the button on the handheld event marker each time she feels the fetus move. ■ If there are no fetal movements (fetus sleeping), vibroacoustic stimulation (sound source, usually laryngeal stimulator) may be activated for 3 seconds on the maternal abdomen over the fetal head to awaken a sleeping fetus.

CST: Preparation of client

■ Obtain a baseline of the FHR, fetal movement, and contractions for 10 to 20 min, and document. ■ Explain the procedure to the client, and obtain informed consent. ■ Complete an assessment without artificial stimulation if contractions are occurring spontaneously.

Indications: Client presentation

■ Preferred at 16-18 weeks gestation ■ Women at risk for giving birth to a neonate who has a genetic chromosomal abnormality

Indications for the use of an amniocentesis during pregnancy: Potential diagnoses

■ Previous birth with a chromosomal anomaly ■ A parent who is a carrier of a chromosomal anomaly ■ A family history of neural tube defects ■ Prenatal diagnosis of a genetic disorder or congenital anomaly of the fetus ■ Alpha fetoprotein level for fetal abnormalities ■ Lung maturity assessment ■ Fetal hemolytic disease ■ Meconium in the amniotic fluid

NST: Preparation of client

■ Seat the client in a reclining chair, or place in a semi-Fowler's or left-lateral position. ■ Apply conduction gel to the client's abdomen. ■ Apply two belts to the client's abdomen, and attach the FHR and uterine contraction monitors.

CVS: Complications

■ Spontaneous abortion (higher risk with CVS than with amniocentesis) ■ Risk for fetal limb loss ■ Miscarriage ■ Chorioamnionitis and rupture of membranes

Ultrasound: Client presentation

■ Vaginal bleeding evaluation ■ Questionable fundal height measurement in relationship to gestational weeks ■ Reports of decreased fetal movements ■ Preterm labor ■ Questionable rupture of membranes ● Nursing actions for an ultrasound

CVS: Indications for the use of CVS during pregnancy - Potential diagnoses

■ Women at risk for giving birth to a neonate who has a genetic chromosomal abnormality (cannot determine spina bifida or anencephaly)

PUBS: Complications

◯ Cord laceration ◯ Preterm labor ◯ Amnionitis ◯ Hematoma ◯ Fetomaternal hemorrhage

Quad marker screening: Interpretation of findings

◯ Low levels of AFP may indicate a risk for Down syndrome. ◯ High levels of AFP may indicate a risk for neural tube defects. ◯ Higher levels than the expected reference range of hCG and Inhibin-A indicates a risk for Down syndrome. ◯ Lower levels than the expected reference range of estriol may indicate a risk for Down syndrome.

● Potential diagnoses

◯ Nonreactive stress test ◯ Suspected oligohydramnios or polyhydramnios ◯ Suspected fetal hypoxemia and/or hypoxia

● Client presentation

◯ Premature rupture of membranes ◯ Maternal infection ◯ Decreased fetal movement ◯ Intrauterine growth restriction

● Nursing Actions

◯ Prepare the client following the same nursing management principles as those used for an ultrasound.

● Interpretation of findings

◯ Total score of 8 to 10 is normal; low risk of chronic fetal asphyxia ◯ 4 to 6 is abnormal; suspect chronic fetal asphyxia ◯ < 4 is abnormal; strongly suspect chronic fetal asphyxia