Maternal-Child Nursing McKinney Ch 15: Prenatal Diagnostic Tests

1. A pregnant woman's biophysical profile score is 8. She asks the nurse to explain the results. The nurse's best response is

a. "The test results are within normal limits."

b. "Immediate delivery by cesarean birth is needed."

c. "Further tests are needed to determine the meaning of this score."

d. "We will inform you of your options within the next week."

ANS: A "The test results are within normal limits."

The normal biophysical score ranges from 8 to 10 points if the amniotic fluid volume is adequate. A normal score allows conservative treatment of high-risk patients. Delivery can be delayed if fetal well-being is indicated. An immediate delivery is not needed. The results of the biophysical profile are usually available immediately after the procedure is performed.

2. Which analysis of maternal serum may predict chromosomal abnormalities in the fetus?

a. Multiple-marker screening

b. Lecithin/sphingomyelin (L/S) ratio

c. Biophysical profile

d. Type and crossmatch of maternal and fetal serum

ANS: A Multiple-marker screening

Maternal serum can be analyzed for abnormal levels of alpha-fetoprotein, human chorionic gonadotropin, and estriol. This multiple-marker screening may predict chromosomal defects in the fetus. The L/S ratio is used to determine fetal lung maturity. A biophysical profile is used for evaluating fetal status during the antepartum period. Five variables are used, but none is concerned with chromosomal problems. The blood type and crossmatch will not predict chromosomal defects in the fetus.

3. The nurse providing care for the pregnant woman understands that a factor indicating the need for fetal diagnostic procedures is

a. maternal diabetes.

b. maternal age older than 30 years.

c. previous infant more than 3000 g at birth.

d. weight gain of 25 pounds.

ANS: A maternal diabetes.

Diabetes is a risk factor in pregnancy because of possible impairment of placental perfusion. Other indications for testing include a maternal age greater than 35 years, having had another infant weighing greater than 4000 g at birth, or excessive weight gain. A weight gain of 25 to 35 pounds is recommended for the woman who begins pregnancy at a normal weight.

4. When is the best time to determine gestational age based on biparietal diameter through ultrasound?

a. First trimester only

b. Second trimester only

c. Any time

d. Second half of pregnancy

ANS: D Second half of pregnancy

The biparietal diameter is used to determine gestational age during the second half of pregnancy.

5. The primary reason for evaluating alpha-fetoprotein (AFP) levels in maternal serum is to determine if the fetus has

a. hemophilia.

b. a neural tube defect.

c. sickle cell anemia.

d. a normal lecithin/sphingomyelin (L/S) ratio.

ANS: B a neural tube defect.

An open neural tube allows a high level of AFP to seep into the amniotic fluid and enter the maternal serum. Hemophilia is a genetic defect and is best detected with chromosomal studies such as chorionic villus sampling or amniocentesis. Sickle cell is a genetic defect and is best detected with chromosomal studies such as chorionic villus sampling or amniocentesis. L/S ratios are determined with an amniocentesis, which is usually done in the third trimester.

6. While working with the pregnant woman in her first trimester, the nurse is aware that chorionic villus sampling (CVS) can be performed during pregnancy as early as _____ weeks.

a. 4

b. 8

c. 10

d. 12

ANS: C 10

CVS is usually performed between 10 and 13 weeks of gestation to diagnose fetal chromosomal, metabolic, or DNA abnormalities.

7. The nurse's role in diagnostic testing is to provide

a. advice to the couple.

b. assistance with decision making.

c. information about the tests.

d. reassurance about fetal safety.

ANS: C information about the tests.

The nurse should provide the couple with all necessary information about a procedure so that the couple can make an informed decision. The nurse's role is to inform, not to advise the couple. Decision making should always lie with the couple involved. Ensuring fetal safety is not possible with all of the diagnostic testing. To offer this is to give false reassurance to the parents.

8. The nurse teaches a pregnant woman that which diagnostic test evaluates the effect of fetal movement on fetal heart activity?

a. Contraction stress test (CST)

b. Sonography

c. Biophysical profile

d. Nonstress test (NST)

ANS: D Nonstress test (NST)

An NST evaluates the ability of the fetal heart to accelerate either spontaneously or in association with fetal movement. CST evaluates the fetal reaction to contractions. Sonographic examinations visualize the fetus and are done for various other reasons. The biophysical profile evaluates fetal status using many variables.

9. Which nursing intervention is necessary before a second trimester transabdominal ultrasound?

a. Place the woman NPO for 12 hours.

b. Instruct the woman to drink 1 to 2 quarts of water.

c. Administer a soapsuds enema.

d. Perform an abdominal prep.

ANS: B Instruct the woman to drink 1 to 2 quarts of water.

During the second trimester, a full bladder may be needed to displace the intestines and elevate the uterus for better visibility. If indicated, the woman should be instructed to drink several glasses of clear fluid an hour before the time of the examination and to delay urination until the examination is completed. Since she needs to fill her bladder, being NPO is not appropriate. Enemas and abdominal preps are not necessary for this procedure.

10. The major advantage of chorionic villus sampling (CVS) over amniocentesis is that it

a. is not an invasive procedure.

b. does not require hospitalization.

c. has less risk of spontaneous abortion.

d. is performed earlier in pregnancy.

ANS: D is performed earlier in pregnancy.

CVS is performed between 10 and 13 weeks of gestation, providing earlier results than amniocentesis, which is normally done during the second and third trimesters, although it can be done as early as 11 weeks if needed. The woman does not need hospitalization for this invasive procedure, and the risk of spontaneous abortion is about the same for both procedures.

11. What is the purpose of amniocentesis for the patient hospitalized at 34 weeks with pregnancy-induced hypertension?

a. Identification of abnormal fetal cells

b. Detection of metabolic disorders

c. Determination of fetal lung maturity

d. Identification of sex of the fetus

ANS: C Determination of fetal lung maturity

During the third trimester, amniocentesis is most often performed to determine fetal lung maturity. In pregnancy-induced hypertension, preterm delivery may be necessary because of changes in placental perfusion. It is not done to identify abnormal fetal cells, detect metabolic disorders, or identify the sex of the fetus.

12. An NST in which two or more fetal heart rate (FHR) accelerations of 15 beats per minute (bpm) or more occur with fetal movement in a 20-minute period is termed

a. nonreactive.

b. positive.

c. negative.

d. reactive.

ANS: D Reactive

The NST is reactive (normal) when two or more FHR accelerations of at least 15 bpm (each with a duration of at least 15 seconds) occur in a 20-minute period. A nonreactive result means that the heart rate did not accelerate during fetal movement. Positive and negative are not results given with this test.

13. The purpose of initiating contractions in a CST is to

a. determine the degree of fetal activity.

b. apply a stressful stimulus to the fetus.

c. identifying fetal acceleration patterns.

d. increase placental blood flow.

ANS: B apply a stressful stimulus to the fetus.

The CST involves recording the response of the FHR to stress induced by uterine contractions. The NST and biophysical profiles look at fetal movements. The NST looks at fetal heart accelerations with fetal movements. The CST records the fetal response to stress. It does not increase placental blood flow.

14. A pregnant woman states "This test isn't my idea, but my husband insists." Which response by the nurse is most appropriate?

a. "Don't worry. Everything will be fine."

b. "Why don't you want to have this test?"

c. "You're concerned about having this test?"

d. "It's your decision."

ANS: C "You're concerned about having this test?"

The nurse should clarify the statement and assist the patient in exploring her feelings about the test. Stating that everything will be fine is giving false reassurance and belittles the woman's concerns. "Why" questions usually put people on the defensive and are not therapeutic. Of course having the test is the woman's decision, but this closed statement does not encourage the woman to express her feelings.

15. A nurse is preparing a woman for a nonstress test (NST). What nursing action is most appropriate?

a. Position the woman on her left side.

b. Seat the woman comfortably in a recliner.

c. Have the woman to drink 1 liter of water prior to the test.

d. Place conduction gel on the obese woman's abdomen.

ANS: B Seat the woman comfortably in a recliner.

To correctly position the pregnant patient for an NST, the woman usually sits in a reclining chair. Alternatively she can be in a semi-Fowler position with a lateral tilt. This will optimize uterine perfusion and prevent supine hypotension. The woman does not need to drink water. Conduction gel is used in all NST tests.

16. Which statement regarding various biochemical assessments used during pregnancy is correct?

a. Chorionic villus sampling (CVS) is becoming more popular because it provides

early diagnosis.

b. Screening for maternal serum alpha-fetoprotein (MSAFP) levels is recommended

between 10 and 12 weeks of gestation in order to give parents time to consider

options.

c. Percutaneous umbilical blood sampling (PUBS) is one of the multiple marker

screen tests for Down syndrome.

d. MSAFP is a screening tool only; it identifies candidates for more definitive

procedures.

ANS: D MSAFP is a screening tool only; it identifies candidates for more definitive procedures

MSAFP is a screening tool, not a diagnostic tool. Further diagnostic testing is indicated after an abnormal MSAFP. CVS does provide a rapid result, but it is declining in popularity because of advances in noninvasive screening techniques. MSAFP screening is recommended for all pregnant women. Screening is recommended between 15 and 20 weeks of gestation. Abnormal findings give parents time to have additional tests done.

17. A woman is scheduled for an ultrasound and is asking the nurse questions about this test. Which statement by the nurse regarding ultrasonography during pregnancy is most accurate?

a. Ultrasonography uses infrared technology to create an image.

b. Ultrasonography is only utilized as an adjunct to more invasive tests.

c. Ultrasonography is not harmful to the fetus.

d. Ultrasonography is not a component of biophysical profile testing.

ANS: C Ultrasonography is not harmful to the fetus.

Most women look forward to the results of this test, which causes no harm to the fetus. Ultrasonography uses sound waves to create an image. As an adjunct to more invasive tests, ultrasonography can provide visual guidance for increased safety. It can be done as a standalone test. Ultrasonography is a component of biophysical profile testing.

18. A nurse is teaching a woman how to do "kick counts." What information about this assessment is most appropriate?

a. Notify your provider if the baby's movement patterns change.

b. Count the number of fetal movements over 2 hours.

c. Call the OB triage area if there are fewer than 10 movements/hour.

d. Have your partner verify your count at the same time you perform it.

ANS: A Notify your provider if the baby's movement patterns change.

Since there is no consensus on how the mother should be taught to perform this assessment, it is more important that she become familiar with her baby's movements and patterns and notify the provider about any change from normal.

1. A patient is at 6 weeks' gestation and is having a transvaginal ultrasound. While preparing the patient for this procedure, she expresses concerns over the necessity for this test. The nurse explains that this diagnostic test may be necessary to determine which of the following? (Select all that apply.)

a. Multifetal gestation

b. Bicornuate uterus

c. Presence and location of pregnancy (intrauterine or elsewhere)

d. Amniotic fluid volume

e. Presence of ovarian cysts

ANS: A, B, C, E

A transvaginal ultrasound done in the first trimester can detect multifetal gestations, bicornuate uterus, presence and location of pregnancy, and presence of ovarian cysts. Amniotic fluid volume is assessed during the second and third trimesters.

2. The nurse teaches a student that indications for percutaneous umbilical cord sampling (PUBS) include which of the following? (Select all that apply.)

a. Rh disease

b. Fetal well-being

c. Infection

d. Lung maturity

e. Karyotyping

ANS: A, C, E

Rh disease, infection, and, infrequently, for karyotyping are all indications for PUBS. NST or BPP are used to determination fetal well-being. An amniocentesis is done in order to determine lung maturity.

1. A pregnant woman has the following assessments determined from a biophysical profile: reactive nonstress test, 3 fetal breathing movements within 30 minutes, 1 trunk movement in 30 minutes, opened and closed hand twice in 30 minutes, largest amniotic pocket of 1 cm. Calculate this woman's score.

This woman's score is _____.

ANS: 8

The scoring is as follows for each criteria: 2-2-1-2-1 = 8.