2. Diagnostic tests to evaluate fetal growth and well-being
   • Daily fetal movement count (DFMC)
     1. Assesses fetal activity.
     2. Noninvasive test done by pregnant woman.
     3. Three movements per hour: normal activity.
     4. Two movements or less per hour may indicate fetal jeopardy or sudden change in movement pattern.
     5. Assess for fetal sleep patterns.
   • Nonstress test (NST)
     1. Correlates fetal movement with FHR. Requires electronic monitoring.
     2. Reactive test - three accelerations of FHR 15 beats/min above baseline FHR, lasting for 15 sec or more, over 20 min time period.
     3. Nonreactive test - no accelerations or acceleration less than 15 beats/min above baseline FHR. May indicate fetal jeopardy. V/S to differentiate hypoxia from fetal sleep.
     4. Unsatisfactory test - data that cannot be interpreted or inadequate fetal activity; repeat.
   • Contraction stress test (CST); oxytocin challenge test (OCT)
     1. Correlates fetal heart rate response to spontaneous or induced uterine contractions.
     2. Requires electronic monitoring.
     3. Indicator of uteroplacental sufficiency.
     4. Identifies pregnancies at risk for fetal compromise from uteroplacental insufficiency.
     5. Increasing doses of oxytocin are administered to stimulate uterine contractions until 3 in 10-minute period.
     6. Interpretation: negative results indicate absence of late decelerations with all contractions.
     7. Positive results indicate late FHR decelerations with contractions.
     8. Nipple stimulation (breast self-stimulation test) may also release enough systemic oxytocin to contract uterus to obtain CST
   • Biophysical profile (BPP)
     1. Observation by ultrasound of four variables for 30 min and results of nonstress testing:
        • Fetal body movements.
        • Fetal tone.
        • Amniotic fluid volume.
        • Fetal breathing movements.
     2. Variables are scored at 2 for each variable if present; score of 0 if not present; score of less than 6 is associated with perinatal mortality.
   • Ultrasound
     1. Noninvasive procedure involving passage of high-frequency sound waves through uterus to obtain data regarding fetal growth, placental positioning, and the uterine cavity.
     2. Purpose may include:
        • Pregnancy confirmation.
        • Fetal viability.
        • Estimation of fetal age.
        • BPD measurement (biparietal diameter)
        • Placenta location.
        • Detect fetal abnormalities.
        • Confirm fetal death.
        • Identify multifetal gestations.
        • Amniotic fluid index.
     3. No risk to mother with infrequent use. Fetal risk not determined on long-term basis.
   • Amniocentesis (Figure 4-6)
     1. Invasive procedure for amniotic fluid analysis to assess fetal lung maturity or disease; done after 14 weeks of gestation.
     2. Needle placed through abdominal-uterine wall; designated amount of fluid is withdrawn for examination.
     3. Empty bladder if gestation greater than 20 weeks.
     4. Risk of complications less than 1%. Ultrasound always precedes this procedure.
     5. Possible complications: onset of contractions; infections (probably amnionitis); placental punctures; cord puncture; bladder or fetal puncture.
     6. Advise women to observe and report the following to physician: fetal hypoactivity or hyperactivity, vaginal bleeding, vaginal discharge (clear or colored), signs of labor, signs of infection.
   • Analysis of amniotic fluid
     1. Chromosomal studies to detect genetic aberrations.
     2. Biochemical analysis of fetal cells to detect inborn errors of metabolism.
     3. Determination of fetal lung maturity by assessing lecithin-sphingoniyelin ratios.
     4. Evaluation of phospholipids (PG and PI); aids in determining lung maturity.
     5. Determination of creatinine levels, aids in determining fetal age. (Greater than 1.8 mg/dl indicates fetal maturity and the fetal age.)
     6. Assesses isoimmune disease.
     7. Assesses alpha-fetoprotein (AFP) HCG, and estriol (UE₃)levels for determination of neural tube defects and Down syndrome.
     8. Presence of meconium may indicate fetal hypoxia.
   • Chorionic villus sampling (CVS)
     1. Cervically invasive procedure.
     2. Advantage - results can be obtained after 10 weeks of gestation due to fast-growing fetal cells.
     3. Procedure - removal of small piece of tissue (chorionic villus) from fetal portion of placenta. Tissue reflects genetic makeup of fetus.
     4. Determines some genetic aberrations and allows for earlier decision for induced abortion (if desired) from abnormal results. Does not diagnose neural tube defects; CVS patients need further diagnoses with ultrasound and serum AFP levels.
     5. Protects “pregnancy privacy” because results can be obtained before the pregnancy is apparent and decisions can be made regarding abortion or continuation of gestation.
     6. Risks involve spontaneous abortion, infection, hematoma, intrauterine death, Rh isoimmunization, and fetal limb defects, if done before 9 weeks of gestation.