Fetal Well-Being and Biophysical Profile

Assessment of Fetal Well-Being

  • Assuring satisfactory growth and well-being of the fetus and mother throughout pregnancy.

  • Screening for high-risk cases and adverse maternal or intrauterine factors that may affect fetal growth.

  • Detecting congenital abnormalities or inborn metabolic disorders early in pregnancy that may not be compatible with life.

Assessment Methods

  • Doppler flow studies

  • Marker screening tests

  • Nuchal translucency screening

  • Ultrasonography

  • Alpha-fetoprotein analysis

  • Amniocentesis

  • Chorionic villus sampling (CVS)

  • Percutaneous umbilical blood sampling (PUBS)

  • Contraction stress test

  • Nonstress test

  • Biophysical profile

Ultrasound

  • Non-invasive.

  • Useful diagnostic tool in obstetrics.

  • Provides a continuous picture of the fetus and allows for measurements.

  • Standard component of prenatal care.

Doppler Flow Studies

  • Non-invasive, uses sound waves to examine blood flow in blood vessels.

  • Monitors fetal growth, placental function, cardiac function, and central venous pressure.

  • Detects fetal compromise.

Nuchal Translucency Screening

  • Performed between 11-14 weeks.

  • Measures subcutaneous accumulation of fluid behind the fetal neck using ultrasound.

  • Screens for fetal, chromosomal, and structural abnormalities.

Alpha-Fetoprotein Analysis (AFP)

  • AFP is a glycoprotein and biomarker.

  • Increases until 14-15 weeks, then progressively falls, entering maternal circulation.

  • AFP elevation may indicate neural tube defects, Turner syndrome, or hydrocephaly.

  • Low AFP levels may indicate Down syndrome (trisomy 21).

  • Test is done between 15-20 weeks using a maternal blood sample.

Marker Screening Tests

  • Assess risk of neural tube defects and Down syndrome (second trimester).

  • Measures specific substances in the pregnant woman's blood originating from the fetus, placental tissue, or both.

    • Triple marker screening: AFP, hCG, unconjugated estriol (15-20 weeks of gestation).

    • Quadruple screen: AFP, hCG, unconjugated estriol, inhibin A (15-20 weeks of gestation).

  • Sample is obtained from maternal serum.

  • These tests DO NOT diagnose a problem; they only signal that further testing should be done.

Amniocentesis

  • Transabdominal puncture of the amniotic sac to obtain a sample of amniotic fluid for analysis (most common in the second trimester).

  • Used to detect chromosomal abnormalities, neural tube defects, and hereditary metabolic defects.

  • May be performed in late pregnancy to check fetal well-being and diagnose fetal conditions, such as infection.

  • May be performed to check for fetal lung maturity if early delivery is expected.

Amniocentesis Procedure

  • Diagnostic, outpatient office procedure performed after 15 weeks under ultrasound guidance without anesthesia.

  • A needle is placed into a pocket of amniotic fluid containing desquamated living fetal cells (amniocytes).

Nursing Management: Before Amniocentesis

  • Explain the procedure and possible complications.

  • Obtain informed consent.

  • No special restriction on diet or activity prior to the procedure.

  • Stop anticoagulant medications.

  • Empty the bladder (2nd and 3rd trimester).

  • Fetal monitoring before the procedure.

  • Administer RhoGAM to Rh-negative mothers.

Nursing Management: During and After Amniocentesis

  • Monitor vital signs during the procedure.

  • Ultrasound will be performed.

  • Fetal monitoring after the procedure.

  • Monitor maternal vital signs and fetal heart rate every 15 minutes after the procedure.

  • Observe the puncture site for bleeding or drainage.

  • Provide support after the results.

  • Educate on danger signs (fever, leak of amniotic fluid, vaginal bleeding).

  • Advise rest at home and avoidance of strenuous activities for at least 24 hours.

Fetal Lung Maturity: Lecithin-Sphingomyelin Ratio (L/S Ratio)

  • Test of fetal amniotic fluid to assess for fetal lung maturity.

  • Lecithin and sphingomyelin are part of the surfactant.

  • Lecithin and sphingomyelin levels are equal until 32–33 weeks gestation.

  • After week 33, lecithin increases and sphingomyelin remains stable.

  • L/S ratio of 2 or higher indicates LUNG MATURITY.

  • L/S ratio of 1.5 or lower indicates Respiratory Distress Syndrome

Chorionic Villus Sampling (CVS)

  • Diagnostic test for chromosome abnormalities and other inherited disorders.

  • Involves removing some chorionic villi cells (embryonic origin) from the placenta.

  • Performed between 10 and 13 weeks of pregnancy, earlier than amniocentesis.

  • Cannot detect neural tube defects.

Chorionic Villus Sampling (CVS) Management

  • Administer RhoGAM to Rh-negative women.

  • Explain the procedure and danger signs.

Potential Risks of CVS

  • Bleeding and hemorrhage.

  • Miscarriage (0.5 to 1%, similar to amniocentesis).

  • Infection.

  • Risk for either digital or limb deficiency.

Noninvasive Prenatal Testing: Harmony Test

  • Can be performed as early as 10 weeks.

  • Analyzes cell-free DNA in maternal blood.

  • Indicates whether the fetus is at high or low risk of having trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), or trisomy 13 (Patau syndrome).

Nonstress Test (NST)

  • Noninvasive test that requires no initiation of contractions.

  • Indirect measure of uteroplacental function.

  • Recommended twice weekly after 28 weeks for clients with diabetes and other high-risk conditions.

  • The normal fetus produces characteristic fetal heart rate patterns in response to fetal movements, including acceleration of FHR with fetal movement.

Nonstress Test (NST) Procedure

  • The mother eats a meal to stimulate fetal activity and is placed in the left lateral recumbent position.

  • An external monitor is applied to her abdomen.

  • The client is handed an “Event Marker” with a button that she pushes every time she perceives fetal movement.

  • Obtain a baseline fetal monitor strip over 15 to 30 minutes.

Nonstress Test (NST) Interpretation

  • Reactive: 2 FHR accelerations from baseline of at least 15 bpm for at least 15 seconds within the 20-minute recording period.

  • Nonreactive: Absence of 2 FHR accelerations using the 15 by 15 criterion in a 20-minute time frame.

Contraction Stress Test (CST)

  • Also known as the oxytocin challenge test.

  • Performed at 34+ weeks of gestation.

  • Determines the fetal heart rate (FHR) response under stress (during contractions).

  • The goal is to achieve three uterine contractions in a 10-minute period without any FHR decelerations occurring.

  • Indicated in pregnancies in which placental insufficiency is suspected or an irregular FHR has been observed.

  • Risk of hyperstimulation of contractions and bradycardia.

Biophysical Profile

  • Screening test for utero-placental insufficiency.

  • Fetal biophysical activities are initiated, modulated, and regulated through the fetal nervous system.

  • The fetal CNS is very sensitive to diminished oxygenation.

  • Multiple variable assessment of fetal biophysical activities is more sensitive and reliable than the examination of a single parameter.

  • The profile is made up of five components:

    • Body movements

    • Fetal tone

    • Fetal breathing

    • Amniotic fluid volume

    • Nonstress test

Biophysical Profile - Scoring

  • Scored test with 5 components, each worth 2 points if present and 0 points if absent.

  • The duration of the test is 30 minutes.

  • Criteria to obtain a score (0-10 points):

    • Body movements: 3 or more discrete limb or trunk movements.

    • Fetal tone: one or more instances of full extension and flexion in the limb or trunk.

    • Fetal breathing: one or more fetal breathing movements of more than 30 seconds.

    • Amniotic fluid volume: one or more pockets of fluid measuring 2cm.

    • NST: Reactive= 2 points, nonreactive= 0 points.

Normal Biophysical Profile Score

  • 3 or more body movements

  • One or more instances of full limb or trunk extension and flexion

  • Presence of at least one breathing movement

  • One or more pockets of amniotic fluid volume (2 cm or more)

  • A reactive non-stress test

Biophysical Profile - Interpretation

  • Score of 8 to 10 is considered normal if the amniotic fluid is adequate.

  • Score of 6 or 5: suspicious, probably indicating a compromised fetus, further investigation of fetal well-being is needed.

  • Score of 4 or less is abnormal.

Biophysical profile - Nursing Management

  • Explain why the test is needed

  • Offer support

  • Answer client questions