Biophysical profile

A biophysical profile is a prenatal test which is used to check on a baby's well-being. The test combines the fetal heart rate monitoring (NST- Non Stress Test) and fetal ultrasound to evaluate a Fetal heart rate, movements, breathing, muscle tone and amniotic fluid level.

1. METRO COLLEGE OF NURSING BIOPHYSICAL PROFILE SANDHYA KUMARI Nursing Tutor (OBG) MCON, Greater Noida

2. INTRODUCTION It is a technique employed to forecast fetal well-being focus on fetal biophysical findings that include heart rate, movement, breathing, and amniotic fluid production It contains 5 parameters; non stress test (NST), fetal breathing, fetal movements, muscle tone and amniotic fluid volume Modified Biophysical Profile consists of NST and ultrasono graphically determined amniotic fluid index (AFI) Modified BPP is considered abnormal (non reassuring) when the NST is non-reactive and/or the AFI is < 5. The BPP is most common in the third trimester

3. DEFINITION The biophysical profile is a test used to evaluate the well-being of the fetus . The biophysical profile uses ultrasound and cardiotocography (CTG), also known electronic fetal heart rate monitoring, to examine the fetus . There are five components measured during the biophysical examination. A score of 2 points is given for each component that meets criteria as listed in the table below. The test is continued until all criteria are met or 30 minutes have elapsed. The points are then added for a possible maximum score of 10.

4. NONSTRESS TEST Currently, non stress test is the most widely used primary testing method for assessment of fetal well-being It describes FHR acceleration in response to fetal movement as a sign of fetal health Involved the use of Doppler-detected FHR acceleration coincident with fetal movements perceived by the mother As hypoxia develops, these fetal heart rate accelerations diminish

5. NORMAL RESULT T wo or more accelerations that peak at 15 bpm or more above baseline, each lasting 15 seconds or more, and all occurring within 20 minutes of beginning the test A 40-minute or longer tracing to account for fetal sleep cycles should be performed before concluding that there was insufficient fetal reactivity 1 acceleration was just as reliable as 2 in predicting healthy fetal status Also accelerations with or without fetal movements may be accepted

6. ABNORMAL RESULT Baseline oscillation of less than 15 bpm, A bsent accelerations, L ate decelerations with spontaneous uterine contractions Abnormal results were associated consistently with evidence of utero placental pathology

7. EXAMPLE IUGR Oligohydramnios Meconium Interval between testing set at 7 days; but more frequent testing is advocated for women with post-term pregnancy, multifetal gestation, type 1 diabetes mellitus, IUGR, or gestational hypertension In these circumstances, twice-weekly tests, with additional testing is advised

8. FETAL MOVEMENTS Passive unstimulated fetal activity commences as early as 7 weeks’ gestation and becomes more sophisticated and coordinated by the end of pregnancy Between 20 and 30 weeks, general body movements become organized, and by 36 weeks behavioural states are established in most normal foetuses

9. Four fetal behavioural states described State 1F is a quiescent state; quiet sleep, with a narrow oscillatory bandwidth of the FHR   State 2F includes frequent gross body movements, continuous eye movements, and wider oscillation of the FHR. It is analogous to REM or active sleep in the neonate   State 3F includes continuous eye movements in the absence of body movements and no heart rate accelerations State 4F is one of vigorous body movement with continuous eye movements and heart rate accelerations. This state corresponds to the awake state in newborns

10. CONTINUE State 4F is one of vigorous body movement with continuous eye movements and heart rate accelerations. This state corresponds to the awake state in newborns Fetuses spend most of their time in states 1F and 2F (>75% at 38 weeks) Mean length of the quiet or inactive state for term fetuses was 23 minutes (up to 75min) Amniotic fluid volume is another important determinant of fetal activity Perception of 10 fetal movements in up to 2 hours is considered normal.

11. FETAL BREATHING The first are gasps or sighs, which occurred at a frequency of 1 to 4 per minute The second, irregular bursts of breathing, occurred at rates up to 240 cycles per minute These latter rapid respiratory movements were associated with REM sleep Diurnal variation, because breathing substantively diminishes during the night But, increases somewhat following maternal meals Total absence of breathing was observed in some normal fetuses for up to 122 minutes, indicating fetal evaluation to diagnose absent respiratory motion may require long periods of observation.  

12. AMNIOTIC FLUID VOLUME Decreased utero placental perfusion may lead to diminished fetal renal blood flow, decreased urine production, and ultimately, oligohydramnios Amniotic fluid index < 5 cm or a maximum deepest vertical pocket < 2 cm are acceptable criteria for diagnosis of oligohydramnios Normal; ≥ 1 pocket measuring 2 cm in two perpendicular planes (2 × 2 cm pocket).

13. FETAL MUSCLE TONE Normal; ≥ 1 episode of extension (limb or trunk) with return of flexion. The ability to flex and extend an arm or leg, measured by counting quick, jerky movements.

14. Component   Normal  (2 points) Abnormal  (0 points) Fetal Breathing Movements One or more episodes of fetal breathing lasting at least 30 seconds within 30 minutes. No episodes of fetal breathing movements lasting at least 30 seconds during a 30 minute period of observation. Gross Body Movement 3 or more discrete body or limb movements within 30 minutes Less than 3 body or limb movements in 30 minutes Fetal Tone One or more episodes of active extension and flexion of a fetal extremity OR opening and closing of the hand within 30 minutes Slow extension with no return or slow return to flexion of a fetal extremity  OR no  fetal movement Amniotic Fluid  Volume A single deepest vertical pocket of amniotic fluid measures greater than 2 centimeters . is present A single deepest vertical pocket of amniotic fluid measures 2 centimeters or less Non-stress test  (NST) Reactive  Nonreactive

15. CONTINUE Amniotic Fluid Volume:   Measured as the vertical measurement , in centimeters , of the single deepest pocket of amniotic fluid with a transverse measurement of 1 cm or more wide  without fetal small parts or umbilical cord Reactive:   Two or more fetal heart rate accelerations that peak (but do not necessarily remain) at least 15 beats per minute above the baseline and last at least 15 seconds from baseline to baseline during 20 minutes of observation Nonreactive:   Less than two accelerations of fetal heart rate as described above after 40 minutes of observation

16. INTERPRETATION OF THE SCORE 8-10; no fetal asphyxia, repeat weekly 6; suspected chronic asphyxia, if >36 weeks deliver, if less repeat test in 4-6hours 4 and below; strongly suspect asphyxia, if >36weeks deliver, if not repeat after 4-6 hours for 120minutes, persistent score <5 deliver regardless

17. CONTRACTION STRESS TEST Formerly known as oxytocin challenge test Intravenous diluted oxytocin was used to stimulate contractions, and the FHR response was recorded The criterion for a positive test result, that is, an abnormal result, was uniform repetitive late fetal heart rate decelerations (which could be the result of utero placental insufficiency) Nipple stimulation to induce uterine contractions is usually successful for contraction stress testing 2-minute nipple stimulation ideally will induce a pattern of 3 contractions per 10 minutes, if not after 5 minutes, retry, if unsuccessful, diluted oxytocin.

18. ULTRASONOGRAPHY Low power sound: 100 mW Frequency:> 20,000/cycle Uses: Diagnose pregnancy at 6 weeks Locate placenta Diagnose fetal abnormalities Establish fetal sex

19. CONTINUE Discover problems Oligo/polyhydramnios Ectopic pregnancy Miscarriage Placenta previa PROM Down’s syndrome , NTDs, diaphragmatic hernia

20. CONTINUE Predict maturity of fetus Crown to rump length For dating, accuracy is +/- 3days (7-10 weeks) +/- 5days(10-14wks) Bi parietal diameter(most reliable at 12-20wks) +/- 5-7 days(16 weeks) +/- 3weeks >28 weeks

21. CONTINUE Bi parietal diameter (most reliable at 12-20wks) +/- 5-7 days (16 weeks) +/- 3weeks >28 weeks Cephalic index=BPD/ occipito frontal diameter Normal is 0.74-0.83

22. CONTINUE Head Circumference=(BPD+OFD ) Used to determine: Gestational age IUGR Microcephaly  

23. CONTINUE Abdominal Circumference Used from 16 weeks to term To determine gestational age Femur length Obtained as early as 10 weeks

24. NURSE’S RESPONSIBILITY Full bladder Draping Towel roll under her right buttock No risk to fetus from procedure

25. MODIFIED BIOPHYSICAL PROFILE NST +AFI: Abnormal when one / both is abnormal Time -20 minutes   Procedure: Standard NST No acceleration within 5 min 1-2 sec stimulation ( upto 3 times) Normal :2 acceleration within 10 min

26. GUIDELINES If both normal: weekly fetal surveilance If both abnormal: >36 weeks: delivery <36 weeks : doppler , BPP, CST If AFI less : search for placental insufficiency If NST nonreactive: doppler , CST, BPP

27. CT SCAN Better to be avoided in pregnancy MRI SCAN Obstetric applications Known/suspected Hydatidiform mole Placenta previa Fetal anomalies IUGR

28. CONCLUSION Antepartum management of high-risk pregnancies involves a balance of risks. Early delivery to minimize the morbidity and mortality associated with the high-risk condition may lead to severe morbidity or even mortality as a result of prematurity complications. Fetal surveillance tests have been developed to assess well-being at the time of the test and the statistical likelihood of future fetal well-being during a specified interval of time. In the USA the NST is widely used for primary surveillance of fetal well-being in high-risk pregnancies