Downloaded 120 times
![CST: Interpretation
Cunningham, F., & Williams, J. (2014). Williams obstetrics. (24th ed. / [edited by] F. Gary Cunningham et al.
ed.). New York ; London: McGraw-Hill Medical.
Normal
Abnormal](https://image.slidesharecdn.com/02-160613133700/85/Antepartum-fetal-testing-12-320.jpg)
![4.Biophysical profile (BPP)
◦ More accurate.
◦ Consist 5 assessments
Cunningham, F., & Williams, J. (2014). Williams obstetrics. (24th ed. / [edited by] F. Gary Cunningham et al. ed.). New York ; London:
McGraw-Hill Medical.](https://image.slidesharecdn.com/02-160613133700/85/Antepartum-fetal-testing-13-320.jpg)
![Fetal breathing
◦Characteristic:
◦ Paradoxical
chest wall
movement
Cunningham, F., & Williams, J. (2014). Williams obstetrics. (24th ed. /
[edited by] F. Gary Cunningham et al. ed.). New York ; London:
McGraw-Hill Medical.](https://image.slidesharecdn.com/02-160613133700/85/Antepartum-fetal-testing-14-320.jpg)
![Interpretation of BPP
Cunningham, F., & Williams, J. (2014). Williams obstetrics. (24th ed. / [edited by] F. Gary Cunningham et al. ed.). New York ; London:
McGraw-Hill Medical.](https://image.slidesharecdn.com/02-160613133700/85/Antepartum-fetal-testing-15-320.jpg)
![References
◦ Beckmann, C., Herbert, W., Laube, D., Ling, F., Smith, R., & American College of
Obstetricians Gynecologists. (2014). Obstetrics and gynecology (7th ed.).
◦ http://www.uptodate.com/contents/nonstress-test-and-contraction-stress-
test?source=see_link§ionName=Nonstress+test&anchor=H10#H10
◦ Callahan, T., & Caughey, A. (2007). Blueprints obstetrics & gynecology (4th ed. /
Tamara L. Callahan, Aaron B. Caughey. ed., Blueprints). Philadelphia ; London:
Lippincott Williams & Wilkins.
◦ https://www.youtube.com/watch?v=NJEAQSyGmI0
◦ http://www.uptodate.com/contents/nonstress-test-and-contraction-stress-
test?source=see_link§ionName=Nonstress+test&anchor=H10#H13
◦ Cunningham, F., & Williams, J. (2014). Williams obstetrics. (24th ed. / [edited by] F.
Gary Cunningham et al. ed.). New York ; London: McGraw-Hill Medical.
◦ http://www.girldocs.com/obsterical/fetal-movement-counts/
◦ https://www.uptodate.com/contents/decreased-fetal-movement-diagnosis-
evaluation-and-
management?source=search_result&search=fetal+movement&selectedTitle=1~127](https://image.slidesharecdn.com/02-160613133700/85/Antepartum-fetal-testing-19-320.jpg)
![CHOICE OF TEST
◦ depends on multiple factors, including gestational age (up to 50 percent
of NSTs are not reactive in healthy 24 to 28 weeks fetuses [47]),
availability, desire for fetal biometry or follow-up of a congenital
anomaly, ability to monitor the fetal heart rate (eg, the NST and CST may
not be interpretable in a fetus with an arrhythmia), and cost.
◦ Doppler assessment of the umbilical artery should be used to monitor
the growth-restricted fetus, given its proven efficacy in reducing
perinatal death in this setting when used with standard fetal testing
(NST, BPP) and appropriate intervention [48]. It has only modest ability
to predict fetal compromise in other high-risk pregnancies](https://image.slidesharecdn.com/02-160613133700/85/Antepartum-fetal-testing-25-320.jpg)
Uploaded bykr
Antepartum fetal testing
This document discusses antepartum fetal testing. The goals of testing are to assess fetal well-being, identify fetuses at risk, and allow for early intervention to prevent intrauterine death or complications from asphyxia. Tests discussed include fetal movement counting, non-stress tests, contraction stress tests, biophysical profiles, and umbilical artery Doppler. Each test evaluates the fetus in a different way such as heart rate patterns, response to contractions, or blood flow. Test results are used to monitor high risk pregnancies and detect any abnormalities.
More Related Content
Similar to Antepartum fetal testing
Antepartum fetal testing
- 1.
- 2. Goals of antepartumfetal testing ◦ To assess fetal well-being and prediction of future fetal condition ◦ To prevent/ identify fetuses at risk ◦ Intrauterine death (IUD) ◦ Complications of intrauterine asphyxia ◦ For early intervention to prevent IUD or complication of IU asphyxia
- 3. Tests ◦ Subjective maternalperception of fetal activity ◦ Fetal movement counting ◦ Objective tests ◦ Non stress test (NST) ◦ Contraction stress test (CST) ◦ Biophysical profile (BPP) ◦ Umbilical artery blood flow velocity
- 5. 1. Fetal movementcounting ◦ Clinically important parameter of fetal wellbeing ◦ The EASIEST & MOST AVAILABLE ◦ Assessed by mother subjectively ◦ Number of movements “kick counts”/ hour
- 7. 2. Non stresstest (NST) ◦ Study the response of FHR to fetal movements. TEST FOR FETAL CONDITION
- 8. Non stress test:Prep
- 9. Non stress test:Result ◦ Normal/R ◦ 2 accelerations of the FHR in 20 min ◦ At least 15 beats above the baseline HR ◦ Last for at least 15 seconds ◦ Abnormal/NR ◦ No FHR accelerations over a 40 min period ◦ Presence of decelerations with fetal movement
- 10.
- 11. 3. Contraction StressTest ◦ Measure fetal response to a transient reduction in fetal oxygen delivery during uterine contractions ◦ Induce with ◦ Nipple stimulation ◦ Infusion of dilute oxytocin solution 0.5 mU/min TEST OF UTEROPLACENTAL FUNCTION
- 12. CST: Interpretation Cunningham, F.,& Williams, J. (2014). Williams obstetrics. (24th ed. / [edited by] F. Gary Cunningham et al. ed.). New York ; London: McGraw-Hill Medical. Normal Abnormal
- 13. 4.Biophysical profile (BPP) ◦More accurate. ◦ Consist 5 assessments Cunningham, F., & Williams, J. (2014). Williams obstetrics. (24th ed. / [edited by] F. Gary Cunningham et al. ed.). New York ; London: McGraw-Hill Medical.
- 14. Fetal breathing ◦Characteristic: ◦ Paradoxical chestwall movement Cunningham, F., & Williams, J. (2014). Williams obstetrics. (24th ed. / [edited by] F. Gary Cunningham et al. ed.). New York ; London: McGraw-Hill Medical.
- 15. Interpretation of BPP Cunningham,F., & Williams, J. (2014). Williams obstetrics. (24th ed. / [edited by] F. Gary Cunningham et al. ed.). New York ; London: McGraw-Hill Medical.
- 16. Modified BPP ◦The mostpredictive of outcome: ◦Non stress test ◦Amniotic fluid index
- 17. ◦ Most commonlyused index: Systolic/diastolic ratio ◦ Quantify the flow velocity waveform. 5. Umbilical artery blood flow velocity
- 18. Conclusion ◦ Fetal wellbeing assessment are important in all pregnancy. ◦ AFT comprise few important tests that will benefit mostly towards high risk pregnancy. ◦ Also important for monitoring the fetal condition and early detection of fetal abnormalities.
- 19. References ◦ Beckmann, C.,Herbert, W., Laube, D., Ling, F., Smith, R., & American College of Obstetricians Gynecologists. (2014). Obstetrics and gynecology (7th ed.). ◦ http://www.uptodate.com/contents/nonstress-test-and-contraction-stress- test?source=see_link§ionName=Nonstress+test&anchor=H10#H10 ◦ Callahan, T., & Caughey, A. (2007). Blueprints obstetrics & gynecology (4th ed. / Tamara L. Callahan, Aaron B. Caughey. ed., Blueprints). Philadelphia ; London: Lippincott Williams & Wilkins. ◦ https://www.youtube.com/watch?v=NJEAQSyGmI0 ◦ http://www.uptodate.com/contents/nonstress-test-and-contraction-stress- test?source=see_link§ionName=Nonstress+test&anchor=H10#H13 ◦ Cunningham, F., & Williams, J. (2014). Williams obstetrics. (24th ed. / [edited by] F. Gary Cunningham et al. ed.). New York ; London: McGraw-Hill Medical. ◦ http://www.girldocs.com/obsterical/fetal-movement-counts/ ◦ https://www.uptodate.com/contents/decreased-fetal-movement-diagnosis- evaluation-and- management?source=search_result&search=fetal+movement&selectedTitle=1~127
- 20.
- 25. CHOICE OF TEST ◦depends on multiple factors, including gestational age (up to 50 percent of NSTs are not reactive in healthy 24 to 28 weeks fetuses [47]), availability, desire for fetal biometry or follow-up of a congenital anomaly, ability to monitor the fetal heart rate (eg, the NST and CST may not be interpretable in a fetus with an arrhythmia), and cost. ◦ Doppler assessment of the umbilical artery should be used to monitor the growth-restricted fetus, given its proven efficacy in reducing perinatal death in this setting when used with standard fetal testing (NST, BPP) and appropriate intervention [48]. It has only modest ability to predict fetal compromise in other high-risk pregnancies
- 30. ◦ Antepartum Fetaltesting ◦ Oligohydramnios & IUGR ◦ Third trimester bleeding (Placenta Previa vs Placenta Abruption) ◦ Molar Pregnancy ◦ Cervical Cancer ◦ Polycystic Ovarian Disease ◦ Infertility
Editor's Notes
- #2 Antepartum - occurring before childbirth http://www.uptodate.com/contents/overview-of-antepartum-fetal-surveillance?source=search_result&search=antenatal+fetal+testing&selectedTitle=1~150
- #3 Look for fetal health Identify fetuses at risk of IUD. Identify fetuses at risk of other complications of IU asphyxia and intervene to prevent these adverse outcomes.
- #4 Number of movements each day/ Contraction stress test (CST) – or they called Oxytocin challenge test (OCT) if oxytocin is used
- #5 Diabetes – Pregestational diabetes, gestational diabetes treated with anti-hyperglycemic drugs, or gestational diabetes poorly controlled with nutritional therapy alone Hypertensive disorders Fetal growth restriction Twin pregnancy Postterm pregnancy Decreased fetal activity Systemic lupus erythematosus Antiphospholipid syndrome Sickle cell disease Alloimmunization Oligohydramnios or polyhydramnios Prior fetal demise Preterm premature rupture of membranes Other – Nonimmune hydrops, maternal cyanotic heart disease, poorly controlled maternal hyperthyroidism, and maternal vascular diseases are associated with an increased risk of fetal demise and generally considered appropriate indications for antenatal fetal testing.
- #6 Cardif “count 10” formula The pt is instructed to report if: < 10 mvmt occur during 12 hours on 2 consecutive days No mvmt perceived even after 12 hours in a single day Fetal movement counting — Objective maternal assessment of fetal movements is based on evidence that fetal movement decreases in response to hypoxemia Maternal perception of fetal movement typically begins in the second trimester at around 16 to 20 weeks of gestation. Indirect measure of CNS integrity and function.
- #7 Can start at 24 weeks. Before that useless. Diabetid: start surveillance at 32 weeks.
- #8 Normal/Reactive/Reassuring if there are two accelerations of the FHR in 20 minutes that are at least 15 beats above the baseline heart rate and last for at least 15 seconds (Blueprint 8) 1 small boxes is 10 sec. At least 2 small boxes Usually performed after 30 weeks after fetal NS maturation Non reactive – cause by interrupted fetal oxygenation to the point of metabolic academia Also cause by fetal immaturity, quiet fetal sleep, maternal smoking (women who smoke should not smoke proximate to an NST), fetal neurologic or cardiac anomalies, sepsis, or maternal ingestion of drugs with cardiac effects [30]. Sleep is a common and benign cause of nonreactivity FHR = Fetal heart rate
- #9 Contraction stress test — The contraction stress test (CST) is based on the fetal response to a transient reduction in fetal oxygen delivery during uterine contractions. If the fetus becomes hypoxemic (fetal arterial pO2 below 20 mm Hg [16,17]), fetal chemoreceptors and baroreceptors, as well as sympathetic and parasympathetic influences, respond by reflex slowing of the fetal heart rate (FHR), which may manifest clinically as late decelerations (waveform 1 and waveform 2). Performance of the CST, as well as its interpretation and use, are described in detail separately. The CST is seldom performed given the wide availability of other tests (eg, nonstress test, biophysical profile) that don’t have its drawbacks. Major drawbacks related to use of the CST include the need to stimulate contractions with intravenous oxytocin, the contraindication to inducing contractions in some conditions (eg, placenta previa), and the high false-positive rate (ie, fetus goes on to tolerate labor without FHR changes necessitating intervention). In contrast, the false-negative rate (ie, rate of antepartum stillbirth within one week of a negative test) is very low (table 1), thus providing reassurance of adequate fetal oxygenation after a normal test result
- #11 12 minutes strip
- #12 Normal test can become abnormal if fetal condition deteriorates
- #13 variable decelerations, if nonrepetitive and brief—less than 30 seconds— do not indicate fetal compromise or the need for obstetrical intervention repetitive variable decelerations— at least three in 20 minutes—even if mild, have been associated with an increased risk of cesarean delivery for fetal distress Decelerations lasting 1 minute or longer have been reported to have an even worse prognosis
- #14 CTG Put transducers for a baseline tracing for 10 to 20 minutes If at least 3 spontaneous contraction of 40 sec or longer are present in 10 min, no uterine stimulation is necessary. If there is fewer than 3 contraction in 10 min -> do uterine stimulation. Start with nipple stimulation by rubbing the one nipple tru her clothing for 2 min. or until contraction begin. If not after 5 min interval, retry nipple stimulation to schieve the desired pattern. If unsuccessful induce uterine contractions This test generally repeated on a weekly basis, and the investigators concluded that negative contraction stress results, that is normal results, shows fetal is healthy. If positive/+ = Also suggestive cord compression, suggesting oligohydramnios, which is often a concomitant of placental insufficiency. Disadv: Req 90 min to complete. n weekly basis
- #15 If have late decelerations = uteroplacental insufficiency
- #16 More accurate for assessing fetal health than single element. tests require 30 to 60 minutes of examiner time. biophysical test scores were higher if a test was performed in late evening (8 to 10 pm) compared with 8 to 10 am. biophysical score of 0 was almost invariably associated with significant fetal acidemia, whereas a normal score of 8 or 10 was associated with normal pH An equivocal test result—a score of 6—was a poor predictor of abnormal outcome. As the abnormal score decreased from 2 or 4 down to a very abnormal score of zero, this was a progressively more accurate predictor of abnormal fetal outcome.
- #17 Suggested that fetal respiratory rate decreased in conjunction with increase respiratory volume at 33 – 36 weeks and coincidental with lung maturity Can be visualize by ultrasound. Factor affecting fetal resp. mvmt – hypoglycemia, sound stimuli, cigar smoking, amniocentesis, impeding preterm labor Should perform 24 hour observation using U/S to char fetal breathing patterns during the last weeks of pregnancy
- #18 Amniotic fluid volume — In the hypoxemic fetus, cardiac output is redirected to the brain, heart, and adrenals and away from less vital organs, such as the kidney; the reduction in renal perfusion leads to decreased fetal urine production, which may result in decreased amniotic fluid volume (oligohydramnios) over time. This is the rationale for amniotic fluid evaluation as part of fetal assessment. (See "Oligohydramnios".) Sonographic determination of the single deepest amniotic fluid pocket (SDP) is the preferred method of AFV assessment. The SDP and the amniotic fluid index (AFI) method are equivalent in their prediction of adverse outcome in singleton pregnancies, but use of the AFI increases the number of labor inductions and cesarean deliveries without any improvement in perinatal outcome. Assessment of AFV, as well as its interpretation and use, are described in detail separately. (See "Assessment of amniotic fluid volume".)
- #19 Amniotic fluid index. Measure the depth of amniotic fluid at 4 quadrants To simplify the examination Reduce the time necessary to complete testing by focusing on those components of the BPP AFI = Normal is from 5 cm to 24 cm
- #20 Normal is from 5 cm to 24 cm
- #21 Measure the velocity of blood flow in the Umbilical artery As the resistance increases, diastolic flow decreases and may become absent or reversed -> Increase the S/D ratio Provide assessment on blood perfusion of the fetoplacental unit Eg: in IUGR secondary to uteroplacental insufficiency can show reversed end- systolic flow -> may suggest impending fetal demise Umbilical artery — Umbilical artery Doppler assessments are most useful for monitoring fetuses with early-onset growth restriction due to uteroplacental insufficiency [27]. The umbilical artery waveform pattern is compatible with a low-resistance system: forward blood flow occurs throughout the cardiac cycle. Umbilical artery flow velocity waveforms of normally growing fetuses are characterized by high-velocity diastolic flow, whereas in growth-restricted fetuses, umbilical artery diastolic flow is diminished, absent, or even reversed in severe cases [28]. This progressive reduction of umbilical artery diastolic flow is associated with worsening destruction of placental villus vasculature [29]. In the growth-restricted fetus, absent or reversed end diastolic flow is associated with fetal hypoxemia and acidemia, and increased perinatal morbidity and mortality [25,29,30]. The technique for Doppler interrogation of the umbilical artery, as well as interpretation and use of umbilical artery Doppler, are described in detail separately. (See "Doppler ultrasound of the umbilical artery for fetal surveillance".) The American College of Obstetricians and Gynecologists (ACOG) practice guidelines support the use of umbilical artery Doppler assessments in the management of suspected intrauterine growth restriction, but not for normally grown fetuses [11]. When monitoring the growth-restricted fetus, umbilical artery Doppler should be used with standard fetal surveillance (nonstress test and/or biophysical profile score). (See "Fetal growth restriction: Evaluation and management", section on 'Umbilical artery'.) There is no strong evidence to support umbilical artery Doppler surveillance in settings other than suspected fetal growth restriction. In a systematic review of 16 randomized trials including over 10,000 “high-risk” patients where the definition of “high risk” varied among trials, use of Doppler ultrasound resulted in a variable decrease in perinatal mortality (OR 0.71, 95% CI 0.52-0.98, 1.2 versus 1.7 percent, number needed to treat 203) [31]. In addition, a systematic review of five randomized trials including over 14,000 low-risk or unselected obstetrical patients found routine umbilical artery Doppler screening did not improve perinatal outcomes [32].
- #24 Middle cerebral artery — Doppler assessment of the fetal middle cerebral artery-peak systolic velocity is the best tool for monitoring for fetal anemia in at-risk pregnancies, such as those affected by Rhesus alloimmunization. (See "Management of pregnancy complicated by Rhesus (D) alloimmunization", section on 'Assess for severe anemia in fetuses at risk'.) Middle cerebral artery Doppler is under investigation as an additional tool for surveillance of pregnancies complicated by growth restriction. Its use in this setting is based on the premise that systemic blood flow in these fetuses is redistributed from the periphery to the brain and Doppler measurement of flow velocity in the fetal middle cerebral artery can detect this brain-sparing effect [22,33-35].
- #25 Fetal veins — Venous Doppler parameters may be abnormal due to several abnormalities in cardiovascular function. These include decreased cardiac compliance and contractility, marked elevations in cardiac afterload, and abnormalities of cardiac rhythm and rate. The clinical utility of venous Doppler velocimetry is therefore greatest in fetal conditions with cardiac manifestations and/or marked placental insufficiency. These conditions include fetal growth restriction due to placental insufficiency [36,37], twin-twin transfusion [38], fetal hydrops [39], and fetal arrhythmia [40,41]. The fetal precordial veins (ductus venosus and inferior vena cava) and the umbilical vein are the vessels most commonly evaluated in clinical practice, although flow velocity waveforms have been reported for many other venous vessels. Blood flow in the umbilical vein is continuous in normal pregnancies >15 weeks of gestation. In pathological states, such as fetal growth restriction, flow in the umbilical vein may be pulsatile, which reflects cardiac dysfunction related to increased afterload. The ductus venosus regulates oxygenated blood in the fetus [42] and is resistant to alterations in flow except in the most severely growth-restricted fetuses.
- #26 Uterine artery — A number of investigators have explored the use of uterine artery Doppler for third trimester fetal assessment among women with complicated pregnancies, but its role in these settings has not been clearly defined [43-45]. Impedance to flow in the uterine arteries normally decreases as pregnancy progresses. Failure of adequate trophoblast invasion and remodeling of maternal spiral arteries is characterized by a persistent high-pressure uterine circulation and increased impedance to uterine artery blood flow. Elevated resistance indices and/or persistent uterine artery notching at 22 to 24 weeks of gestation indicate reduced blood flow in the maternal compartment of the placenta and have been associated with development of preeclampsia, fetal growth restriction, and perinatal death [46]. (See "Fetal growth restriction: Diagnosis" and "Prediction of preeclampsia", section on 'Uterine artery Doppler velocimetry'.)
- #30 TIMING — Testing should begin as soon as an increased risk of fetal demise is identified and delivery for perinatal benefit would be considered if test results are abnormal. Observational data show that rates of stillbirth in nongrowth-restricted fetuses significantly rise between about 32 weeks and term [50]. (See "Nonstress test and contraction stress test" and "The fetal biophysical profile" and "Decreased fetal movement: Diagnosis, evaluation, and management".)
- #31 DURATION AND FREQUENCY — Fetal testing should be performed periodically until delivery if the clinical condition that prompted fetal surveillance continues to exist. A single normal test result is adequate if performed for a nonrecurring indication in an otherwise low-risk pregnancy (eg, reactive nonstress test after a minor motor vehicle accident and no signs of labor or vaginal bleeding). Testing is typically performed weekly, but the frequency is generally increased if there is a change in pregnancy status (eg, fetal growth percentile falls from 10th percentile to 3rd percentile, worsening preeclampsia) or in clinical settings considered to be very high risk (eg, fetal growth restriction with absent or reversed diastolic flow) [11]. There are no data from randomized trials on which to base recommendations for the optimum frequency of fetal monitoring (daily, every other day, twice per week, once per week). These decisions are based on expert opinion, clinical experience with similar high-risk pregnancies, and community standards.
- #32 MANAGEMENT OF ABNORMAL TEST RESULTS — Given the high rate of false-positive tests, an abnormal test result is generally followed by additional testing with a different test (eg, contraction stress test [CST] or biophysical profile [BPP] after a nonreactive nonstress test [NST]) to provide more information about fetal status. The clinical setting also needs to be considered. If a temporary maternal condition, such as diabetic ketoacidosis or acute bronchospasm, may account for the abnormal test result, prompt treatment of the maternal condition may also improve fetal oxygenation and lead to a normal test result on subsequent testing. In chronic conditions, clinical judgment guides management, taking into account factors such as gestational age (low threshold for delivery for an abnormal test result at term), severity of disease (eg, diabetes with poor glycemic control versus good glycemic control), progression of disease (eg, fetal growth falls from the 10th percentile to the 3rd percentile), and other available information (eg, decelerations, absent variability, or bradycardia on a nonreactive NST; BPP score 0 versus 4 or 6; absence of accelerations on a positive CST). If delivery is indicated by the specific clinical setting and test results, induction of labor is not contraindicated. After a positive CST, up to 40 percent of fetuses have been reported to tolerate labor without FHR changes necessitating intervention [51].
- #33 SUMMARY AND RECOMMENDATIONS ●The main goal of antepartum fetal surveillance is to identify the fetus that will benefit from early intervention, such as in utero resuscitation or delivery, and thereby prevent fetal death or neurologic injury. (See 'Introduction' above.) ●Antepartum testing is based on the premise that the fetus responds to hypoxemia with a detectable sequence of biophysical changes (figure 1). (See 'Physiological basis for fetal testing' above.) ●Antepartum fetal surveillance has had an established role in obstetrical practice since the 1970s, although its ability to improve pregnancy outcome has not been evaluated by large, well-designed randomized trials. (See 'Efficacy' above.) ●Antepartum fetal testing is indicated in "pregnancies in which the risk of antepartum fetal demise is increased.” (See 'Indications for fetal surveillance' above.) ●Techniques for assessment of fetal well-being (nonstress test, contraction stress test, biophysical profile, modified biophysical profile) are described in the table (table 1). (See 'Fetal assessment techniques' above.) ●The optimal choice of technique(s) for fetal assessment has not been determined and depends on multiple factors, including gestational age, availability, desire for fetal biometry or follow-up of a congenital anomaly, ability to monitor the fetal heart rate, and cost. The best evidence supports umbilical artery Doppler assessment for monitoring fetuses with early-onset growth restriction due to uteroplacental insufficiency, given its proven efficacy in reducing perinatal death in this setting when used with standard fetal testing (nonstress test, biophysical profile score) and appropriate intervention. It has only modest ability to predict fetal compromise in other high-risk pregnancies. (See 'Choice of test' above.) ●Antepartum fetal surveillance is initiated when an increased risk of fetal demise is identified and delivery for perinatal benefit would be considered if test results are abnormal. (See 'Timing' above.) ●Testing is typically performed weekly, but the frequency is generally increased if there is a change in pregnancy status or in clinical settings considered to be very high risk. (See 'Duration and frequency' above.) ●An abnormal test result is generally followed by additional testing with a different test, given the high rate of false-positive results (table 1). The clinical setting also needs to be considered. If a temporary maternal condition may account for the abnormal test result, prompt treatment of the maternal condition may also improve fetal oxygenation and lead to a normal test result on subsequent testing. In chronic conditions, clinical judgment guides management and needs to consider case specific factors. (See 'Management of abnormal test results' above.)