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Nonstress test and contraction stress test

David A Miller, MD
Section Editor
Charles J Lockwood, MD, MHCM
Deputy Editor
Vanessa A Barss, MD, FACOG


Fetal health is evaluated, in part, by assessment of fetal heart rate (FHR) patterns. The primary goal is to identify fetuses at risk of intrauterine death or neonatal complications and intervene (often by delivery) to prevent these adverse outcomes, if possible.

The nonstress test (NST) and the contraction stress test (CST) are used for antepartum FHR testing. An abnormal test (nonreactive NST, positive CST) is sometimes associated with adverse fetal or neonatal outcomes, while a normal test (reactive NST, negative CST) is usually associated with a neurologically intact and adequately oxygenated fetus. When interpreting these tests, the clinician needs to account for gestational age, prior results of fetal assessment, maternal conditions (including medications), and fetal condition (eg, growth restriction, anemia, arrhythmia).

The NST and CST will be reviewed here. Intrapartum fetal evaluation and additional techniques for assessing fetal health are discussed separately.

(See "Intrapartum fetal heart rate assessment".)

(See "The fetal biophysical profile".)

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Literature review current through: Nov 2017. | This topic last updated: Jan 20, 2017.
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  1. Parer JT. Fetal heart rate. In: Maternal Fetal Medicine: Principles and Practice, Creasy, Resnik (Eds), WB Saunders Company, Philadelphia 1999.
  2. Abboud T, Raya J, Sadri S, et al. Fetal and maternal cardiovascular effects of atropine and glycopyrrolate. Anesth Analg 1983; 62:426.
  3. Sadovsky G, Nicolaides KH. Reference ranges for fetal heart rate patterns in normoxaemic nonanaemic fetuses. Fetal Ther 1989; 4:61.
  4. Park MI, Hwang JH, Cha KJ, et al. Computerized analysis of fetal heart rate parameters by gestational age. Int J Gynaecol Obstet 2001; 74:157.
  5. Pillai M, James D. The development of fetal heart rate patterns during normal pregnancy. Obstet Gynecol 1990; 76:812.
  6. Electronic fetal heart rate monitoring: research guidelines for interpretation. National Institute of Child Health and Human Development Research Planning Workshop. Am J Obstet Gynecol 1997; 177:1385.
  7. Young BK, Katz M, Klein SA. Pregnancy after spinal cord injury: altered maternal and fetal response to labor. Obstet Gynecol 1983; 62:59.
  8. Antoine C, Young BK, Silverman F. Simultaneous measurement of fetal tissue pH and transcutaneous pO2 during labor. Eur J Obstet Gynecol Reprod Biol 1984; 17:69.
  9. Clifford G, Sameni R, Ward J, et al. Clinically accurate fetal ECG parameters acquired from maternal abdominal sensors. Am J Obstet Gynecol 2011; 205:47.e1.
  10. Cohen WR, Ommani S, Hassan S, et al. Accuracy and reliability of fetal heart rate monitoring using maternal abdominal surface electrodes. Acta Obstet Gynecol Scand 2012; 91:1306.
  11. Reinhard J, Hayes-Gill BR, Schiermeier S, et al. Intrapartum signal quality with external fetal heart rate monitoring: a two way trial of external Doppler CTG ultrasound and the abdominal fetal electrocardiogram. Arch Gynecol Obstet 2012; 286:1103.
  12. Macones GA, Hankins GD, Spong CY, et al. The 2008 National Institute of Child Health and Human Development workshop report on electronic fetal monitoring: update on definitions, interpretation, and research guidelines. Obstet Gynecol 2008; 112:661.
  13. Practice bulletin no. 145: antepartum fetal surveillance. Obstet Gynecol 2014; 124:182.
  14. Freeman RK, Anderson G, Dorchester W. A prospective multi-institutional study of antepartum fetal heart rate monitoring. I. Risk of perinatal mortality and morbidity according to antepartum fetal heart rate test results. Am J Obstet Gynecol 1982; 143:771.
  15. Grivell RM, Alfirevic Z, Gyte GM, Devane D. Antenatal cardiotocography for fetal assessment. Cochrane Database Syst Rev 2015; :CD007863.
  16. Freeman RK, Anderson G, Dorchester W. A prospective multi-institutional study of antepartum fetal heart rate monitoring. II. Contraction stress test versus nonstress test for primary surveillance. Am J Obstet Gynecol 1982; 143:778.
  17. Olofsson P, Sjöberg NO, Solum T. Fetal surveillance in diabetic pregnancy. II. The nonstress test versus the oxytocin challenge test. Acta Obstet Gynecol Scand 1986; 65:357.
  18. Platt LD, Walla CA, Paul RH, et al. A prospective trial of the fetal biophysical profile versus the nonstress test in the management of high-risk pregnancies. Am J Obstet Gynecol 1985; 153:624.
  19. Rouse DJ, Owen J, Goldenberg RL, Cliver SP. Determinants of the optimal time in gestation to initiate antenatal fetal testing: a decision-analytic approach. Am J Obstet Gynecol 1995; 173:1357.
  20. Evertson LR, Gauthier RJ, Schifrin BS, Paul RH. Antepartum fetal heart rate testing. I. Evolution of the nonstress test. Am J Obstet Gynecol 1979; 133:29.
  21. Brown R, Patrick J. The nonstress test: how long is enough? Am J Obstet Gynecol 1981; 141:646.
  22. Guidelines for perinatal care, 7th ed, American Academy of Pediatrics and the American College of Obstetricians and Gynecologists, Washington, DC 2012.
  23. Nageotte MP, Towers CV, Asrat T, et al. The value of a negative antepartum test: contraction stress test and modified biophysical profile. Obstet Gynecol 1994; 84:231.
  24. Nageotte MP, Towers CV, Asrat T, Freeman RK. Perinatal outcome with the modified biophysical profile. Am J Obstet Gynecol 1994; 170:1672.
  25. Miller DA, Rabello YA, Paul RH. The modified biophysical profile: antepartum testing in the 1990s. Am J Obstet Gynecol 1996; 174:812.
  26. Hoskins IA, Frieden FJ, Young BK. Variable decelerations in reactive nonstress tests with decreased amniotic fluid index predict fetal compromise. Am J Obstet Gynecol 1991; 165:1094.
  27. Begum F, Buckshee K. Foetal compromise by spontaneous foetal heart rate deceleration in reactive non-stress test and decreased amniotic fluid index. Bangladesh Med Res Counc Bull 1998; 24:60.
  28. Glantz C, D'Amico ML. Lack of relationship between variable decelerations during reactive nonstress tests and oligohydramnios. Am J Perinatol 2001; 18:129.
  29. Judge NE, Mann LI, Lupe P, Amini S. Clinical associations of variable decelerations during reactive nonstress tests. Obstet Gynecol 1989; 74:351.
  30. Phelan JP, Lewis PE Jr. Fetal heart rate decelerations during a nonstress test. Obstet Gynecol 1981; 57:228.
  31. Bruce SL, Petrie RH, Davison J. Prediction of abnormal umbilical cord position and intrapartum cord problems from the nonstress test. Diagn Gynecol Obstet 1980; 2:47.
  32. Meis PJ, Ureda JR, Swain M, et al. Variable decelerations during nonstress tests are not a sign of fetal compromise. Am J Obstet Gynecol 1986; 154:586.
  33. Manning FA, Snijders R, Harman CR, et al. Fetal biophysical profile score. VI. Correlation with antepartum umbilical venous fetal pH. Am J Obstet Gynecol 1993; 169:755.
  34. Oncken C, Kranzler H, O'Malley P, et al. The effect of cigarette smoking on fetal heart rate characteristics. Obstet Gynecol 2002; 99:751.
  35. Pillai M, James D. Behavioural states in normal mature human fetuses. Arch Dis Child 1990; 65:39.
  36. Tan KH, Sabapathy A. Maternal glucose administration for facilitating tests of fetal wellbeing. Cochrane Database Syst Rev 2012; :CD003397.
  37. Tan KH, Sabapathy A, Wei X. Fetal manipulation for facilitating tests of fetal wellbeing. Cochrane Database Syst Rev 2013; :CD003396.
  38. Moffatt FW, van den Hof M. Semi-Fowler's positioning, lateral tilts, and their effects on nonstress tests. J Obstet Gynecol Neonatal Nurs 1997; 26:551.
  39. Devoe LD, Murray C, Youssif A, Arnaud M. Maternal caffeine consumption and fetal behavior in normal third-trimester pregnancy. Am J Obstet Gynecol 1993; 168:1105.
  40. Mulder EJ, Tegaldo L, Bruschettini P, Visser GH. Foetal response to maternal coffee intake: role of habitual versus non-habitual caffeine consumption. J Psychopharmacol 2010; 24:1641.
  41. Buscicchio G, Lorenzi S, Tranquilli AL. The effects of different concentrations of cocoa in the chocolate intaken by the mother on fetal heart rate. J Matern Fetal Neonatal Med 2013; 26:1465.
  42. Kilpatrick SJ, Safford KL, Pomeroy T, et al. Maternal hydration increases amniotic fluid index. Obstet Gynecol 1991; 78:1098.
  43. Kilpatrick SJ, Safford KL. Maternal hydration increases amniotic fluid index in women with normal amniotic fluid. Obstet Gynecol 1993; 81:49.
  44. Magann EF, Doherty DA, Chauhan SP, et al. Effect of maternal hydration on amniotic fluid volume. Obstet Gynecol 2003; 101:1261.
  45. Oosterhof H, Haak MC, Aarnoudse JG. Acute maternal rehydration increases the urine production rate in the near-term human fetus. Am J Obstet Gynecol 2000; 183:226.
  46. Powers DR, Brace RA. Fetal cardiovascular and fluid responses to maternal volume loading with lactated Ringer's or hypotonic solution. Am J Obstet Gynecol 1991; 165:1504.
  47. Tan KH, Smyth RM, Wei X. Fetal vibroacoustic stimulation for facilitation of tests of fetal wellbeing. Cochrane Database Syst Rev 2013; :CD002963.
  48. Caridi BJ, Bolnick JM, Fletcher BG, Rayburn WF. Effect of halogen light stimulation on nonstress testing. Am J Obstet Gynecol 2004; 190:1470.
  49. Bolnick JM, Garcia G, Fletcher BG, Rayburn WF. Cross-over trial of fetal heart rate response to halogen light and vibroacoustic stimulation. J Matern Fetal Neonatal Med 2006; 19:215.
  50. Rahimikian F, Rahiminia T, Modarres M, Mehran A. Comparison of halogen light and vibroacoustic stimulation on nonreactive fetal heart rate pattern. Iran J Nurs Midwifery Res 2013; 18:112.
  51. Braly P, Freeman RK. The significance of fetal heart rate reactivity with a positive oxytocin challenge test. Obstet Gynecol 1977; 50:689.
  52. Farahani G, Fenton AN. Fetal heart rate acceleration in relation to the oxytocin challenge test. Obstet Gynecol 1977; 49:163.