Biophysical Profile Calculator

Manning’s five components, each scored 2 if present and 0 if absent. The total runs 0 to 10 in even numbers only: an odd score is unreachable, and a page that offers one is not scoring this instrument.

Last updated 8 Oct 2026

Manning biophysical profile

5 items, 2 or 0 each, 0 to 10

Fetal heart rate reactivityLOINC codes reactivity as two or more accelerations within a 20-minute period; Manning’s own table reads two episodes of acceleration of 15 beats per minute lasting 15 seconds, associated with fetal movement, in 20 minutes. This is the LAST component to appear in development, at about 28 weeks, and the only one that is not sonographic. It is also the component the modified profile keeps.

Fetal breathing movementsAt least one episode lasting more than 30 seconds in 30 minutes of observation. Breathing movements are reliably seen on real-time ultrasound from about 20 weeks. Maternal fasting reduces them, which is a reason a score can fall without the fetus changing.

Gross body movementsAt least three discrete body or limb movements in 30 minutes, with continuous active movement counting as one. Note that one widely used reference states this criterion as fewer than two movements rather than fewer than three; LOINC and Manning’s own table both say three, and three is what this page uses. Movement develops at about 9 weeks.

Fetal toneAt least one episode of active extension with return to flexion of a limb or the trunk; opening and closing of the hand counts as normal tone. Scoring 0 means slow extension with return to partial flexion, a limb held in full extension, or absent movement. Tone is the FIRST component to appear, at about 7.5 to 8.5 weeks.

Amniotic fluid volumeLOINC codes this as at least one pocket measuring 2 cm in two perpendicular planes. Manning’s original 1980 table used 1 cm in two perpendicular planes and the threshold was later raised to 2 cm; the same chapter that prints the 1980 table prints the 2 cm figure in its footnote. This is the single deepest pocket, not the four-quadrant index.

8pointsExample

Non-reactive heart rate tracing; breathing, movement, tone and amniotic fluid volume all present

The five components, and why odd totals cannot happen

Total = reactivity + breathing + movement + tone + fluid, each 2 or 0
Range 0 to 10, in even numbers only: 0, 2, 4, 6, 8, 10 — six reachable scores, not eleven

2 or 0, never 1: each of the five components is scored present or absent. LOINC’s five biophysical profile terms all carry the same answer list, which has exactly two answers: Absent coded 0 and Present coded 2. There is nothing between them, so with five items there are 32 possible score combinations and only six possible totals
why that matters: a calculator that offers 0, 1 or 2 per component returns odd totals, and an odd biophysical profile score is not a score on Manning’s instrument at all. It is the most natural way to build this page wrongly, and the output looks entirely plausible
the components are not interchangeable: four are sonographic and one is a heart rate tracing. Amniotic fluid volume reflects a chronic process while the other four reflect central nervous system state at the moment of the scan, which is why the modified profile keeps the tracing and the fluid and drops the other three
the sequence of loss, and the disagreement about it: the gradual hypoxia model predicts that the activities appearing first embryologically are the last to disappear: reactivity lost first, then breathing, then movement, with tone last. Vintzileos and Ribbert found reactivity and breathing became abnormal first and movement and tone last; Manning did not find a clear sequential loss. Both findings are published
what it predicted, and where: ACOG’s figure is a false-negative rate of 0.8 per 1000 with a negative predictive value above 99.9% for stillbirth within a week; GLOWM’s table says 0.68 per 1000; Dayal and colleagues’ 86,955 patients gave 0.708 at one centre and 2.289 at the other. Cochrane’s five trials and 2,974 high-risk pregnancies found insufficient evidence for the test overall

Worked example

Non-reactive heart rate tracing; breathing, movement, tone and amniotic fluid volume all present
Reactivity 0, breathing 2, movement 2, tone 2, fluid 2
Total = 0 + 2 + 2 + 2 + 2 = 8 of 10
Score any one component 0 and the total is 8; score two and it is 6. Every step is two points, because there is no score of 1
All five present gives 10 and all five absent gives 0. The reachable totals are 0, 2, 4, 6, 8 and 10, which is why the band boundaries on the bar above sit at 5, 7 and 9 — scores no profile can take
A calculator returning 7 is not scoring this instrument

The five components and their criteria

Criteria as LOINC’s five biophysical profile terms print them, which agree with Manning’s table as reproduced in GLOWM apart from the fluid threshold: the 1980 table says 1 cm in two perpendicular planes and the current figure is 2 cm. The onset column is the reason the score is read with the gestational age.
Component	Scores 2 when	First appears at
Fetal heart rate reactivity	Two or more accelerations in a 20-minute period	About 28 weeks
Fetal breathing movements	At least one episode of more than 30 seconds in 30 minutes	Reliably from 20 weeks
Gross body movements	At least three discrete body or limb movements in 30 minutes	About 9 weeks
Fetal tone	At least one episode of active extension with return to flexion of a limb or the trunk	About 7.5 to 8.5 weeks
Amniotic fluid volume	At least one pocket measuring 2 cm in two perpendicular planes	Not a behaviour

What a normal score has predicted, and where the figures disagree

Three numbers for one quantity, and a threefold difference between two centres running the same test. Dayal and colleagues’ own recommendation was to report the ratio of false-negative fetal deaths to perinatal mortality rather than the false-negative rate alone, because the rate depends on the population tested.
Source	Figure	Cohort
ACOG antepartum surveillance guidance	False-negative rate 0.8 per 1000; negative predictive value above 99.9% for stillbirth within a week	Quoted as the basis for surveillance thresholds
GLOWM chapter 77, Table 9	0.68 per 1000	Attribution ambiguous in the chapter’s own text
Dayal and colleagues, 18-year series	0.708 per 1000 at one centre, 2.289 at the other	86,955 patients, 65 fetal deaths, two medical centres
Dayal and colleagues, cause	Fetomaternal haemorrhage was the most identifiable fetal cause of a false-negative result	Same series
Cochrane review of the biophysical profile	Insufficient evidence as a test of fetal well-being	Five trials, 2,974 high-risk pregnancies

Two or zero, and nothing in between

The biophysical profile is five observations, each scored 2 if present and 0 if absent. Four are sonographic — breathing movements, gross body movements, tone and amniotic fluid volume — and the fifth is a heart rate tracing. The total therefore runs from 0 to 10 and takes only even values: 0, 2, 4, 6, 8, 10. Six reachable scores out of an apparent eleven. LOINC’s five profile terms all carry the same answer list, with exactly two answers coded 0 and 2, which is as close to a formal statement of the point as the instrument has. The reason to labour it is that scoring each component 0, 1 or 2 is the natural way to build this page wrongly, and it produces odd totals that look entirely reasonable.

The components are not interchangeable, and the total hides that. Amniotic fluid volume reflects a process running over days to weeks; the other four reflect central nervous system state during the scan itself. The gradual hypoxia model predicts an order of loss from embryology — the activities that appear first, tone at seven to eight weeks and movement at nine, should be the last to go, with heart rate reactivity, which appears at about 28 weeks, going first. Vintzileos and Ribbert found that order. Manning did not. Both findings are in the literature and the page states both rather than preferring one. The same embryology is why a score is read with the gestational age: a fetus of 26 weeks has not developed reactivity, and GLOWM says plainly that age-related interpretation is necessary in very young fetuses.

What a normal score has predicted is where the honest reading gets uncomfortable. ACOG’s quoted false-negative rate is 0.8 per 1000 with a negative predictive value above 99.9%; GLOWM’s own table gives 0.68 per 1000; and Dayal and colleagues, following 86,955 patients over 18 years, found 0.708 per 1000 at one centre and 2.289 at the other, with fetomaternal haemorrhage the commonest identifiable cause. Cochrane’s review of five trials and 2,974 high-risk pregnancies concluded there was insufficient evidence for the profile as a test of fetal well-being at all. Against that background the modified profile — the tracing plus the fluid, and nothing else — reports a false-negative rate of the same 0.8 per 1000 in 1990s data, which is the argument for it. The fluid component is assessed by the single deepest pocket rather than the index, and the tracing is classified by the NICHD three-tier system separately. This page computes a number, or applies published criteria, and names the body that publishes them. It renders no clinical decision: nothing here says whether this fetus is compromised, whether a tracing should be acted on, whether a scan should be repeated, whether labour should be induced or when a pregnancy should be delivered. An obstetric measurement is read alongside the whole clinical picture – history, gestational age, serial trend, the other biometry – and never instead of it. It supports a clinician’s judgement rather than replacing it.

Frequently asked questions

Can a component score 1?

No. Each of the five scores 2 if present and 0 if absent, and LOINC’s five profile terms all carry the same two-answer answer list coded 0 and 2. The consequence is that the total is always even and only six totals are reachable: 0, 2, 4, 6, 8 and 10. A calculator that returns 7 is not scoring this instrument.

Which fluid threshold does the profile use?

The single deepest pocket, not the four-quadrant index. LOINC states the criterion as at least one pocket measuring 2 cm in two perpendicular planes. Manning’s original 1980 table used 1 cm in two perpendicular planes and the threshold was later raised. Scoring the component from an amniotic fluid index instead changes the instrument, and the two methods disagree systematically.

Does the gestational age change how a score is read?

Yes, and it has to. The components appear at different points in development: tone at about 7.5 to 8.5 weeks, movement at about 9, breathing reliably from 20, and heart rate reactivity at about 28. A fetus below about 28 weeks may be non-reactive because reactivity has not developed. GLOWM states that age-related interpretation is necessary in very young fetuses.

What is the false-negative rate?

There is no single number. ACOG’s guidance is quoted at 0.8 per 1000 with a negative predictive value above 99.9% for stillbirth within a week; GLOWM’s table gives 0.68 per 1000; and Dayal and colleagues found 0.708 per 1000 at one centre and 2.289 at another in the same 86,955-patient series. The rate depends on the population tested, which is why those authors recommended reporting it against the perinatal mortality of the population rather than alone.

Does a low score mean the fetus is hypoxic?

No. The components reflect central nervous system state at the time of testing and are affected by things that are not hypoxia: fetal sleep-wake cycles, which is why at least 30 minutes of observation is required before a variable is called absent, maternal fasting, which reduces breathing movements, and maternal medication. Cochrane’s review found insufficient evidence for the profile as a test of fetal well-being.

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References

Dahmus MA, Amon E. The Biophysical Profile. In: Global Library of Women’s Medicine, chapter 77. London: GLOWM.
Regenstrief Institute. LOINC 48770-2, Fetal Biophysical profile panel US, and member terms 11630-1, 11631-9, 11632-7, 11633-5 and 11635-0 with answer list LL531-5. Indianapolis: Regenstrief Institute.
Manning FA, Platt LD, Sipos L. Antepartum fetal evaluation: development of a fetal biophysical profile. Am J Obstet Gynecol. 1980;136(6):787-95.
Dayal AK, Manning FA, Berck DJ, et al. Fetal death after normal biophysical profile score: an eighteen-year experience. Am J Obstet Gynecol. 1999;181(5 Pt 1):1231-6.
The ObG Project. Antenatal Fetal Surveillance: Indications and Timing, citing ACOG Committee Opinion 828 and the ACOG Practice Bulletin on antepartum fetal surveillance.
Lalor JG, Fawole B, Alfirevic Z, Devane D. Biophysical profile for fetal assessment in high risk pregnancies. Cochrane Database Syst Rev. 2008;(1):CD000038, as cited in GLOWM chapter 77.

Not medical advice. For healthcare professionals and education. Reference intervals vary by laboratory and assay — always use your own laboratory's. Never base a dose or a treatment decision on this page alone. Full disclaimer at calcengines.com/disclaimer/