returns the values for all properties of fetal development for the specified age of the fetus.


returns the value for a property of fetal development for the specified age.


returns the values for all properties of fetal development at the specified age and percentile.


returns the value for a property at the specified age and percentile.

Details and Options

  • The age of the fetus can be specified as a Quantity of time or as a future birth date using DateObject. It may also be given an Association of the form Association["Age"->age].
  • FetalGrowthData["Properties"] gives a list of all properties available for fetal development.
  • Indexed fetus properties include:
  • "AbdominalCircumference"circumference of abdomen
    "BiparietalDiameter"diameter of head between the two parietal eminences
    "CrownRumpLength"length from rump to top of the head
    "FemurLength"length of femur
    "HeadCircumference"maximum circumference of head
    "MeanAbdominalDiameter"average diameter of abdomen
    "OccipitalFrontalDiameter"diameter of head from the external occipital protuberance to the most prominent point of the frontal bone in the midline
    "ProjectedWeightBirth"projected weight at time of due date
    "Weight"estimated weight of fetus
  • Other properties include:
  • "AmnioticFluidIndex"interval range of typical amniotic fluid in the uterus
    "HeartRate"heart rate of fetus in beats per minute
    "Milestones"list of typical milestones for the current week of development
    "MilestonesNextWeek"milestones for the next week of development
    "MilestonesPreviousWeek"milestones for the previous week of development
    "TotalHeartbeats"total estimated heartbeats of the fetus
  • The percentile index can be used to obtain the values of a property for a specified percentile in the distribution of fetuses of a given age.
  • The percentile index can be either a percentage Quantity between 0 and 100 percent or a number between 0 and 1, both exclusive. It can also be specified as an Association with the key "Percentage" or "ZScore". "ZScore" allows the value at a specific z-score, or number of standard deviations, from the mean (at 0). Z-score should specified as a number between and .
  • If no index is specified for an indexed property, the interval within a standard deviation of the mean is returned.
  • When a property is not specified, values for all properties will be returned as an Association with the properties as keys.
  • FetalGrowthData takes the option UnitSystem, which determines the unit system in which to return Quantity objects. Its default setting is $UnitSystem.
  • FetalGrowthData is based on a wide range of sources, with enhancement at Wolfram Research by both human and algorithmic processing. Sources include but are not limited to Seeds and Cefalo (1986), Hadlock et al. (1985), and Moore and Cayle (1990).


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Basic Examples  (1)

Find the typical spectrum of weights in the fifth month of pregnancy:

Learn the typical milestones in the 30^(th) week:

Discover the value of the head circumference for the 90^(th) percentile at seven months:

Scope  (6)

Obtain a list of properties:

Use DateObject to specify due dates:

Obtain all properties at a specified age:

Find the 10^(th) percentile for all properties at seven months:

Find the value of femur length at the 10^(th) percentile in the fourth month of pregnancy:

Use the z-score index to find the circumference of the abdomen of a fetus two standard deviations up from the mean:

Options  (1)

UnitSystem  (1)

Control whether results are returned in metric or imperial units:

Applications  (2)

Explore how the number of weekly milestones varies over a pregnancy:

Discover that fetal heart rate slowly declines over a pregnancy:

Properties & Relations  (1)

Use FetalGrowthData to examine average head circumference prior to birth and HumanGrowthData for the following year:

Possible Issues  (3)

Not all properties are indexed:

Properties are only valid over a limited time range:

Index warnings and age range validation are suppressed when all properties are returned:

Introduced in 2015