Birth weight - very low, less than 1500 grams - 1500 grams is equivalent to less than 3 pounds, 5 ounces.

Birth weight - low, less than 2500 grams includes very low birth weight - 2500 grams is equivalent to less than 5 pounds, 8 ounces. Low birth weight may occur when an infant is born at less than 37 weeks of gestation, when intrauterine growth is compromised, or as a result of both conditions

Birth weight - normal, 2500 - 3999 grams - this range is equivalent to 5 pounds, 8 ounces to 8 pounds, 12 ounces.

Birth weight - high, 4000 grams or more - greater than 8 pounds, 12 ounces.

Birth weight WIC-low (500 - 2,500 grams inclusive) - In computing a rate the denominator excludes infants weighting less than 500 and greater than 5,999 grams or having unknown birth weight.

BIV Biologically Implausible Variable - data value beyond what is considered to be a biologically plausible range. BIVs are extremely rare and therefore considered to be an error.

BMI Body Mass Index - BMI is body mass index and is defined as weight in kilograms divided by height in meters squared (kg/m**2). All weights less than 22.6796 kg (50 pounds) or greater than 226.79185 kg (500 pounds) were assigned as unknown weight. All heights less than 101.6 cm (40 inches) or greater than 210.2612 cm (82.78 inches) were assigned as unknown height. These same categories are used for weight for the height BMI postpartum indicators.This measure is interpreted differently for children than for adults by taking into consideration age and gender. BMI is not an appropriate measure for children under the age of two.

Breast feeding - currently fully - at time of postpartum visit mother was exclusively feeding infant with breast milk.

Breast feeding - currently partially - at time of postpartum visit mother was feeding infant with breast milk and formula or other milk source.

Confidentiality Rule

Postpartum hematocrit(hct)/hemoglobin(hgb) - low, at postpartum adjusting for smoking and age less than 15 versus over 15
Below are the values used to define low levels.

Low Hematocrit
Low Hemoglobin
Age Non-smoker Smoker Non-smoker Smoker
Under age 15 18.0 - 35.6 18.0 - 36.6 6.0 - 11.7 6.0 - 12.0
Age 15 and older 18.0 - 35.6 18.0 - 36.6 6.0 - 11.9 6.0 - 12.2

(The above values are those used for WIC assessment during pregnancy.)

Prenatal hematocrit/hemoglobin low, adjusting for trimester blood was tested and smoking status
Below are the values used to define low levels.

Low Hematocrit
Low Hemoglobin
Trimester Non-smoker Smoker Non-smoker Smoker
First 18.0 - 33.0 18.0 - 34.0 6.0 - 11.0 6.0 - 11.3
Second 18.0 - 32.0 18.0 - 33.0 6.0 - 10.5 6.0 - 10.8
Third 18.0 - 34.0 18.0 - 35.0 6.0 - 11.5 6.0 - 11.8

(The above values are those used for WIC assessment during pregnancy.)

Other Cities/Counties (Joplin, Independence, Kansas City, and Eastern Jackson County)

Short stature for age is defined as less than the 5th percentile of the length-for-age of the 2000 NCHS/CDC growth chart for the United States. Short stature often reflects the long-term health and nutrition history of the child. In some children, short stature is related to factors such as low birth weight and short parental statures. Short stature may also be indicative of inadequate diet, delayed development, and /or compromised health.

Term pregnancy weight gain - adjusting for BMI and number born this pregnancy

Weight Gain (Pounds)
Prepregnancy weight Low Ideal High
BMI Underweight <=27 28 - 40 > 40
BMI Normal <=24 25 - 35 > 35
BMI Overweight <=14 15 - 25 > 25
BMI Obese <=14 15 - 25 > 25
Multi-fetal pregnancies <=34 35 - 45 > 45

Above except for obese weight gain is from Subcommittee on Nutritional Status and Weight Gain during Pregnancy and Subcommittee on Dietary Intake and Nutrient Supplement during Pregnancy, Food and Nutrition Board, National Academy of Sciences: Nutrition During Pregnancy, Parts I and II. Washington, D.C. National Academy Press. 1990.

The obese weight gain recommendation is from Krause's Food, Nutrition, and Diet Therapy by L. Kathleen Mahan and Sylvia Escot-Strump; 9th Edition (1996), pp. 183-184.

Below are the values used to define the different weight for length and age categories.

Categories for length and age:
Under weight (CDC) less than 10th percentile
Under weight less than or equal to the 10th percentile
Normal weight greater than 10th to less than 95th percentile
At risk of over weight 85th to less than 95th percentile
Over weight equal to or greater than 95th percentile
Biological implausible values z-scores less than -4 or greater than 5

Source for stature and weight for length indicators:
Kuczmarski RJ, Ogden CL, Guo SS et al. 2000 CDC growth charts for the United States: Methods and development. National Center for Health Statistics. Vital Stat 11 (246). 2002. The actual growth charts are available on the web at The SAS programs utilized to produce the percentiles and biological implausible values were acquired from CDC at:

Underweight is defined as a BMI of less than 19.8 and equates approximately with 90 percent of ideal body weight (IBW).

Overweight is defined as a BMI of 26.1 to 29.0 and equates to 121% to 135% IBW.

Obesity is defined as a BMI of 29.1 or greater, and equates to greater than 135% IBW.

*Although the 1998 National Heart, Lung and Blood Institute (NHLBI) Clinical Guidelines on the Identification, Evaluation and Treatment of Overweight and Obesity in Adults define adult obesity as equal to or greater than 30 BMI; the Institute of Medicine (1990) recommends using the pre-pregnancy weight classification that defines obese prenatal women as > 29.0 BMI, for postpartum, lactating and non-lactating women.

Weight for length/height for given age - The 2000 NCHS/CDC growth chart for the United States was also utilized to produce the cut-points and the biological implausible values for weight for length for age. Low weight-for-height or thinness (less than the 5th percentile) is often associated with a recent illness or chronic disease. A prevalence of low weight-for-height greater than five percent reflects serious health and nutrition problems. High weight-for height or overweight (greater than the 95th percentile) in the pediatric population is an important public health issue. One-third to one-half of those who are above the 95th percentile weight-for-height will become obese adults.