How To Calculate Birth Weight
The calculation of estimated birth weight is done by plugging known factors into a computer system where a computer program works the equation and computes an estimate of the fetus' weight from 28 weeks until birth. The approximation of the birth weight is within 10 percent range, either more or less, of the actual birth weight and is more accurate for Caucasian mothers who are non-smokers, and when the mother and infant are in perfect health.
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Things You'll Need
- Ultrasound measurements of the fetus' arm, thigh, head and stomach
- Knowledge of fetus' gender, if applicable
- Approximation date of gestation
- Computer
- Internet connection
- Credit card, debit card or Paypal account
Instructions
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Ask your doctor if she can give you an estimate of your unborn child's birth weight. The doctor may make an estimate by feeling the infant through your abdomen or by taking measurements during an ultrasound. This may help the doctor determine the best birthing options, discover if the fetus is too large or too small and tell whether or not labor needs to be induced early.
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Have an ultrasound and record measurements of the thickness of the arm and thighbones, along with the circumferences of the fetus' torso, stomach and head. Because the extremities and body cannot be measure properly, an exact measurement cannot be given, so you'll get an estimation.
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Ask the ultrasound technician the sex of the fetus. This provides a more accurate estimation of the birth weight. Ask the ultrasound technician or physician to provide estimation of what week of pregnancy the expectant mother is in; bear in mind that in order for the estimation to be near accuracy the mother must be in the third trimester of pregnancy.
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Connect to the Internet with a computer or other Internet capable device and visit the PregnancyAndBaby.SheKnows website to access the birth weight calculator. Purchase the birth weight estimation calculation service via the Internet with a debit or credit card or a Pay Pal account; it will cost $14.95.
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Input the measurements and factors as the estimation calculator program prompts you. Input the gestation age of the fetus, the measurements taken in the ultrasound, and the fetus sex if known, and any other factors the program may ask you for.
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Check your email. You should receive your results with an estimate of your child's proposed weight at birth. You will be asked to later return an email with the infant's exact weight at birth, in order for program monitors to evaluate the effectiveness of the calculator.
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Tips & Warnings
The birth weight calculator described works only for single infant births.
