Breastfeeding: Test Weighing Your Baby

What is test weighing a baby?

Sometimes your baby's doctor needs to know how much your baby is feeding. Test weighing is used to measure how much breast milk your baby drinks from your breast during a feeding. This helps make sure your baby is getting enough milk to grow and develop. Test weighing babies is usually done in the hospital. Not all babies need to be test weighed.

A baby should gain a little weight during a feeding because he or she has taken some milk. The baby is weighed twice: right before and right after a feeding, with the clothes on. The first, lower weight is subtracted from the second, higher weight. The difference between these two weights is the amount of milk the baby drank. One gram of weight is equal to one millilitre (ml) or one cubic centimetre (cc) of milk.

How to test weigh your baby

For test weighing to be correct, you need a digital electronic infant weight scale that shows weight in grams; for example, the Medela BabyWeigh TM scale. A scale that shows weight in kilograms or pounds is not precise enough.

Caution: Never leave your baby alone on the scale as a fall can seriously injure your baby.

Dress your baby in the clothes, blankets, hat, or bib that he or she will be wearing during the feeding. Do not change the diaper or any clothes until after you have weighed your baby the second time after the feeding.

When using a Medela BabyWeigh TM scale

  1. Bring the electronic scale to your baby’s bedside. Make sure the scale is on a flat surface. Place a towel or blanket in the scale tray.
  2. Press the On/Zero button and wait until '0' is displayed digitally.
  3. Place your baby on the flat surface of the scale tray.
  4. Hold one hand above your baby as you wait for the scale to lock in the weight and record the final weight. You will hear a 'beep' sound and see an arrow beside the baby's weight.
  5. Push 'Weight Entry'. This saves the baby's weight before breastfeeding, in the scale memory. You may also wish to write down the baby's weight. This is the 'pre-feeding' weight.
  6. Remove your baby from the scale and breastfeed as you normally would.
  7. Press the On/Zero button and wait until '0' is displayed digitally. Put your baby back on the scale after breastfeeding and reweigh. The clothes your baby is wearing and the blanket on the tray should all be the same for this second weighing.
  8. Again, hold one hand above your baby as you wait for the scale to beep and the arrow to appear besides the final weight.
  9. Push 'Weight Gain' and the scale tells you the amount of breastmilk your baby drank at the breast.
  10. You may also want to write down the baby's weight after the breastfeeding. Mark this as the 'post feeding weight'. Subtract the 'pre-feeding weight' from the 'post-feeding weight'. The result is the amount of milk your baby drank.

When using other electronic scales

  1. Bring the electronic scale to your baby’s bedside. Make sure the scale is on a flat surface. Plug in the scale if it is not a battery scale. Place a towel or blanket in the scale tray.
  2. Press the On/Zero button and wait until '0000' is displayed digitally. Check that the scale is set to show the weight in grams.
  3. Place your baby on the flat surface of the scale tray.
  4. Hold one hand above your baby as you wait for the scale to lock in the weight and show the final weight. Many scales make a 'beep' sound when it has locked into the baby's weight.
  5. Write down the baby's weight in grams. This is the 'pre-feeding' weight.
  6. Remove your baby from the scale and breastfeed as you normally would.
  7. Press the On/Zero button and wait until '0000' is displayed digitally. Put your baby back on the scale after breastfeeding and reweigh. The clothes your baby is wearing, the blanket on the tray, should all be the same for this second weighing.
  8. Again, hold one hand above your baby as you wait for the scale number display to stop changing and lock into the baby's weight.
  9. Write down the baby's weight in grams. This is the 'post-feeding' weight.
  10. Subtract the 'pre-feeding weight' from the 'post-feeding weight'. The result is the amount of milk your baby drank.

An example of the pre and post weight calculation:

Your baby’s pre-feeding weight is 3010 grams and the post-feeding weight is 3040 grams. The change in the baby’s weight is 30 grams. Because grams and ml (or cc) are equal, your baby drank 30 ml or cc of milk.

If your baby is in hospital

Babies in hospital can have many tubes as well as wires to monitor them. This can make it difficult to get accurate weights. Check with your nurse if monitoring wires can be removed just before weighing.  Make a bundle of the rest of the tubes and hold in the same place for both the pre- and post-weighings. Have the scale in the same place as well.

Getting enough milk

Your baby's doctor, nurse, or dietitian will know how much milk your baby needs. The amount will depend on your baby’s size, age, and medical condition.

If your baby has taken enough milk at the breast and appears satisfied, the feeding session is complete.

If your baby has not taken enough milk from the breast, you should give a feeding supplement to finish the feed. Your baby's nurse will help you decide how much extra feeding to give your baby.

For more information, please see "Breastfeeding: Making Sure Your Baby is Getting Enough Milk."

Key points

  • Test weighing is a way to find out how much milk your baby drank from the breast during a feeding.
  • To test weigh your baby, weigh him or her right before and right after a feeding, using an electronic scale that displays weights in grams. The difference in weight is the amount your baby drank during the feeding.
  • If your baby is not receiving enough milk during a feeding, a supplement will be given to your baby so that he or she receives a proper amount of nutrition.

Debbie Stone, RN, IBCLC, RLC

Joyce Touw, BScN, PNC(C), RN, IBCLC, RLC

11/6/2009
 




Notes: