In the past a baby would have been weighed in pounds and ounces.
When everything turned metric weights changed over to the new grams and kilograms.
A premature baby birth weight of say 2.2lbs or two pounds then became 1 kilogram for baby birth weights. Depending on the hospital you may hear a midwife say your premature baby's birth weight is 2 kilogram or they may still use the old method and tell you the figures in pounds and ounces.
Some staff find it strange changing over and even premature baby clothes are still made with the garment labels saying 3-5lb 5-8lb or nb which means newborn.
The earlier the premature baby gets delivered at the smaller the birth weight.
You may also come across terms such as low birth weight babies and its because as a baby is growing in the womb develops under 37 weeks gestation the chances are baby will deliver at a lower birth weight. Its because the middle trimester organs start to mature and baby increases in length before finally gaining weight during the last few weeks. Very premature babies tend to look very slender and resemble all arms and legs compared to a full term baby with more body fat laid down A baby born at 24 weeks can weigh as little as 1lb in weight or 500 grams.
I baby can stay and grow further along in pregnancy then baby will weigh more.#
On rare occasions if baby stops growing the chances are he or she will not weigh as much as the placenta which supplies valuable nutrients to baby can stop work and therefore growth is restricted.