The Ideal Weight Gain for a 3-Week-Old

As a new parent, you want to do everything you can to ensure your baby is healthy. When tracking your newborn's weight, you may notice patterns that concern you. Your baby soon after birth, before he leaves the hospital and usually within a few days of discharge, so you may notice his weight fall and rise during the first week or two of life. If you are worried that your baby is not gaining weight adequately, you can always take him to your pediatrician for a weight check for some peace of mind.

Normal Weight Gain

Most babies lose some weight immediately after birth. If you are formula feeding your baby, she may lose about 5 percent of her birth weight, and if you are breastfeeding, she may lose up to 10 percent of her birth weight. According to the American Pregnancy Association, babies typically gain between 5 and 7 ounces per week. By the time she is three weeks old, your baby should have started to surpass her birth weight.

Growth Spurts

Baby weigh scale.

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Many babies may begin a growth spurt at around three weeks of age. You may notice your baby wetting and soiling more diapers, and he may seem ravenous. This may be especially apparent if you are breastfeeding, and you might feel as though you are nursing constantly. The reason your baby needs to nurse more frequently is to build up your milk supply for his continually increasing growth. He may gain more weight now than he did during the first two weeks of his life, but soon his growth rate will go back to normal.

Slow Weight Gain

A baby's rate of growth can vary, depending how tall his parents are. As long as your baby is gaining weight steadily, being larger or smaller than average may be of no concern to her pediatrician. In some cases, very slow weight gain may be an indication of a health problem, such as pyloric stenosis or failure to thrive, so further testing or supplementation may be recommended if your baby is not gaining weight appropriately.

Signs of a Healthy Baby

Baby weigh scale.

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Attend each of your baby's recommended well-baby check-ups to keep track of his progress and weight gain. If you do not have access to an accurate baby scale, look for other signs that your infant is healthy and gaining weight. He should be wetting at least five or six diapers daily if he is eating enough. Breastfed babies usually have several bowel movements per day, and formula fed babies have fewer. Your baby should be alert in between eating and napping. If he is lethargic or not wetting enough diapers, call your pediatrician for advice.