When should Preemie double birth weight

"Most premature babies will catch up in size within the first year of life," says Mia Doron, associate professor of pediatrics at the University of North Carolina and coauthor of Preemies: The Essential Guide for Parents of Premature Babies.

At first, the doctor will measure your baby using a growth chart specifically for preemies. But once your baby's adjusted age is about 10 weeks, his doctor will switch to the conventional charts used for full-term babies. Many preemies move to a higher growth curve in a matter of months.

A small number of preemies never fully catch up and remain slightly smaller than average throughout their life. Sometimes there's a clear medical reason. For example, if your child had a hard time getting enough nutrition in his early months because of illness or postbirth complications, he's more likely to remain on a lower growth curve.

Very premature babies are also more likely to remain comparatively short, though they may catch up in terms of weight by their late teens.

There's often no obvious explanation why some preemies eventually match their peers in size and others don't. And if your child does turn out to be smaller than other kids his age, it's hard to know whether it's because of prematurity or plain old genetics.

In other words, there's no way to know what size your child should be catching up to. If people in your family or your partner's family tend to be short, your child may be short naturally.It's too early to tell whether a baby or young toddler will be tall or short. But by the time your baby is 2, his size can indicate how big he'll be throughout childhood and as an adult.

For example, if your child is in the 50th percentile for height and weight at 2, he'll probably stay pretty close to that throughout childhood. According to Doron, short 2-year-olds usually become short adults, and average-size 2-year-olds become average-size adults. Similarly, tall 2-year-olds often become tall adults.

But there are exceptions to every rule, and your child may jump out of his growth curve once he hits adolescence."Some research suggests that some preemies experience 'catch-up growth' during this time, but keep in mind that these are relatively small studies," says Doron.

One thing experts stress: Don't encourage a smaller baby or child to eat excessively try to help him catch up in size. Make sure your child gets adequate nutrition, and talk to his doctor about any feeding problems, which are common in premature babies. But forcing a child to eat more than he wants sets up unhealthy eating habits and could even contribute to health problems, like obesity, diabetes, and heart disease, later in life.

Instead, teach your child that size isn't everything. Your acceptance and encouragement – whether he's the tallest or the smallest in his class – will help him see that his stature is part of what makes him the unique and wonderful person that he is.

See our Child Height Predictor for a rough estimate of how tall your child will be as an adult.

Babies typically lose weight after birth, before they start to gain. A generally accepted rule of thumb is that a baby can be expected to lose about 3–7 percent of their birth weight during the first 5 days after birth. Parents should expect their baby to return to his or her birth weight by about day 10. 

Many babies double their birth weight by age 4 to 6 months and triple their birth weight by their first birthday. But babies who gain more slowly or more quickly may be perfectly healthy too. Your baby's doctor will monitor your baby's growth over time (weight, length, and head circumference) to ensure that they're getting all of the calories and nutrients they need. This is one reason why it's recommended babies have at least 6 doctor's visits during the first year.

Babies’ weight gain and loss doesn’t follow a pattern

It’s not clear how much weight exclusively breastfed babies lose and then gain in their first 14 days. A recent study of weight change in nearly 150,000 healthy babies found that it’s not uncommon for newborns to be below their birth weight even 21 days after delivery.

What are signs my baby is eating enough? 

Parents’ concern over weight is easy to understand given that it’s the only reliable indicator of growth. But if you know the signs that your baby is getting enough to eat, you don’t need an expensive in-home baby scale. A well-fed baby will… 

• be active and alert 
  
• be satisfied after breastfeeding 
  
• breastfeed at least 8–12 times during each 24-hour period 
  
• by day 3, have three or more poops a day
  
• by day 5, have yellow poop
  
• by day 5, have clear or pale yellow pee and six or more wet diapers a day
  

After 4 weeks of age, some babies continue to poop after every feeding, while others poop only once every other day, or once every 3–5 days. (Click here for more scoop on poop.) 

As long as you see these indicators of good health, there’s generally no reason to worry about having your baby’s weight measured between well-child visits.

What if my baby suddenly stops gaining weight? 

As long as your baby is reaching her developmental targets and isn’t losing weight, there’s no need to worry about a pause in weight gain. Children who fail to gain enough weight in the first 9 months will usually catch up over time. So parents seldom need to increase their child’s calories (by supplementing with donor milk or artificial infant formula). Consuming too many calories in infancy can actually lead to weight problems later in life. 

But if your baby loses more than 7 percent of their birth weight or gains weight slowly in the early days and weeks following their birth, your baby’s health care provider may ask you to bring them in for weight checks. A review of your breastfeeding routine and periodic weight checks will ensure that they're getting enough to eat and that there are no underlying health issues.

Does weight really matter? 

Weight is a measure of nutrition. When babies get too little food, too much food, or the wrong type of food, they can become malnourished. Today, experts agree that a brief period of underfeeding (days versus weeks or months) is unlikely to cause permanent damage. It can, however, have serious short-term consequences. Timing seems to be the key factor, since even a brief period of underfeeding in the first days after birth can lead to hyperbilirubinemia (jaundice) and hypoglycemia (low blood sugar). And if you’re concerned about your baby’s growth or feeding, contact their pediatrician.

Preterm or premature birth occurs when a woman delivers her baby before the 37th week of pregnancy. Various factors can cause preterm birth, but one of the most serious concerns is the babies’ low birth weight (LBW).

According to the American Academy of Pediatrics (AAP), “development is not a race, and babies develop at their own pace” (1). Therefore, even premature babies will gradually reach developmental milestones, including weight gain, if proper conditions are offered.

This post discusses premature babies’ weight gain and growth and provides a premature baby growth chart.

Understanding The Weight Of Premature Babies

The average weight of a newborn is seven pounds (3.17 kilograms). But the average weight of a preterm infant is about five pounds (2.26 kilograms) or less. The exact weight depends on how early the baby is delivered, with infants born after 28 weeks of pregnancy weighing 2.3 pounds (one kilogram) (2).

There is a difference in premature babies with low birth weight, compared to babies who suffered intra uterine growth retardation, so called “Small for gestational age” babies.

Weight, Height, And Head Circumference Growth In Premature Babies

The weight, height, and head circumference of a premature infant will vary depending on the gestational week of their birth and their overall health at birth. The following are some key points about the weight, height, and head circumference of premature babies:

Note that these are the average figures while the actual figures may differ from one baby to another.

• Premature infants are put in the neonatal intensive care unit (NICU) and ideally start gaining weight within a few days after birth.

• The weight gained can significantly differ among babies. A baby with a gestational age of 24 weeks (born after the 24th week of pregnancy) may attain five grams per day while those born at 33 weeks or later can put on as much as 30 grams per day (3).

• The desirable weight gain in babies who are born with a birth weight of more than two kilograms is 20-30 grams per day (4).

• The height of preterm babies increases by about 1.1 centimeters every week until the completion of the ideal gestational age, which is about 40 weeks.

• The chronological age of the baby is the absolute age, which is the time from the birth of a premature baby to the present. This age is also called postnatal age.

• A healthy premature infant is likely to show improvement first in the head circumference, followed by weight and height.

In the next section, we give you a detailed growth chart for premature infants.

Premature Baby Growth Chart

The Fenton growth chart for preterm infants is most commonly used for assessing the growth milestones of a premature baby. The Fenton chart was created in 2003 by Dr. Tannis Fenton, who revised it in 2013 to accommodate the new standards suggested by the World Health Organization (5).

In the next section, we list the approximate values for height, weight, and head circumferences for both preterm infant girls and boys. The value given is the 50th percentile, which is a median number (6).

Growth charts for premature infants

Weight, height, and head circumference of premature infant girls

Weight, height, and head circumference of premature infant boys

Source: Fenton Preterm Growth Chart Site, University of Calgary (7)

Not all babies develop the same way or at the same pace, as the growth at this stage depends on multiple factors. Doctors periodically assess a preterm baby in the NICU.

Note that the growth figures indicated by the doctor could be less or more than those mentioned in the chart. But as long as your doctor states that your baby is doing well, you can relax and look forward to taking your baby home from the NICU.

However, one thing you may still worry about is the baby’s nutrition as it can affect their weight significantly.

Nutrition For A Premature Baby

The doctors in the NICU will determine a premature baby’s feed after considering the gestational age and their overall health condition. Below are the sources of nourishment for a preterm infant:

1. Intravenous fluids: Early preterm babies will not be able to breastfeed and will require an intravenous delivery of nutrients and other fluids. The IV solution will be a mix of all the compounds that the baby will need to thrive and grow stronger.

1. Formula or breast milk through tube feeding: Once your baby’s digestive system is a bit strong, they can receive breast milk or formula directly into their stomach through a sterile tube that goes through their nose or mouth. This form of feeding is called nasogastric or orogastric tube feeding.

The doctor will determine the nature of the feed. If the mother is lactating sufficiently, then she can express breast milk, which would be then given to the baby through tube feeding. The quantity of breast milk or formula increases gradually in this method.

1. Breastfeeding: If your baby is a late preterm infant (born between 34-37 weeks), then they may be able to breastfeed. Both the mother and baby will require some initial practice. But once the baby understands to latch to the nipple, you can breastfeed the premature baby just like you would a full-term baby.

If the baby has trouble latching, then you can provide expressed breast milk through a feeding bottle. In the case of preterm delivery, breastmilk has more protein, minerals, and fat that the baby can easily digest (8). Breastmilk will also reduce the risk of intestinal infection.

1. Fortified formula: Breastmilk alone may not provide the nutrition that premature babies need to grow. They have a higher caloric requirement, usually around 120-kilocalories per kilogram of body weight per day (9). Fortified formula milk can provide the extra nutrition that preemies need, along with the right mix of vitamins and minerals for healthy growth. If required, the doctor may recommend this.

1. What is premature birth?

A birth that occurs before three weeks of the expected due date or before 37 weeks of gestation is called preterm birth. A baby born before 25 weeks of gestation is considered highly preterm, and before 32 weeks is very preterm (10).

2. Why does premature birth happen?

Premature birth may happen due to various reasons. Some can be induced or early cesarean section due to medical reasons. Multiple pregnancies, prenatal infections, and chronic conditions such as hypertension and diabetes can result in premature birth. However, there can be cases of premature birth with no apparent causes (11).

3. What factors increase the chances of premature birth?

A positive personal or family history of preterm birth can increase the chances of preterm birth. There are also increased chances in women under age 20 or above 40 and among African Americans. Being underweight and smoking during pregnancy can also increase the risk (10).

4. How does premature birth affect a child’s development?

Preterm birth is the leading cause of mortality in children under age five in most countries. While some preemies may thrive and grow as term infants without significant problems, a few might face disabilities (11).

5. How can premature birth be prevented?

There is no sure way to prevent premature birth. Eating healthy, reducing stress, and taking adequate prenatal care may reduce the risk. A minimum of an 18-month gap between subsequent pregnancies is also recommended to reduce the chance of preterm delivery. Avoiding alcohol, tobacco, and other drugs may also reduce the risk of premature birth in some cases (10).

You may give premature birth to your baby if they’re born before 37 weeks of gestation. Your baby could be in the low birth weight index if born prematurely. Also, some babies may need NICU to facilitate their proper growth and improve survival rates. Though it may be disheartening to see your newborn in an incubator, it is essential for their growth. This phase is temporary, and your baby will eventually gain weight with appropriate nourishment and care. As your baby initiates feeding well, has normal body functioning, and develops at the right pace, you may take them home.

References:

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Dr. Elna Gibson is a general pediatrician. She did her MBChB and specialization as a pediatrician in South Africa at the University of Pretoria. She obtained MMed Pediatrics (masters) with distinction in 1993. As a young specialist, Dr. Gibson spent some time in the Netherlands, and then settled in the Vaal Triangle where she has practiced for 25 years. She... more