Birth Weight and Your Baby

Babies change so fast. In the first year of life, a baby will triple her birth weight, increase her length by 50%, begin to grow teeth, learn to crawl then walk and maybe even say her first words. Since she changes so much in such a short amount of time, how important is her birth weight?

What is a Normal Birth Weight?
Most full-term newborns (born at between 37 and 40 weeks) will weigh between 6 lbs, 2 oz (2,812 grams) and 9 lbs, 2 oz (4,173 grams), and be anywhere from 19 to 21 inches long (48 to 53 cm).

Most babies will lose a small amount of weight soon after birth. This is due to excess fluid at birth, and isn�t a cause for concern. If, however, your baby loses too much weight, that might be an indicator of a health problem and she will need to be monitored by a doctor.

Weight and size gain is a very good indicator of health in newborns. Your baby�s weight and size will be carefully monitored in the first few months of life. A baby who is growing well is considered to be generally healthy, while poor growth can be a sign of problems.


Low Birth Weight?

Babies who are born weighing less than 3 lbs, 4 oz (1,500 g) are considered very low birth weight. Only about 1.5% of babies are born this small. These babies will appear very thin, and their skin will likely be very pale or translucent.

Who is Affected by Very Low Birth Weight?
Babies who are premature at birth and babies of multiple births are the most likely to be tiny � about 33% of triplets and 10% of twins are likely to have low birth weight. Other factors that may cause low birth weight are:


  • Age: Young women, especially those under the age of 15, are at a greater risk of giving birth to low birth weight babies.
  • Mother�s Health: Women who have smoked, taken drugs or consumed alcohol are more likely to have low birth weight babies. Women who have poor nutrition, or inadequate prenatal care, often due to socio-economic status, and complicated pregnancies, are all more likely to produce babies of low birth weight.
  • Race: In the United States, African-American women are twice as likely as Caucasian women to give birth to a tiny baby.


Common Problems for Low Birth Weight Babies


  • Difficulty feeding and gaining weight
  • Infection
  • Low oxygen levels at birth
  • Inability to maintain body temperature
  • Sudden infant death syndrome (SIDS)
  • Neurological problems, i.e. intraventricular hemorrhage (bleeding inside the brain)
  • Gastrointestinal problems, i.e. necrotizing enterocolitis (NEC), a serious disease of the intestine common in babies born prematurely.
  • Problem with breathing, i.e. respiratory distress syndrome (a respiratory disease of caused by immature lungs)


Long-term complications for low birth weight babies include:


  • Blindness
  • Deafness
  • Cerebral palsy
  • Mental retardation

The lower the birth weight, the greater the chances are that the child will eventually develop neurological and intellectual problems.


High Birth Weight and Large for Gestational Age

A baby born weighing 8 lbs, 14.8 oz is considered high birth weight, also called macrosomia. Since this falls within the normal range, it is not usually a cause for concern. More troublesome are babies born large for gestational age (LGA). Full-term male babies weighing more than 9 lbs, 3 oz (4,200 g) and females weighing more than 8 lbs, 9 oz (4,034 g) are considered LGA.

Causes of Large for Gestational Age
Genetics can play a part in LGA births. Some babies will be large simply because their parents are large. The amount of weight gained by the mother during pregnancy can also play a part in birth weight, especially if the amount gained is considered excessive. Maternal diabetes (pre-existing or gestational diabetes) is the most common cause of LGA. Increased blood sugar in the mother will cause the baby�s body to produce extra insulin, which can lead to fat deposits and excessive growth.

Common Problems for LGA babies
Delivery problems due to the larger size of LGA infants is the most common problem. Delivery problems can include:


  • Difficult birth
  • Prolonged vaginal delivery time
  • Increase in cesarean delivery


When a diabetic mother is the cause of LGA, the baby will likely have problems regulating their own blood glucose. This can result in the following problems:

  • Increased incidence of birth defects
  • Respiratory distress/difficulty breathing
  • Hypoglycemia (low blood sugar)
  • Hyperbilirubinemia/jaundice - yellowing of the skin, mucous membranes and eyes


Remember that it is important to monitor the weight of all newborns to ensure that they�re healthy and growing normally. Birth weight is not necessarily an indicator of what size a baby will be once she reaches maturity. Many low and high birth weight babies grow up to be perfectly healthy, normal sized adults.


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i gave birth to a big baby boy quite a long time ago he weighed 9lbs 3oz he has a friend who weighed over 10lbs at birth!
13 years ago
I just gave birth to a (surprise) 10lb girl vaginally (in the water) with no tears or meds. It can be done. I was surprised.We have no idea whyshe was so big my husband and I are 5'6"and I only gained 28 lbs! My 12 year old was under 7 lbs! I hadno sweet tooth or much of an appetite during my pregnacy. Try to up your protein, greek yogurt, nuts,an beans saved me these past 9months. And NO sugary drinks...water and milk only!!!
13 years ago
i have gestational diabetes and they say my baby is measuring larger than he should for his age. my doctor told me i have to get my blood sugar under control and if i don\'t he is going to put me on insulin. i have to start testing my blood sugar every day. if i don\'t get the blood sugar under control my baby could grow to big and this can be dangerous. and i might need a c-section because the baby will be too big to birth normally. i am seeing a nutritionist tomorrow to find out how i should start eating. wish me luck!
13 years ago