Why is “How much does the baby
weigh?” the first question asked of parents after delivery. Birth weight is the
only area where parents wish their children are average. This is because a
baby’s birth weight is a marker for its general health.
What is a Baby’s
A Baby’s Birth
Weight is the body weight of a baby at the time of
its birth. It is the only area where parents wish
that their children are average. A low birth weight, and parents worry that
their children are born ill; A high birth weight, and parents worry that their
children may be prone to obesity.
The first question that parents are asked upon the
birth of their child is “how much does the baby weigh?” This is because a
baby’s birth weight is a marker for its general health. It is no wonder then,
that from the moment your baby is born, doctors will closely monitor their
weight, height, head size and abdominal circumference. The average weight of a
baby born full term (i.e. between 37 and 41 weeks) is 3.2 kg. An average Indian
baby weighs approximately 2.8 kg. At full term, an average baby is 51 cm long
and will weigh anywhere between 2.7 to 4
Because a baby born either heavier or lighter than
the average weight may be prone to health problems, doctors may keep the
newborn under observation for a little while as a precaution.
What is a Low
Birth Weight Baby?
Organization terms any newborn weighing less than 2.5 kg as a Low Birth Weight
baby, irrespective of when the baby is delivered during the gestational cycle.
About 6 in 100 babies in the United Kingdom and 1 in every 12 babies in the
United States have a low birth weight.
Babies weighing less
than 2 kg at birth require special neonatal care for the first few weeks.
Babies born before
the 37th week of pregnancy have a low birth weight.
However, since the reason for the low birth weight is that they have been
delivered before finishing full term and development in the womb, they are
termed as Pre-Term babies and not Low Birth Weight babies.
How is the Weight of a Newborn
Babies are classified on the basis of
their weight at birth and their gestational age as shown
- High Birth Weight (HBW) – Birth Weight more than 4 kg
- Normal Birth Weight – Birth Weight around 3.2 kg
- Low Birth Weight (LBW) – Birth Weight less than 2.5 kg
- Very Low Birth Weight (VLBW) – Birth Weight less than 1.5 kg
- Extremely Low Birth Weight (ELBW) – Birth Weight less than 1 kg
- Small for Gestational Age (SGA) – Birth Weight less than the 10th Percentile
- Appropriate for Gestational Age (AGA) – Normal Birth Weight
- Large for Gestational Age (LGA) – Birth Weight greater than the 90th Percentile
- Intrauterine Growth Restriction (IUGR) – Lower Birth Weight compared to a baby's gestational age
Reasons for Differing Birth
The factors that determine why that some babies are
born with a lower birth weight as compared to other babies are as
A baby needs proper
nutrients to help it to develop properly in the womb. A mother’s poor diet
affects her baby’s weight and growth rate. Women are strongly advised to stay
away from Alcohol, Smoking and Illegal Drugs for the duration of their
The size of the parents affects the birth weight of
the baby. If the parents are either skinny or short, the baby will be born
smaller-than-average and vice-versa. If the mother puts on too much weight
during the pregnancy, the baby will have a higher-than-normal birth
A mother’s health
during pregnancy is one of the biggest determinants of the baby’s birth weight.
If the mother is anaemic or diabetic during pregnancy, or suffers from uterine
problems, it will affect the baby adversely. The blood supply to the placenta
may be reduced in case of a low-lying placenta, or high blood pressure in
pregnancy; which will decrease the amount of oxygen and nutrients reaching the
baby thereby restricting its growth and development. Rh incompatibilities,
infections such as toxoplasmosis, listeroids or sexually transmitted diseases
such as HIV-AIDS will also cause the baby to be born with a low birth
The mother’s own
birth weight and her genetic history will also affect the baby’s birth weight.
mother has a history of miscarriage, stillbirths, neonatal death or suffers from
pre-existing health problems like asthma and heart disease, then the baby is more
likely to be born with a low birth
Infections to the
baby during pregnancy and birth defects can affect your child’s birth weight
affecting the birth weight includes the Gender of the child. Boys are generally
born heavier than girls. Moreover, if the child is a Firstborn, he may be born
smaller than subsequent children. If the mother is carrying Twins or more; not
only are they born prematurely, but they also do not grow as much as single
babies owing to the lack of space. Race is also a factor. Caucasian babies have
a higher birth weight as compared to African-American, Asian, or Native American
What to Do if Your Baby Has a Low Birth
If you give birth to a low birth weight baby, the
doctors and nurses will anyways keep a keen eye on your baby to monitor its
health and development. However, there are some things that you are recommended
to do once you take your baby home:
- Ensure that your baby gets all its growth and development checks
- Pay attention to the baby’s weight. Any rapid weight gain or loss should be checked with your doctor.
- Ensure a nutritious diet for your baby. Use only those formulas recommended by doctors.
Influence of Low
Birth Weight on Adult Life
Most Low Birth
Weight Babies go on to lead healthy, normal lives. However, in some cases, it
can adversely affect the child’s adult life. Low birth weight is the main
causative factor for high infant mortality rates. The effects of low birth
weight depend on the cause of the low birth weight and the stage of pregnancy
in which the problem occurred.
Some of the severe
problems that could occur in the future are as
- Increased risk of infection
- Hypoglycaemia or low blood sugar
- Difficulty in keeping warm
- Polyglobulia or an increase in red blood cells leading to thickening of blood
Weight Loss and
Do not panic if your
baby loses weight after delivery. Newborn babies normally lose 5 to 10% of
their birth weight in a few days after delivery. This is because the baby loses
fluid after birth.
The baby will gain back all the weight after 10 to 14 days after
they start breastfeeding. If, however, the baby has lost weight because of a
sickness or premature birth, it will take up to 3 weeks to gain back the lost
Newborns gain about 30 g per day during the first
month and grow about 1 to 1.5 inches in height during the same period. Newborns
experience periods of rapid growth at 7 to 10 days and again at 3 and 6