The average baby born in the U.S. weighs around eight pounds. Low birthweight- less than five pounds, eight ounces- occurs in approximately eight percent of births and the number continues to rise.
Risk Factors for Low Birthweight Babies
The majority of the time, low birthweight is the result of premature birth- when babies are born prior to 37 weeks. During the last few weeks of pregnancy, your baby will gain most of his or her weight so that early birth can result in a smaller than average baby.
Premature birth and low birthweight are common when carrying multiples. In fact, half of multiples will be born weighing less than five pounds, eight ounces. In addition, several maternal factors can increase your likelihood of having a baby with low birthweight. Mothers who are African-American, teenaged (especially under 15 years old), malnourished or users of drugs, alcohol or cigarettes during pregnancy have a higher prevalence of low birthweight babies.
Your obstetrician will monitor you and your baby closely if you fall into any of these high-risk categories.
Intrauterine Growth Restriction (IUGR)
A baby may be carried to full term and still have low birth weight if there is intrauterine growth restriction (IUGR). With IUGR, your baby may be fully mature but weak and underweight. Intrauterine growth restriction is generally caused by a problem with the placenta, mother’s health or the baby’s condition. IUGR can be identified by your obstetrician during regular check-ups throughout your pregnancy.
Complications from Low Birthweight
Low birthweight babies almost always require a stay in the Neonatal Intensive Care Unit (NICU). At birth, these small babies often have low oxygen levels, difficulty feeding and gaining weight, greater risk of infection and trouble maintaining their body temperature. Since low birthweight usually coincides with premature birth, it can be difficult to separate low birthweight issues from those caused by premature birth. Premature babies may suffer from breathing, neurologic and gastrointestinal problems.
Diagnosing Low Birthweight
During pregnancy, your obstetrician can diagnose low birthweight by measuring the height of the fundus, or the top of a mother’s uterus, from the pelvic bone. The size usually corresponds to the number of weeks. Ultrasound can also be used to more accurately estimate fetal size by measuring the head, abdomen, and femur to compare to a fetal weight chart.
At birth, your baby will be weighed. If your baby is below five pounds, eight ounces, he or she is considered to have low birth weight. Babies weighing less than three pounds, five ounces have very low birthweight.
Pre-natal care is an important key to preventing preterm birth and monitoring for low birthweight. Call our office to schedule a pre-natal visit with your obstetrician and discuss the likelihood of low birthweight.