OVERVIEW

What is a large for gestational age infant?

A large for gestational age (LGA) infant refers to a newborn whose birth weight exceeds the 90th percentile for their gestational age.

This means the newborn's birth weight is greater than 90% of other infants born at the same gestational age. In other words, the baby is among the top 10% heaviest newborns for that gestational age.

A high birth weight is not usually a special concern and often requires no additional treatment. However, some LGA infants may develop complications that can harm both the baby and the mother, potentially necessitating medical intervention.

Is large for gestational age common?

Yes. Approximately 9% to 10% of newborns are classified as large for gestational age.

SYMPTOMS

What are the manifestations of large for gestational age infants?

The most obvious manifestation is the infant's large body weight and excessive subcutaneous fat.

It may be accompanied by symptoms such as rapid breathing after birth, cyanosis, refusal to feed, pallor, lack of crying or fussing, and asymmetrical hand movements, which often indicate complications.

What other problems might large for gestational age infants cause?

Full-term large for gestational age infants may have a birth weight exceeding 4,000 g, meeting the criteria for "macrosomia."

• For the mother, a large infant can lead to dystocia, increasing the risks of cesarean section, postpartum hemorrhage, and vaginal tearing.

• For the infant, excessive weight may result in complications such as neonatal asphyxia, clavicle fracture, brachial plexus injury, cephalohematoma, or meconium aspiration at birth. After birth, issues like hypoglycemia may also occur.

Do large for gestational age infants have long-term sequelae?

Large for gestational age infants themselves do not have sequelae, but severe complications may lead to long-term effects.

CAUSES

What are the causes of large for gestational age infants?

• High maternal blood sugar during pregnancy, such as gestational diabetes, is a common cause of excessive fetal weight.

• Unhealthy maternal diet during pregnancy, excessive nutritional supplementation leading to maternal obesity and excessive weight gain, may also result in a large fetus.

• Genetic factors: If parents have large body sizes, the child may also be large, increasing the likelihood of a large for gestational age infant.

• Male infants are more likely to be large for gestational age than female infants.

• Infants with a gestational age exceeding 42 weeks are more prone to being large for gestational age.

• Certain rare congenital developmental disorders may also cause large for gestational age infants, such as islet cell hyperplasia, Beckwith-Wiedemann syndrome, Sotos syndrome, Weaver syndrome, Berardinelli lipodystrophy syndrome, and Simpson-Golabi-Behmel syndrome.

DIAGNOSIS

How is large for gestational age diagnosed?

During pregnancy, fetal weight can be estimated through color ultrasound and compared with gestational age to preliminarily determine if the fetus is large for gestational age.

After birth, the child's birth weight and gestational age can be compared with statistical data tables to diagnose whether the infant is large for gestational age.

What tests are needed if complications are suspected in a large-for-gestational-age infant?

Depending on the child's symptoms, tests such as blood glucose measurement, physical examination, chest X-ray, blood gas analysis, electromyography (EMG), and cranial magnetic resonance imaging (MRI) may be required.

• Blood glucose monitoring: Since large-for-gestational-age infants are prone to neonatal hypoglycemia, blood glucose levels need to be monitored.

• Physical examination: To assess whether the child has complications such as clavicle fractures, brachial plexus injuries, or cephalohematoma.

• Chest X-ray: Can reveal clavicle fractures. If the child exhibits rapid breathing, it can help determine whether there is meconium aspiration or respiratory distress syndrome.

• Blood gas analysis: If the child shows cyanosis, this test can identify hypoxia or acidosis.

• Electromyography (EMG): Can assess the extent of brachial plexus injury.

• Cranial MRI: If asphyxia occurs, cranial MRI can help evaluate brain damage.

What should parents pay attention to when a large-for-gestational-age infant undergoes these tests?

Cranial MRI and electromyography may require the child to take oral sedatives. Under medical supervision, oral sedatives are very safe, and the currently used sedatives are quickly eliminated from the child's body. Parents should not delay necessary examinations or treatments due to excessive concern about the side effects of sedatives.

TREATMENT

Can large for gestational age babies be delivered vaginally?

Vaginal delivery can still be attempted for large for gestational age babies, and a cesarean section is not always necessary.

Of course, the doctor will comprehensively evaluate factors such as the baby's weight, the mother's birth canal conditions, and the overall condition of both mother and fetus before labor to decide whether to attempt a vaginal delivery.

Which department should large for gestational age babies see?

If complications occur, they should be treated in the neonatology department or neonatal intensive care unit (NICU).

How are large for gestational age babies treated?

Large for gestational age babies who have a smooth birth process and show no symptoms after birth do not require hospitalization in the neonatology department or NICU. After blood glucose monitoring, they can stay with their mother in a rooming-in arrangement.

If symptoms such as asymmetrical hand movements, inability to lift or grasp with the hands, palpable lumps on the collarbone or head, refusal to feed, or pale complexion are observed, prompt assistance from a pediatrician should be sought to assess for complications. Severe complications may require hospitalization.

If the baby experiences asphyxia or hypoxia at birth, hospitalization in the neonatology department or NICU should be arranged as advised by the doctor.

What should be noted during hospitalization for large for gestational age babies?

During rooming-in hospitalization in the obstetrics department, ensure timely on-demand feeding to prevent hypoglycemia. Monitor the baby for noticeable yellowing of the skin or whites of the eyes to detect jaundice early.

For vaginally delivered babies, pay attention to whether hand movements are symmetrical to promptly identify collarbone fractures or brachial plexus injuries.

If the baby is admitted to a non-accompanied neonatal ward due to complications, family members should encourage the mother to pump breast milk regularly (which can be stored in breast milk storage bags and refrigerated) to maintain sufficient lactation. This ensures the baby can still receive breast milk after discharge, which is highly beneficial for long-term health.

If permitted by the neonatal ward, the pumped breast milk can also be provided to the baby during hospitalization to allow for breastfeeding.

DIET & LIFESTYLE

What should large-for-gestational-age infants pay attention to in their diet?

Breastfeeding is encouraged, with early initiation and frequent suckling. This can meet the baby's nutritional needs, prevent hypoglycemia, and promote milk production.

What should large-for-gestational-age infants pay attention to in daily life?

Ensure adequate feeding, start breastfeeding as early as possible, and feed on demand.

Due to their larger size, large-for-gestational-age infants require more milk than other babies. If the baby becomes fussy or cries within an hour after feeding, frequent feeding can ensure sufficient nutrition and prevent hypoglycemia caused by inadequate intake.

PREVENTION

How to Prevent Large for Gestational Age Babies?

• Mothers should maintain a balanced diet during pregnancy, consuming appropriate amounts of staple foods, meat, eggs, dairy, vegetables, and fruits. However, they should avoid high-fat diets, excessive intake of rich foods, and rapid weight gain.

• Regular prenatal checkups during pregnancy can detect trends of fetal weight exceeding gestational age through ultrasound, allowing for early intervention.

• If the mother has high blood sugar or rapid weight gain during pregnancy, she should focus on proper dietary control, moderate exercise, and insulin therapy if necessary to prevent large for gestational age babies.

• If the baby is too large and causes delivery difficulties, follow the doctor's advice to choose a delivery method that benefits both mother and child, reducing the risk of dystocia.

Are Mothers of Large for Gestational Age Babies More Likely to Have Another Large Baby in Future Pregnancies?

Mothers who have previously delivered a large for gestational age baby may have a higher chance of having another one. During pregnancy, they should focus on dietary control, blood sugar monitoring, and avoiding rapid weight gain.