A newborn male, term, infant was born to a G2P2, Pacific Islander female by an uncomplicated pregnancy and vaginal delivery. Gestational age had been confirmed by a 21 week ultrasound. Because of increased fundal height measurements, the mother had been monitored by ultrasound in the third trimester and a birth weight of around 4300g had been expected. There was no gestational diabetes but the mother’s other child was large for gestational age (LGA).
The pertinent physical exam showed a large male with birth weight of 4430 grams (98%), head circumference of 37 cm (98%) and length of 53 cm (90%) and was symmetric. HEENT was normal. His clavicles were intact. There was no heart murmur. His spine was normal. The rest of his examination was normal.
The diagnosis of a LGA male was made, most likely due to genetic disposition. He was monitored by glucose protocol because of the risk of hypoglycemia but never needed intervention. His was breastfed and was discharged at 2 days with a 5% decrease in birth weight.
Infant size at birth is determined mainly by genetics, but also pregnancy and environmental factors. Large for gestational age (LGA) is defined as a mean weight > 2 standard deviations above the weight for gestational age or above the 90th percentile on growth charts (or ~4000 g on WHO growth charts). Macrosomia is a term used for a term infant who is > 4000g.
Risk factors for LGA infants includes:
- Male infant
- Genetic disposition
- Hispanic ethnicity
- Multiparity or grand parity
- History of previous LGA infant
Prenatal ultrasound is very helpful for antenatal management. First trimester fetal ultrasound is excellent for determining gestational age. Fetal abdominal circumference 1-2 weeks before anticipated delivery (before 40 weeks gestation) is also excellent at determining fetal weight. After 40 weeks gestation it is not accurate for determining fetal weight.
Similar to SGA infants having “catch-up” growth, LGA babies do show “catch-down” growth over time most of which is in the first 3 months of life especially for head circumference and length. However, LGA babies then show slower weight changes and long term consistently have higher BMI and subcutaneous fat. One study found, “The growth patterns of LGA preterm-born children are distinctly different from other preterm or full term children. In particular, we found substantially greater weight gains and relatively higher BMIs is among them, which added to their already increased metabolic risks based on their gestational age.”
For infants and children being LGA increases the risks for:
- Cognitive impairments
- Congenital malformations and genetic syndromes – a review of overgrowth syndromes can be found here
- Fetal death rates are higher in babies weighing > 4000 g in diabetic mothers, and > 4250g in non-diabetic mothers
- Electrolyte disorders – hypocalcemia, hypoglycemia
- Hematological problems – iron deficiency, polycythemia
- Infant of a diabetic mother risks, can be reviewed here
- Labor complications
- Prolonged labor
- Shoulder dystocia
- Brachial plexus injuries
- Clavicle or humerus fractures
- Meconium aspiration
- Obesity and overweight
- Persistent pulmonary hypertension
- Renal vein thrombosis
- Respiratory distress syndrome
For mothers includes:
- Increased Cesarean section deliveries
- Lacerations – perineal, vaginal, cervical
Questions for Further Discussion
1. What are common problems for an infant who is small for gestation age? A review can be found here
2. What monitoring and treatment must be done for infants who are LGA?
3. What defines grand parity vs multiparity?
- Disease: Large For Gestational Age Infant | Birth Weight
- Symptom/Presentation: Growth Problems
- Specialty: Neonatology
- Age: Newborn | Fetus and Mother
To Learn More
To view pediatric review articles on this topic from the past year check PubMed.
Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.
Information prescriptions for patients can be found at MedlinePlus for this topic: Birth Weight
To view current news articles on this topic check Google News.
To view images related to this topic check Google Images.
To view videos related to this topic check YouTube Videos.
Lawrence EJ. A matter of size: Part 2. Evaluating the large-for-gestational-age neonate. Adv Neonatal Care. 2007 Aug;7(4):187-97.
Taal HR, Vd Heijden AJ, Steegers EA, Hofman A, Jaddoe VW. Small and large size for gestational age at birth, infant growth, and childhood overweight. Obesity (Silver Spring). 2013 Jun;21(6):1261-8.
Bocca-Tjeertes IF, Kerstjens JM, Reijneveld SA, Veldman K, Bos AF, de Winter AF. Growth patterns of large for gestational age children up to age 4 years. Pediatrics. 2014 Mar;133(3):e643-9.
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa