Intrauterine growth retardation
Synonyms and keywords: Intrauterine growth restriction

# Overview
Intrauterine growth retardation (IUGR) refers to poor growth of a baby while in the mother's womb during pregnancy.

# Classification
Asymmetrical IUGR is more common.  In asymmetrical IUGR, there is restriction of weight followed by length.  The head continues to grow at normal or near-normal rates (head sparing).  This is a protective mechanism that may have evolved to promote brain development.  This type of IUGR is most commonly caused by extrinsic factors that affect the fetus at later gestational ages.
Symmetrical IUGR is less common and is more worrisome.  This type of IUGR usually begins early in gestation.  Since most neurons are developed by the 18th week of gestation, the fetus with symmetrical IUGR is more likely to have permanent neurological sequela

# Pathophysiology
If the cause of IUGR is extrinsic to the fetus (maternal or uteroplacental), transfer of oxygen and nutrients to the fetus is decreased.  This causes a reduction in the fetus stores of glycogen and lipids.  This often leads to hypoglycemia at birth.  Polycythemia can occur secondary to increased erythropoietin production caused by the chronic hypoxemia.  Hypothermia, thrombocytopenia, leukopenia, hypocalcemia, and pulmonary hemorrhage are often results of IUGR.
If the cause of IUGR is intrinsic to the fetus, growth is restricted due to genetic factors or as a sequelae of infection.

# Causes

## Life Threatening Causes
- Alcohol abuse
- Cardiovascular disease
- Chronic hypertension
- Drug addiction
- Hypertension
- Kidney failure
- Lung disease
- Pulmonary disease
- Revesz syndrome
- Sickle-cell disease
- Syphilis
- Toxoplasmosis
- Tuberculosis

## Common Causes
- Abnormal cord insertion,
- Chronic abruption,
- Confined placental mosaicism,
- Conjoined twins,
- Cord anomalies,
- Fibrochondrogenesis,
- Gestational diabetes mellitus,
- Gestational hypertension,
- Maternal alcoholism,
- Maternal anemia,
- Maternal infection,
- Maternal kidney disease,
- Maternal kidney failure,
- Maternal lung disease,
- Maternal malnutrition,
- Maternal smoking,
- Mullerian dysgenesis,
- Multiple gestation,
- Multiple pregnancy,
- Neonatal haemochromatosis,
- Placenta abnormalities,
- Placenta previa,
- Placental insufficiency,
- Pre-eclampsia,
- Pregnancy-associated hypertension,
- Twin-to-twin transfusion syndrome,
- Uterine anomaly,
- Uterine malformations,
- Vertically transmitted infections,

## Causes by Organ system

## Causes by Alphabetical Order
- 3m syndrome
- Abnormal cord insertion
- Achondrogenesis
- Acitretin
- Alcohol abuse
- Alcoholism
- Anemia
- Arthrogryposis iugr thoracic dystrophy
- Aspartoacylase deficiency
- Atelosteogenesis type 1
- Atp6v0a2-related cutis laxa
- Autoimmune disease
- Beuren-williams syndrome
- Bloom's syndrome
- Bowen-conradi syndrome
- Bresheck syndrome
- Cardiovascular disease
- Celiac disease
- Chagas' disease
- Chromosomal abnormality
- Chromosome 13 trisomy syndrome
- Chromosome 18 trisomy syndrome
- Chronic abruption
- Chronic hypertension
- C-like syndrome
- Clotting disorders
- Codas syndrome
- Coffin-siris syndrome
- Confined placental mosaicism
- Congenital cytomegalovirus infection
- Congenital dyserythropoietic anaemia type 1
- Congenital hyperinsulinism
- Congenital rubella infection
- Congenital syphilis
- Congenital toxoplasma infection
- Conjoined twins
- Cord anomalies
- Cornelia de lange syndrome
- Cyanotic heart disease
- Cytomegalovirus
- De la chapelle dysplasia
- Diabetes mellitus, transient neonatal
- Donohue syndrome
- Down syndrome
- Drug addiction
- Eclampsia
- Ethanol
- Fetal akinesia-hypokinesia sequence
- Fetal trimethadione syndrome
- Fibrochondrogenesis
- Fryns syndrome 3
- Gestational diabetes mellitus
- Gestational hypertension
- Gracile bone dysplasia
- Gracile syndrome
- Haemoglobin bart's
- Hemoglobinopathies
- High altitude
- Humerospinal dysostosis
- Hutchinson-gilford progeria syndrome
- Hydrolethalus syndrome
- Hypertension
- Image syndrome
- Immunoneurologic disorder, x-linked
- Incontinentia pigmenti
- Japanese encephalitis
- Kidney disease
- Kidney failure
- Langer-saldino achondrogenesis
- Leprechaunism
- Lethal restrictive dermopathy
- Listeria monocytogenes
- Lowry-wood syndrome
- Lung disease
- Malnutrition
- Marden-walker syndrome
- Maternal alcoholism
- Maternal anemia
- Maternal collagen vascular disease
- Maternal infection
- Maternal kidney disease
- Maternal kidney failure
- Maternal lung disease
- Maternal malnutrition
- Maternal smoking
- Meckel-gruber syndrome
- Microcephaly
- Mullerian dysgenesis
- Multiple gestation
- Multiple pregnancy
- Neonatal haemochromatosis
- Neu-laxova syndrome
- Nicolaides-baraitser syndrome
- Osteogenesis imperfecta congenita
- Otopalatodigital syndrome type 2
- Pallister-hall syndrome
- Parvovirus b19
- Phenylketonuria
- Phenytoin
- Pitt-rogers-danks syndrome
- Placenta abnormalities
- Placenta previa
- Placental insufficiency
- Poor nutrition
- Pre-eclampsia
- Pregnancy-associated hypertension
- Primordial dwarfism
- Prolonged high-altitude exposure
- Protein-calorie malnutrition
- Pulmonary disease
- Pyelonephritis
- Rabson-mendenhall syndrome
- Revesz syndrome
- Rubella
- Russell-silver dwarfism
- Say-meyer syndrome
- Short syndrome
- Sickle-cell disease
- Smoking
- Spinal muscular atrophy with respiratory distress 1
- Substance abuse
- Syphilis
- Taybi-linder syndrome
- Tetra-amelia
- Thrombophilias
- Tobacco smoking
- Torch infection
- Toxin
- Toxoplasma
- Toxoplasmosis
- Trichohepatoenteric syndrome 1
- Tuberculosis
- Twin-to-twin transfusion syndrome
- Urinary tract infection
- Uterine anomaly
- Uterine malformations
- Vertically transmitted infections
- Virchow-seckel syndrome
- Williams syndrome
- Wolf-hirschhorn syndrome
- Yunis-varon syndrome
- Zinc deficiency

# Epidemiology and demographics
At least 60% of the 4 million neonatal deaths that occur worldwide every year are associated with low birth weight (LBW), caused by intrauterine growth restriction (IUGR), preterm delivery, and genetic/chromosomal abnormalities, demonstrating that under-nutrition is already a leading health problem at birth.

# Risk factors
Risk factors in the mother that may contribute to IUGR include:
- Alcohol abuse
- Clotting disorders
- Drug addiction
- High blood pressure or heart disease
- Kidney disease
- Poor nutrition
- Smoking

# Natural history, Complications and Prognosis
- After delivery, growth and development of the newborn depends on the severity and cause of IUGR.
- Depending on the specific cause, IUGR increases the risk for a variety of pregnancy and newborn complications.
- Infants may have a non-reassuring fetal heart rate during labor, requiring delivery by c-section.
- Perinatal mortality rates are 4-8 times higher for infants with IUGR, and morbidity is present in 50% of surviving infants.

# History and Symptoms
- A pregnant woman may feel that her baby is not as big as it should be.

# Physical Examination
- Uterine fundal height:  Smaller than expected for the baby's gestational age.