Intrauterine Growth Restriction (IUGR): Pathogenesis
Authors: Ricki Hagen Reviewers: Jaimie Bird Sarah McQuillan* * MD at time of publication
Abbreviations:
• DM: diabetes mellitus
• HTN: hypertension • IUGR: intrauterine growth restriction
• SGA: small for gestational age
• SLE: systemic lupus erythematosus
• TORCH: Toxoplasmosis, Others, Rubella, CMV, HSV
Maternal Factors
Maternal-Fetal Factors Placental malformations
(Ex. previa, accreta, infarction, abnormal implantation, ischemia)
Gestational HTN/ Preeclampsia
Multiple gestation Gestational DM
Fetal Factors Structural anomalies
(often comorbid with cytogenetic disorders)
Congenital infections
(Ex. TORCH)
Inborn errors of metabolism
Chromosomal disorders/ genetic syndromes
Multiple unclear intrinsic fetal mechanisms
Note:
Teratogenic medications (Ex. Warafin, Valproic Acid, Folic Acid Antagonists)
High altitude living
Smoking, ETOH and/or drug use
Malnutrition/ Low pre-gestational weight
Multiple unclear extrinsic fetal mechanisms
Medical conditions
(Ex: chronic HTN, cyanotic heart disease, severe chronic anemia, kidney disease)
Autoimmune conditions (Ex. Type 1 DM, SLE)
Decreased uteroplacental blood flow
Nutrient supply to fetus compromised
Reduction of total body mass, bone
mineral content, and muscle mass
Blood flow redirected away from vital organs to brain, placenta, heart and adrenal glands
Reduction of overall fetal size to increase survival
IUGR
Failure to reach genetically determined growth potential
• IUGR is not synonymous with SGA • Constitutional SGA is due to
paternal and maternal factors such as height, weight, ethnicity, and parity; it is not associated with increased risk for infant mortality or morbidity
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Published October, 30, 2018 on www.thecalgaryguide.com