Intrauterine Growth Restriction IUGR

Normal Intrauterine Growth Stage 1 Stage 2 Stage 3 Hyperplasia Hyperplasia/ hypertrophy Hypertrophy 4-20 weeks 20-28 weeks 28-40 weeks Rapid mitosis Declining mitosis Rapid hypertrophy Increasing DNA content Increasing cell size Rapid increasing cell size rapid accumulation of fat, muscle, connective tissue Symmetric Mixed- asymmetric Asymmetric

Symmetric - Stage I growth inhibition Fewer cells but normal size - weight, head, length all < 10th percentile Perinatal problems? Higher Lower Growth potential?

Asymmetric - Stage II/III growth inhibition Decrease in cell size, less effect on total cell number - weight below 10th percentile,head and length preserved Perinatal problems? Higher Lower Growth potential?

What factors affect fetal weight? Sex term males 150 gm heavier and 0.9 cm longer than females Parity 1st born infants smaller effect loss after 3rd birth Race, ethnicity, nationality Altitude Denver population growth curves under estimate weights of infants born at sea level Maternal size maternal pre-pregnancy weight and pregnancy weight gain correlate with fetus size

“Maternal constraint”- non-genetic Number of fetuses Reduced rate of fetal growth of multiples Small breed embryo transplanted into large breed uterus will grow larger

Hormonal Factors Insulin Major hormone for in utero growth Produced by fetus Promotes fetal adipose deposition, glycogen stores

Etiology- Overlapping Maternal, Fetal, Placenta Maternal factors Medical disease (US) Malnutrition (world-wide) Multiple pregnancy Drugs Hypoxemia Small stature/ low pre-pregnancy weight Teen pregnancy Low SES Prima gravida Grand multiparity

Fetal Genetic Congenital malformations Genetic/ chromosomal (trisomies, syndromes) Cardiovascular disease Congenital infection Inborn errors of metabolism

Placenta placental insufficiency anatomic post dates abnormal insertion hemangiomas infarcts abruption

Diagnosis Algorithm IUGR TORCH stigmata  work-up? no yes TORCH stigmata  work-up? no Dysmorphic features  work-up?

Case # 3 Infant is delivered at 38 weeks to mom who presents with headaches and epigastric pain BW: 2.1 kg HC: 50th%tile Lt: 30th%tile Pre-eclampsia/ HELLP

Case # 3- What if? Mom with no prenatal care delivers undiagnosed twins at EGA 34 weeks Discordant twins

Case # 3- What if? An infant is delivered at 42 weeks via c- section due to NRHTs after induction Post dates - decreased subcutaneous fat - skin desquamation - wizened facies - large AF(diminished membranous bone formation) - meconium staining

Diagnosis Algorithm IUGR yes TORCH stigmata  work-up? no Dysmorphic features  work-up? Maternal/placental explanation work-up?

Case # 3- What if? Infant delivered at EGA 34 weeks to mom with no prenatal care and positive tox screen

Diagnosis Algorithm IUGR yes TORCH stigmata  work-up? no Dysmorphic features  work-up? Maternal/placental explanation work-up? Maternal drug use tox screen Unknown cause

True or False True IUGR infants are prone to asphyxia Why or why not? Perinatal hypoxia Chronic and acute Increased C/S rate, decreased Apgar, increased resuscitation need

An IUGR infant is at risk for Hypothermia? Hypoglycemia? Or Hypocalcemia? decreased subcutaneous fat, increased surface- volume ratio, decreased heat production decreased glycogen stores/ glycogenolysis/ gluconeogenesis increased metabolic rate deficient catecholamine release Associated with perinatal stress, asphyxia, prematurity

Which lab result(s) would not be associated with IUGR? WBC 4, S8 & B1 H & H 11/ 33 Plt 65 PT 16 PTT 56 Direct bilirubin 4.5 Neutropenia Polycythemia Elevated erythropoietin Thrombocytopenia Elevated coags TORCH

Which CxR is more consistent with IUGR? Increased meconium aspiration Decreased surfactant deficiency

Perinatal problems Perinatal asphyxia Hypothermia Hypoglycemia Hypocalcemia Polycythemia, hyperviscosity Thrombocytopenia Neutropenia Elevated coags Decreased surfactant deficiency Increased meconium aspiration syndrome Direct hyperbilirubinemia

Evaluation and Management Physical exam Labs - blood sugar - urine shell vial (CMV) - calcium - viral cultures (HSV) - CBC diff/plt - syphilis w/u - bilirubin - tox screen - head ultrasound - chromosomes - total IgM vs specific

Quick algorithm

Evaluation and Management Monitor postnatal weight gain/ head growth needs may exceed 100-120 cal/kg/d catch- up by 6-12 months Hypersomatotropism- accelerated growth velocity ? Safety of aggressive feeding rapid weight gain may predispose to childhood obesity highest risk for developing type 2 DM

IUGR- Outcome Neurodevelopment etiology and adverse event dependent lower intelligence, learning/ behavioral disorders, neurologic handicaps symmetric, chromosomal disorders, congenital infections--- poorer outcome school performance influenced by social class

World’s smallest…..