بسم الله الّرحمن الّرحیم

Definition: fetus uniforfmly small for gestational age Etiologies of symmetric IUGR: Genetic disorders( e.x: trisomy 18,13,10 ) Fetal infections (e.x: cmv, para virus,Rubella) Congenital malformations Syndromes( e.x: AIDS embryopathy, Cornelia de lange )

Ultrasonographic findings in Symmetric IUGR 1-size less than expected for dates 2- structural survey more likely to be abnormal than with asymmetric IUGR ( aneuploidy ) 3- second trimester finding of echogenic bowel associated with IUGR in 10-20% cases. 4- usually a primary fetal abnormality,not placental insufficiency 5-DOPPLER is not as helpful as in asymmetric IUGR. 6- Does not exhibit “ head sparing “ flow in M.C.A. 1-size less than expected for dates 2- structural survey more likely to be abnormal than with asymmetric IUGR ( aneuploidy ) 3- second trimester finding of echogenic bowel associated with IUGR in 10-20% cases. 4- usually a primary fetal abnormality,not placental insufficiency 5-DOPPLER is not as helpful as in asymmetric IUGR. 6- Does not exhibit “ head sparing “ flow in M.C.A.

Imaging Recommendations 1- know accurate dating 2- early ultrasound is more accurate than LMP or clinical assessment of GA. 3- First trimester CRL measurments accurate to within +/- 0.7 weeks. 4- second trimester dating base on composite of several measurments ( BPD, HC,AC, FL ) 5- second trimester dating accurate to within +/- 1.5 weeks. 6-Third trimester dating accurate to within +/- 3-4 weeks. 7- Look at ossification centers, helps verify dating when patient present late in gestation. Distal femoral epiphysis > 32 w Proximal tibial epiphysis > 35 w

8- Evaluate amnotic fluid volume IUGR + polyhydramnios high risk for trisomy 18 Low fluid poor outcome 9- look at anomalies : Symmetric IUGR has strong associated with aneploidy Multiple anomalies + early onset IUGR triploidy,trisomy 13, Look at fetal hands : Clenched fingers trisomy 18 Postaxial ploydactyly trisomy 13 Syndactyly triploidy

Causes of UPI 1)Placental Disorders Chronic placental abruption Placenta previa Mosaicism ( e.x: localized placental trisomy 16 ) Marginal or Velamentous cord insertion Primary placental disorders Poor placentation

2) Maternal Etiologies A: Behavioral states Smoking Cocaine abuse B: Chronic medical condition Chronic lung disease (chronic obstructive pulmonary disease, Emphysema) Diabetes mellitus Chronic hypertension Collagen vascular disorders ( e.x: lupus ) Acquired thrombophilias ( e.x: Antiphospholipid antibody syndrome) Inherited thrombophilias ( e.x: Factor 5 leiden,prothrombin 20210A mutution)

Development of placenta 1)First trimester : A: Placental attachment B: Angiogenesis C: Cellular transport mechanism D: Onset of distribution & disposal of various substances between the maternal- fetal circulation by the onset of fetal cardiac activity.

2) The second trimester : A: Trophoblastic invasion in to the uterine B: Vascular remodeling C: Massive increase in total villous sureface area Capacity for maternal – fetal exchange Fetal cardiac output 3) The tird trimester : Establishment of fetal stress especially body fat because of fetus extra uterine existence

Doppler Velocimetry

Fetal Arterial Doppler 1)Umbilical Artery 2) Middle Cerebral Artery

(2) Middle cerebral artery MCA is the most accessible cerebral vessel in ultrasound imaging in the fetus. MCA carries 80% of cerebral flow. Cerebral circulation is a High-impedance circulation( reverse of Umbilical artery)

Brain Sparing Reflex ( fetal adaptation to oxygen deprivation) Fetal hypoxemia Increase blood flow to the brain,heart and adrenals Reduction in flow to the peripheral and placenta

Clinical applications of uterine artery Doppler In vitro fertilization o uterine receptiveness for implantation Risk assessment for maternal complications of pregnancy o PIH o Pre-eclamptic toxemia Risk assessment of poor fetal outcome o IUGR o SGA infant

Treatment Randomised controlled trials are currently in progress o Aim to see if abnormal uterine artery Doppler in early pregnancy can be effectively treated before onset of pregnancy complications Treatment options: o Aspirine o Vitamins E/C o Low molecular weight Heparine

Fetal venus Doppler Obtain from fetal central venus circulation Reflect the physiology status of the right ventricle. Inferior vena cava and ductus venosus are the most important

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