IUGR (Intrauterine Growth Restriction) 4th Year Medical Student PCM 34 Present 17th October ,2011
1 2 3 4 5 6 7 Definition Classification Cause Diagnosis Prevention Management Long term sequelae Contents
Failure of normal fetal growth
Most common definition
“ fetus weighing below 10th percentile for GA” (SGA)
BW < -2SD for GA
BW < 3rd percentile for GA
Classification Campbell and Thoms (1977) described the use of the sonographically determined head-to-abdomen circumference ratio (HC/AC) to differentiate growth-restricted fetuses. Symmetrical IUGR (type I) Asymetrical IUGR (type II) Combined type
Classification 1.Symmetrical growth restriction 20 % of IUGR Infants proportional decrease in all organs HC/AC ratio is normal Occurs inearly pregnancy : cellular hyperplasia Increase risk for long term neurodevelopmental dysfunction
An early insult could result in a relative decrease in cell number and size.
cellular maldevelopment with aneuploidy
It may cause a proportionate reduction of both head and body size.
Classification 2.Asymmetrical growth restriction 75 % of IUGR Infants Increase HC/AC ratio : decrease in abdominal size Brain sparing effects Occurs in late pregnancy : cellular hypertrophy Risk for perinatal hypoxia, neonatal hypoglycemia Good prognosis LOGO
Resultant diminished glucose transfer and hepatic storage would primarily affect cell size and not number, and fetal abdominal circumference which reflects liver size would be reduced.
Such somatic growth restriction is proposed to result from preferential shunting of oxygen and nutrients to the brain, which allows normal brain and head growth, so-called brain sparing.
The fetal brain is normally relatively large and the liver relatively small. Accordingly, the ratio of brain weight to liver weight during the last 12 weeks, usually about 3 to 1, may be increased to 5 to 1 or more in severely growth-restricted infants.
Classification 3. Combine type
More morbidities and mortalities More long term effects LOGO
Classification 3. Combine type
A fetus with asymmetrical IUGR might confront with cause of IUGR until cannot be compensated with brain sparing effect, may cause restriction of head circumference.
A fetus with symmetrical IUGR how have complication with circulation in late gestational aged, may cause reduction of abdominal circumference.
Cause Fetal causes Maternal causes Placental causes LOGO
Between 18 and 30 weeks, the uterine fundal height in centimeters coincides with weeks of gestation. If the measurement is more than 2 to 3 cm from the expected height or < 1oth percentile from normal curve, inappropriate fetal growth may be suspected
Diagnosis I. Clinical assessment
Uterine fundal height
Maternal body weight
: BW<45 kg or : BW increased < 6.5 kg all over pregnancy
characterized by absent or reversed end-diastolic flow
associated with fetal growth restriction
Normal velocimetry pattern with an S/D ratio of <30. The diastolic velocity approaching zero reflects increased placental vascular resistance. During diastole, arterial flow is reversed (negative S/D ratio), which is an ominous sign that may precede fetal demise
Stop and avoid all of the risk factors
Control maternal U/D
Correction of nutritional deficiencies
Low-dose aspirin prophylaxis
Prior IUGR history
Growth restriction near term
Recommend delivery at 34 weeks or beyond if there is clinically significant oligohydramnios
Growth restriction remote from term
No specific treatment
If diagnosed in prior to 34 weeks, and amnionic fluid volume and fetal surveillance are normal
“Observation is recommended± screening for toxoplasmosis,herpes,rubella,CMV and others” Specific treatment(causes of IUGR) and supportive care