iugr boom&fnd latest
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4th Year Medical Student PCM 34
Present 17th October ,2011
IUGR(Intrauterine Growth Restriction)
Contents
Definition1
Classification2
Cause3
Diagnosis4
Prevention5
Management6
Long term sequelae7
Definition
Failure of normal fetal growth Most common definition
“ fetus weighing below 10th percentile for GA”(SGA)
Other definition BW < -2SD for GA BW < 3rd percentile for GA
10th Percentile
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 in early pregnancy : cellular hyperplasia
Increase risk for long term neurodevelopmental dysfunction
LOGO
Classification
1. Symmetrical growth restriction
Intrinsic factor
Chromosomal abnormalitiesCongenital anomaliesIntrauterine infection
LOGO
Classification
1. Symmetrical growth restriction An early insult could result in a relative decrease
in cell number and size.• chemical exposure• viral infection• cellular maldevelopment with aneuploidy
It may cause a proportionate reduction of both head and body size.
LOGO
LOGO
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
Classification
2.Asymmetrical growth restriction Extrinsic factors : uteroplacental insufficiency
Maternal vascular disease: hypertension
Multiple gestations
Placental disease
Abruption, infarcts
Abnormal cord insertion, hemangioma
LOGO
Classification
2.Asymmetrical growth restriction – It might follow a late pregnancy insult such as
• placental insufficiency from hypertension– 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.
LOGO
Classification—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.
LOGO
LOGO
Classification
3. Combine type
Asymmetrical symmetrical Symmetrical asymmetrical
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.
LOGO
Cause
Fetal causesMaternal causesPlacental causes
LOGO
Fetal causesInfection
CMV, Rubella, Toxoplasma gondii – severe IUGR Syphilis, Tuberculosis, Malaria, listeriosis Herpes simplex, chicken pox
Chromosomal abnormality Trisomy 18,13 –severe IUGR Trisomy 21 Turner syndrome (45,XO), Klinefelter syndrome (47,XXY)
Cause
LOGO
Fetal causes
Congenital anomalies Congenital Heart diseases Anencephaly Renal agenesis, osteogenesis imperfecta
Cause
• Maternal malnutrition • Poor maternal weight gain• Severe anemia• Chronic hypoxemia• Cardiovascular disease• Drugs and teratogens• Multiple pregnancy• Antiphospholipid antibodies syndrome
Maternal causesCause
• Placental infarction• Placental abruption• Chorioangioma• Placenta previa , circumvallate placenta• Marginal or velamentous insertion of umbilical
cord
Placental causesCause
Fetal causes (intrinsic factors)
Symmetrical IUGR
Maternal causes Plcental causes (extrinsic factors)
Asymmetrical IUGR
Cause
Diagnosis
• Clinical assessment• Ultrasonic measurement• Doppler velocity
I. Clinical assessment• History for risk factor
– Socioeconomic factor– Smoking , Alcohol , Drugs– Previous IUGR pregnancy history– Family history : previous IUGR in family
Diagnosis
• Physical examination– Uterine fundal height
Uterine fundus Pubic symphysis Simple, Safe, Inexpensive for
screening 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• Physical examination
– Uterine fundal height– Maternal body weight
: BW<45 kg or : BW increased < 6.5 kg all over pregnancy
Diagnosis
Diagnosis
– Maternal underlying disease• Medical condition
– ภาวะขาดสารอาหาร– โลห ตจางอย่�างร�นแรง– ภาวะขาดออกซิ เจนอย่�างเร��อร�ง– โรคไตบางชน ด– โรคหลอดเล�อดในมารดา– Antiphospholipid antibody syndrome
• Obstetric condition– ครรภ์�แฝด
II. Ultrasonic measurement• Initial U/S at 16 to 20 weeks to establish
gestational age and identify anomalies and repeated at 32 to 34 weeks to evaluate fetal growth
Diagnosis
II. Ultrasonic measurement Abdominal circumference (AC) ***
– Sensitivity 90-100% , Specificity 95% (ด"ที่"$ส�ด)– < 5 th percentile
• Biparietal diameter (BPD)– Growth curve < 10 th percentile– Sensitivity to Symmetrical > Asymmetrical
• Head-Abdominal circumference ratio (HC/AC ratio)– Diagnosis for asymmetrical IUGR– HC/AC ratio > 2 SD
Diagnosis
II. Ultrasonic measurementDiagnosis
Femur length – abdominal circumference ratio (FL/AC ratio) - เป็&น age independent index ในที่ารกที่"$ GA>20 wks- จะม"ค�าคงที่"$เที่�าๆก�นที่�กอาย่�ครรภ( ค�อ 20-24% - ในราย่ที่"$ >24% ให)สงส�ย่ IUGR
Estimate fetal weight- < 10 th percentile
Diagnosis
II. Ultrasonic measurement Amniotic fluid volume
- ในภาวะ IUGR จะลดลงเป็&นอย่�างแรก- เก ดจาก renal perfusion ลดลง- Vertical pocket ที่"$ใหญ่�ที่"$ส�ด ได) < 1 cm. ถื�อว�าผิ ดป็กต - การตรวจพบน.�าคร.$าน)อย่อย่�างเด"ย่ว ไม�สามารถืว น จฉั�ย่ภาวะ
IUGR ได)ต)องร�วมก�บการตรวจอ�$นๆด)วย่
< 5th Percentile
< 10th Percentile
III. Doppler velocimetry• Abnormal umbilical artery Doppler velocimetry
– characterized by absent or reversed end-diastolic flow– associated with fetal growth restriction
A. Normal velocimetry pattern with an S/D ratio of <30.
B. The diastolic velocity approaching zero reflects increased placental vascular resistance.
C. During diastole, arterial flow is reversed (negative S/D ratio), which is an ominous sign that may precede fetal demise
Diagnosis
Prevention
• Stop and avoid all of the risk factors• Control maternal U/D• Antimalarial prophylaxis• Correction of nutritional deficiencies• Low-dose aspirin prophylaxis
– Hypertension– Prior IUGR history
Management
• Growth restriction near termPrompt deliveryRecommend delivery at 34 weeks or beyond if there
is clinically significant oligohydramnios
• Growth restriction remote from termNo specific treatmentIf 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 careIf severe IUGR or bad obstetric conditions
Terminate pregnancy should be considered
Management
Long-term sequelae
• Type 2 DM• Atherosclerosis• Hypertension• Heart diseases• Cerebral palsy• Learning deficits