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