Intrauterine Growth Retardation (IUGR)

Intrauterine Growth Retardation (IUGR) (Dysmaturity or Small-for-Date)

Definition

Infant’s weight less than the tenth percentile of its gestational age.

Aetiology

Chromosomal and genetic disorders: e.g.
- Down’s syndrome.
- Turner’s syndrome.
- Renal agenesis.
Intrauterine infections: e.g.
- Cytomegalovirus.
- Rubella.
- Syphilis.
Maternal factors:
- Maternal malnutrition: due to,
  - Chronic infections.
  - Worm infestations.
  - Malabsorption syndrome.
  - Wasting diseases.
- Narcotic drug addiction.
- Cigarette smoking.
- Exposure to ionising radiation .
- Maternal anaemia.
- Rh-isoimmunization.
Uteroplacental vascular insufficiency: due to
- Maternal hypertension.
- Maternal diabetes.
- Chronic renal disorders.
- Partial abruptio placentae.
- Multiple pregnancy.
- Post-term pregnancy.

Types

Symmetric IUGR:
- Early stage of IUGR.
- The growth impairment involves all body structures including the internal organs.
- It is usually due to chromosomal, genetic or infective causes.
Asymmetric IUGR:
- Late stage of IUGR.
- The growth impairment involves the body but not the brain tissues "sparing effect", so the head is big in comparison to the body.
- It is usually due to chronic malnutrition and uteroplacental insufficiency.

Diagnosis

History: of any of the aetiological factors.

Examination may reveal:

Poor maternal weight gain or even weight loss during pregnancy.
Fundal level is lower than that corresponds to the period of amenorrhoea.
Oligohydramnios.
Underlying cause may be detected.
The neonate shows signs of dysmaturity as:
- underweight,
- dry wrinkled skin,
- meconium stains the foetus, placenta umbilical cord as well as the amniotic fluid.

Investigations

Ultrasonography: may show;
- Smaller biparietal diameter in serial measurements.
- Smaller abdominal circumference (measured at the level of bifurcation of the portal vein in the liver).
- Large head/abdominal circumference ratio in case of asymmetric IUGR.
- Congenital anomalies.
- Oligohydramnios.
- Doppler ultrasound: shows increased systolic / diastolic velocity ratio in the umbilical artery due to high resistance in the distal vascular bed in the placenta.
Daily foetal movement count:
- Less than 10 movements / 12 hours.
Antenatal cardiotocography:
- Non -stress test: non -reactive.
- Stress test: late deceleration.
Biophysical profile: see before.
Hormonal study: see before.
Amnioscopy: meconium stained liquor.

Management

Antenatal

Rest in bed in lateral position (better the left) to prevent IVC compression . This increases the placental blood flow by 25%.
Smoking should be discouraged.
Treatment of the underlying cause.
Monitoring of foetal wellbeing.
Termination of pregnancy according to the balance between risk of intrauterine asphyxia against those of prematurity.

Intranatal

Mode of delivery is influenced by:
- gestational age,
- result of the stress test,
- associated factors as malpresentations, antepartum haemorrhage, previous caesarean section ...etc.
- Caesarean section is more liberally indicated especially if there are associated adverse factors as the foetus does not tolerate the reduced oxygen supply and birth trauma encountered during vaginal delivery.
Continuous intranatal monitoring.

Postnatal

Identification and management of problems of dysmaturity as:

Hypothermia: due to relatively large surface area and lack of insulating fat layer
Asphyxia neonatorum: as an extension to the intrauterine asphyxia or due to meconium aspiration.
Hypoglycaemia: due to increased metabolic demands, especially in presence of chilling and poor glycogen reserves.
Hypocalcaemia: manifested by clonus, tremors or convulsions.
Haemorrhagic tendency: may cause pulmonary haemorrhage and death.
Stunted growth and mental retardation: more liable to occur in the future.

Links

Edited by Aldo Campana,