IUGR- Intrauterine growth restriction/ retardation

Definition- Intra Uterine growth restriction is present in those babies whose birth weight is below the tenth percentile of the average for the gestational age.

Types- Based on the clinical evaluation and ultrasound examination the small foetuses are divided into-

1. Fetuses those are small and healthy.
2. Fetuses where growth is restricted by pathological processes.

Depending upon the relative size of their head, abdomen and femur, the Fetuses are subdivided into:

• Symmetrical or type I
• Asymmetrical or type II

◾Etiology-

1. Maternal diseases like Anaemia, hypertension, thrombotic diseases, heart disease, chronic renal disease are the important causes.
2. Toxins like alcohol, smoking, cocaine, heroin, drugs, are also responsible for IUGR.
3. Women with undernutrition are more likely to have IUGR.
4. Small women, maternal, genetic and racial background are associated with small babies.
5. Multiple pregnancies may also be responsible for IUGR.
6. Chromosomal abnormalities may be associated.
7. Poor Uterine blood flow to the placental site for a long time.

◾Diagnosis-

Clinical-

1. Clinical palpation of the uterus for fundal height, liquor volume and fetal mass may be used.
2. Symphysis fundal height measurement in centimetres. A lag of 4 cm or more suggests growth restriction.
3. Maternal weight gain remains constant or at times fall during second trimester or after that.
4. Measurement of abdominal girth shows stationary or falling values.

Physical features at birth-

1. Weight Deficit at birth is about 600 g below the minimum in percentile standard.
2. Length is unaffected.
3. Head circumference is relatively larger than the body in asymmetric variety.
4. Physical features show dry and wrinkled skin because of less subcutaneous fat, scaphoid abdomen, thin meconium stained vernix caseosa and thin umbilical cord. All these give the baby an “old man look”.
5. The baby is alert, active and having normal cry. Eyes are open.
6. Reflexes are normal including Moro-reflex.

◾Management- Fetuses that are constitutionally small require no intervention. The fetuses that are symmetrically growth restricted, should be investigated to exclude fetal anomalies, infections and genetic syndromes.

Unfortunately there is no therapy for this group. Finally the growth restricted fetus owing to placental disease or reduced placental blood flow (chronic placental insufficiency), may be given some treatment.

However, assessment of fetal
well being is more critical in the management as in majority there is no definitive therapy.

😊At present, there is no proven therapy for reversing growth restriction once it is established.
However the following may be tried with some success:

• Adequate bed rest especially in left lateral position.
• To correct malnutrition by balanced diet: 300 extra calories per day are to be taken.
• To Institute appropriate therapy for the associated complicating factors likely to produce growth restriction
• Avoidance of smoking, tobacco and alcohol.
• Maternal hyperoxygenation at the rate of 2.5 L/min by nasal prong, for short term prolongation of pregnancy.
• Low dose aspirin (50 mg daily) may be helpful in very selected cases with history of thrombotic disease, hypertension, pre-eclampsia, or IUGR
• Maternal hyperalimentation by amino acids can improve fetal growth if it was due to maternal malnutrition. It is not helpful when placental function is deficient.
• Maternal volume expansion may be helpful in improving placental perfusion.

◾Timing of delivery- If pregnancy > 37 weeks, delivery should be done.

Pregnancy < 37 weeks-

(a) Uncomplicated mild IUGR : Fortunately, the majority falls in this group. Usual Treatment as outlined above to improve the placental function may be employed. The condition may be reversed
and in such cases, the pregnancy is allowed to continue till at least 37 weeks. Thereafter delivery is done.

b) Severe degree of IUGR

• Delivery should be planned on the basis of fetal compromise.
• If the lung maturation is achieved as evidenced by presence of phosphatidyl glycerol and L:S ratio of
  22 from the amniotic fluid study (amniocentesis), delivery is done.
• If the lung maturation has not yet been achieved one has to face dual problems – one of prematurity and the other of growth restriction.
• Preterm IUGR fetus requires highest level of neonatal intensive care unit (NICU). Intra uterine transport to an equipped centre is ideal in such a case.
• Betamethasone therapy (see p. 316) is given to accelerate pulmonary maturation when gestational age is less than 34 weeks.
• Corticosteroids reduce the risk of neonatal HMD and intraventricular haemorrhage (IVH).

Methods of delivery-

• Low rupture of the membranes followed by oxytocin is employed in cases such as pregnancy beyond 34 weeks with favourable cervix and the head is deep in the pelvis. Prostaglandin (PGE2) gel could be used when the cervix is unfavourable.
• Intrapartum monitoring by clinical, continuous electronic and scalp blood sampling is needed as the
  risk of intrapartum asphyxia is high.
• Caesarean delivery without a trial of labour is done when the risks of vaginal delivery are more (presence of fetal acidaemia, absent or reversed diastolic flow in umbilical artery or unfavourable Cervix).