Health Awareness blog

IUGR is diagnosed when the fetal weight is less than the tenth centile for gestational age. However, the diagnosis is highly relying on the accurate dating in early pregnancy.

IUGR is detectable after 28 weeks gestation and can be estimated by ultrasonography in utero. Ethnic variations in normal birth weight must be acknowledged. The same thing goes with the parental height and weight.

2 types of IUGR

• Asymmetrical IUGR – occurs in late pregnancy with placental insufficiency. There is sparing of head growth and other vital organs.
• Symmetrical IUGR – appears early in pregnancy when overall growth potential is reduced (e.g.: due to intrauterine infection or fetal abnormalities)

Etiology

Maternal causes:

• Smoking
• Pre eclampsia/hypertension (this will cause placental insufficiency)
• Placental abruption
• Renal disease
• Heart disease
• Alcohol/poor nutrition/low socioeconomic class
• Infections – rubella, syphilis, toxoplasmosis, varicella, cytomegalovirus, etc
• Severe anemia
• Age > 35 years
• Drugs or toxins – amphetamines, cocaine, ethanol, heroin, hydantoin, methotrexate, nicotine, propanolol

Fetal causes:

• Multiple pregnancy
• Chromosomal abnormalities – skeletal dysplasia (e.g.: achandroplasia, osteogenesis imperfecta), chromosomal deletions, Prader Willi syndrome, Russell-Silver syndrome, Trisomies 8, 13, 18 and 21, Turner syndrome (45, XO)
• Sickle cell disease
• Potter’s syndrome (renal agenesis)
• Anencephaly

Evaluation

• Take a careful history
• Make sure that the gestational age is correct and the baby is really small for gestational age and not just being a premature baby
• Do proper physical examination
• During pregnancy, the fundal height should be measure, and if noted to be small from suspected, further ultrasonography will be done
• In suspected case of IUGR, the fetal growth is monitored with ultrasonography to measure head and abdominal circumference
• Umbilical cord Doppler will be done to all suspected case of IUGR – normal result indicate better outcome of the baby
• Biophysical profile monitoring and antenatal cardiotocography is use to detect the baby that becoming hypoxic in utero. This baby would benefit from early delivery.
• Chromosomal analysis of the children may be done depends on the history and physical examination
• Skeletal radiographs will be obtained on children with disproportionate growth of upper and lower segment of the children.

Clinical features

• Poor maternal weight gain during pregnancy
• Oligohydramnios and poor fetal movement (this is the indication of placental insufficiency)
• “Small for dates” baby
• Slow growth of the fetus or children
• The growth might be disproportionate (meaning the ratio of upper body segment growth to lower segment growth is abnormal) – may be found in skeletal dysplasia. As a result, the affected children will have short limbs, trunks or both.

Labour and aftercare

• Hypoxia is common – so, proper monitoring should be done during labour
• After birth, monitor the temperature, IUGR baby easily become hypothermic. Babies that weigh <2kg should be put inside the incubator
• Jaundice is common – phototherapy may be needed
• Hypoglycemia is possible – IUGR babies have little glycogen storage. Feed the baby within 2 hours of life. Hypoglycemia should be prevented because it may lead to neonatal seizure and comatose. This baby should be transferred to special unit because they are also prone to infection.

Treatment

• 80-85% of infants with IUGR will experience “catch up” growth during first 3 months of life
• Those infants with continued short stature at 2 years of age is likely to remain short during adulthood
• 2/3 of short stature kids secondary to IUGR are noted to have GH (growth hormone) deficiency. However, the administration of supplemental human GH to increases the final adult height is remains controversial.
• Mother should be advise to stop smoking and take plenty of rest
• Do fetal kick chart

Complications:

• Increased perinatal mortality if intrapartum anoxia develops ( an ‘acute on chronic’ insult)
• Increased perinatal mortality caused by hypoglycemia, hypothermia and meconium aspiration
• Increased morbidity – evidence that ‘small for dates’ babies exhibit increased clumsiness, hyperactivity and language problems in childhood.
• Studies have been done to increase risk for hypertension, coronary artery disease, non insulin diabetes mellitus and autoimmune thyroid disease

Reference:

• Quick Reference Cards by Medical Protection Society. 2001.
• Clinical Handbook of Pediatrics.3^rd edition. Lippincott Williams and Wilkins.1999.
• Oxford handbook of Clinical Specialties. 5^th edition. 2001.