Intrauterine Growth Retardation (IUGR)
Intrauterine growth retardation (IUGR) is diagnosed when an unborn baby is smaller than expected for their gestational age in weeks. A measurement below the 10th weight percentile qualifies the baby for the diagnosis.
A baby's birth weight is not only determined by how many weeks old he or she is, but also the rate at which the baby has grown. The way a baby grows, gains weight and develops is a very delicate process and if there is a disturbance or interruption in that process, the baby can suffer from growth restriction.
How Does the Doctor Diagnose IUGR?
The growth process of a baby is measured from the beginning by the doctor who assesses the size of the uterus during a pelvic examination in the first trimester. After the initial assessment, measurements of the belly are taken at every prenatal visit to determine the growth of the baby. If the measurements appear to be smaller than they should by standards for the date of gestation, then the doctor will order an ultrasound to get a fix on the baby's size and weight. It is possible for a baby to be small for date during the first half of a pregnancy because there is an error in due date, based on the last period. It is not uncommon for a mistake to be made in dates. However, if the ultrasound confirms the date, then the baby's growth will be monitored again by another ultrasound in a couple of weeks or so. If the baby's size seems to be slow in growing, IUGR may be diagnosed.
How Does IUGR Happen?
The reason a baby's growth is restricted is because the proper oxygen supply or nutrient supply isn't reaching him or her. Sometimes, although less common, genetic defects interfere with growth. Some of the most common causes of IUGR are:
· Placental abnormalities. The placenta may not be functioning properly if it is not formed well, is too small or is beginning to detach from the uterine wall (placental abruption).
· Preeclampsia or hypertension, kidney disease, heart disease, blood disorders like anemia, diabetes, clotting disorders, antiphospholipid antibody syndrome and lung disease are all medical conditions in the mother that can cause IUGR.
· Chromosomal abnormalities, structural birth defects, kidney or abdominal wall defects in the baby can cause IUGR.
· Carrying multiples - twins or more.
· Infections that can be passed from mother to baby such as STDs, toxoplasmosis, or rubella.
· Smoking, drinking and drugs.
· Certain prescription medications.
· Severe malnutrition (eating disorders included).
· Being underweight at time of conception and not gaining enough weight throughout the pregnancy can cause IUGR.
Any of these risk factors mean an ultrasound will be done to monitor the baby's growth, even if belly measurements are normal. A previous stillbirth or a baby born with IUGR will put the doctors on alert for IUGR in the current pregnancy.
How Does IUGR Affect the Baby?
Babies who are diagnosed with IUGR are subject to complications during the pregnancy, labor, delivery, and after their birth. The degree of risk is determined by the cause of the growth restriction, how serious the IUGR is and how early in gestation it began as well as the baby's gestational age at birth. According to research, a baby whose weight is below the 5th percentile is more inclined to have problems. IUGR babies who are born prematurely have even higher risk for both short and long term complications. Some of the risks include:
· Stillbirth due to reduced oxygen and nutrients
· Difficulty tolerating labor
· Increased risk of cesarean delivery
· Increased risk for meconium aspiration - where the baby swallows part of the first bowel movement during delivery.
· Low blood sugar
· Low resistance to infection
· Trouble maintaining body heat
· Polycythemia (high number of red blood cells)
· Hyperviscosity (decreased blood flow due to an increased number of red blood cells)
· Increased risk for motor and neurological problems
A mother can help her baby through pregnancy and birth by being diligent when it comes to attending prenatal and fetal testing appointments. Making the necessary adjustments to lifestyle early on (stop smoking, drinking, drugs) and keeping her weight at a normal and healthy level by eating properly and drinking enough fluids.