Intrauterine growth restriction or retardation (IUGR) is defined as infants who fail to grow as expected during pregnancy, weighing less less than the 10th percentile of the normal weight range. The abdominal circumference is typically less than the 2.5 percentile. During the prenatal period, physicians are responsible for monitoring the baby’s growth, and if IUGR is detected, there is a sharp difference in the fundal height and weight when compared to other infants with the same gestational age.
There are an array of reasons why an infant may develop IUGR. Some of the most common include:
- Placental Abnormalities: If the placenta fails to function properly, the infant may not be able to get adequate oxygen and nutrients.
- Preeclampsia: Preeclampsia has been associated with a heightened risk of IUGR, especially during the second trimester.
- Chromosomal Disorders: Any chromosomal defect, such as Down’s Syndrome or ancephaly, may lead to IUGR.
- Maternal Infections: Infections including rubella, toxoplasmosis, and syphilis has been linked to a heightened risk of IUGR.
- Carrying twins
- Smoking during pregnancy
- Drug use during pregnancy
The prescription medication Depakote has been to linked to a heighten risk of IUGR. Depakote is typically used to treat conditions such as epilepsy, seizures, manic depressive disorders, and bipolar disorder, but when taken while pregnant, infants may are at risk of not only IUGR, but also:
- Spina Bifida
- Neural Tube Malformation
- Stillborn (fetal death)
Lexapro, a medication that treats depression, anxiety disorder, and social phobias, has also been linked to IUGR. In fact, a study performed by the National Institutes of Health (NIH) states that a little over 17% of infants born to mothers who took Lexapro while pregnant were small for their age. The infants exposed to Lexapro had smaler head sizes, lower birth weights, and smaller lengths than the average infant within the same age range.
In some instances, there is no known cause for IUGR. Experts suggest that in these cases, the parents may be smaller than average or live in an area with an higher altitude, leading to unusually small infants.
IUGR Risk Factors
Infants diagnosed with IUGR may have severe complications during labor and delivery. The complications will greatly depend upon the reason IUGR developed and when the infant started experiencing growth issues. One of the most severe issues is a stillborn birth, which typically occurs when an infant’s weight is below the 5th percentile.
Most infants with IUGR are usually delivered via C-section. Due to the their size, infants with IUGR have a difficult time in normal deliveries. Yet, C-sections bring on their own set of risks, including the risk of birth injuries, breathing problems and low APGAR scores.
Other risk factors include:
- Low blood sugar
- Difficulties in maintaining normal body temperature
- Unusually high red blood count
- Meconium Aspiration
- Cerebral Palsy
- Learning disabilities
IUGR Diagnosis and Treatment
In some cases, IUGR can be treated and reversed, if caught early enough. Before treatment starts however, your physician will usually perform several ultrasounds to check for normal organ development and normal movement. In addition, your doctor will also monitor your baby’s heart rate and conduct doppler flow studies to ensure the infant’s blood flow is working correctly. These tests are perform beforehand so that your physician can try to pinpoint the reason IUGR occurred.
Treatment options will depend upon what caused IUGR in the first place, but the one of the most common forms of treatment is placing pregnant women on bed rest, which can help the baby’s circulation.
Low doses of aspirin (150 mg or less per day) has been shown to improve fetal weight and head circumference if taken during the third trimester. However, according to NIH, taking aspiring, starting during the first trimester, reduces the risk of IUGR. The study also showed a significant reduction in preeclampsia, a condition that has been linked to IUGR. Yet, some doctors don’t recommend regular aspirin usage while pregnant. It’s important to discuss the benefits and risk with your own physician, as each pregnancy is different.
In other instances, the only form of treatment may be to induce labor early. This is usually reserved for severe cases in which the infant is failing to thrive and would be better off with physician assistance once born. Although there are typically a host of medical issues a preterm infant may face, it’s normally less than the risks associated with saying in utero yet failing to grow and thrive. If infants aren’t receiving adequate nutrients and oxygen while in utero, there is a chance fetal death will occur, and the only way to prevent it is via early labor induction and delivery.
Unfortunately, there is currently no known way that will prevent IUGR, but there are certain steps that you can to help reduce the risk, including:
- Eating healthy and taking appropriate prenatal vitamins
- Not smoking or partaking in drug use
- Keeping prenatal appointments
Labor and Delivery Complications
According to the American Academy of Family Physicians (AAFP), at least one half of all infants born with IUGR will experience intrapartum asphxia at birth. Meconium aspiration and fetal hypoxia is also common. Studies suggests that C-sections are more appropriate for infants with IUGR due to these risk factors and as mentioned earlier, due to their small size.
AAFP suggests that most infants with IUGR have a positive prognosis, with many catching up in growth within the first three months after birth. However, studies show that infants may be susceptible to clumsiness, hyperactivity, and poor listening skills. In addition, infants born with IUGR are at an increased risk of developing long-term problems with Type 2 diabetes as adults, as well as abdominal obesity and hypertension.