Hypoxic-ischemic encephalopathy (HIE) is a potentially serious brain disorder that results from a fetus receiving an inadequate supply of oxygen during pregnancy, labor, or delivery. A full and steady supply of oxygen is essential for the brain’s development; and, if a fetus’s oxygen supply is disrupted even for a relatively short period of time, this has the potential to cause health conditions including:
Prior to birth, the fetus’s oxygen supply comes from the blood delivered through the umbilical cord. As a result, umbilical cord problems are among the most common causes of HIE. During pregnancy, the mother’s doctor should monitor for signs of umbilical cord problems and should address any concerns promptly in order to ensure that the fetus continues to receive the oxygen required for normal brain development.
In particular, there are seven primary types of umbilical cord problems that can disrupt a fetus’s oxygen supply and possibly lead to HIE. If diagnosed promptly, all of these problems can be addressed with medical intervention. As a result, when a doctor fails to timely diagnose or treat one of these umbilical cord problems, the mother or family may have a claim for malpractice.
The umbilical cord is made up of connective tissue (called Wharton’s jelly), one vein, and two arteries. The vein supplies oxygenated blood to the fetus. Since the umbilical cord is soft and pliable, there is a possibility that it can become compressed in the womb.
When the umbilical cord is compressed, this can constrict the vein inside of it, and this can limit or disrupt the blood flow from the mother to the fetus. If a constriction lasts for an extended period of time (occasional minor constrictions are common during pregnancy and generally do not pose a risk to the fetus), this can result in HIE.
Umbilical cord compression can cause other complications and conditions as well. These include fetal acidosis and inadequate nutrition. If one of these other complications or conditions is observed in addition to HIE, then there is a strong chance that umbilical cord compression is to blame.
A prolapse of the umbilical cord occurs when the cord moves through the cervix and into the birth canal either before or with the baby during labor. If the umbilical cord enters the birth canal first, this is referred to as overt cord prolapse. If it enters the birth canal with the baby, this is referred to as occult cord prolapse.
Umbilical cord prolapse causes compression of the cord; and, due to the circumstances under which it occurs, emergency medical intervention will often be necessary. The mother’s doctor may need to attempt to reposition the umbilical cord or the fetus, use forceps or a vacuum extractor to speed up the delivery, or perform an emergency cesarean section (C-section) delivery.
There are a number of factors that can cause umbilical cord prolapse. When one or more of these factors are present, the mother’s doctor should advise the mother regarding the risks and carefully monitor for prolapse throughout labor. Risk factors for prolapse of the umbilical cord include:
When a prolapsed umbilical cord is compressed by the cervix or birth canal, this can disrupt the fetus’s oxygen supply just like umbilical cord compression in the womb, and this can potentially cause HIE.
Infections in the umbilical cord can also lead to HIE. Funisitis is an umbilical cord infection that occurs when an intra-amniotic infection, also referred to as chorioamnionitis, spreads from the fetal membranes to the cord. While funisitis only affects the Wharton’s jelly that surrounds the umbilical cord vein and not the vein itself, if the Wharton’s jelly becomes inflamed due to an infection, this can potentially cause compression of the vein and a reduced supply of oxygen to the fetus’s brain.
Funisitis is also often associated with fetal inflammatory response syndrome (FIRS). FIRS is characterized by inflammation of the umbilical cord and an elevated level of fetal plasma, and these can both increase the risk of a fetus experiencing HIE and other potentially-serious complications due to disrupted oxygen supply during pregnancy.
On average, an umbilical cord will grow to approximately 18 to 24 inches in length during pregnancy. If an umbilical cord is shorter than average, this can increase the risk of the umbilical cord tearing or rupturing in the womb. It can also increase the risk of the placenta tearing away from the uterine wall, which is a condition known as placental abruption.
If the umbilical cord or placenta tears or ruptures during pregnancy, this can potentially cause serious health risks for both the mother and the fetus. Maternal bleeding can result in inadequate blood flow to the fetus, and this means an inadequate supply of oxygen as well. As a result, HIE is a serious concern when the umbilical cord does not grow to its expected length, and it is up to the mother’s doctor to ensure that a short umbilical cord does not lead to life-altering or life-threatening complications.
Risk factors (which the mother’s doctor should identify prior to or during pregnancy) that can increase the risk of the umbilical cord failing to grow to a normal length include:
A nuchal cord occurs when the umbilical cord wraps around the fetus’s neck inside the womb. This is not always as dangerous as it sounds, and in many cases, babies are born completely healthy despite experiencing a nuchal cord in the womb.
However, a nuchal cord can be dangerous and potentially lead to hypoxic-ischemic encephalopathy. A nuchal cord can cause HIE if:
In addition to a single nuchal cord (when the umbilical cord is wrapped around the baby’s neck once), a double nuchal cord is also possible, and the umbilical cord may even wrap around a fetus’s neck more than twice. When the umbilical cord wraps around a fetus’s neck more than once, this can increase the risk of HIE (and other complications) resulting from an inadequate supply of oxygen to the fetus during pregnancy.
Abnormalities in the umbilical cord (such as being poorly structured or unusually long) can increase the risk of a nuchal cord, as can having a baby who is very active in the womb. Certain other factors can make a nuchal cord during pregnancy more likely as well. Again, the mother’s doctor should monitor for these types of risks; and, if a nuchal cord is identified, the mother’s doctor should promptly determine what medical intervention is necessary.
A true knot is exactly as it sounds: During pregnancy, the fetus moves in such a way that a knot is formed in the umbilical cord. If a true knot tightens, this can reduce or disrupt the oxygen supply to the fetus’s brain through the mother’s blood, and this can lead to hypoxic-ischemic encephalopathy.
Similar to nuchal cords and the other complications discussed above, doctors should monitor for signs of true knots during pregnancy, and they should be particularly cautious when certain risk factors are present. Some examples of these risk factors include:
If a true knot is identified (via ultrasound), then it may be necessary to admit the mother to the hospital so that the fetus’s oxygen supply can be closely monitored for the remainder of the pregnancy. If the fetus’s oxygen supply becomes restricted as a result of the true knot, then an emergency C-section may be necessary.
Vasa previa is a condition characterized by the vein and arteries of the umbilical cord not being completely encased in the Wharton’s jelly. There is an area between the placenta and the complete umbilical cord where the vein and arteries are exposed. When vasa previa occurs, there is an increased risk that the vein that delivers oxygenated blood to the fetus will be ruptured or torn, and this can result in HIE.
Like the other conditions discussed above, vasa previa can be diagnosed with an ultrasound. Due to the risks associated with vasa previa (including the risk of HIE), doctors must carefully examine ultrasounds for signs of this condition; and, if vasa previa is identified, a C-section delivery will generally need to be scheduled in order to avoid the risk of the exposed vein rupturing or tearing during delivery. Risk factors for vasa previa that should be identified during pregnancy include:
If your child has been diagnosed with HIE, it is important that you speak with an attorney about your legal rights. If your doctor should have done something to prevent your child’s condition, you may be entitled to a significant financial recovery. To speak with one of our Connecticut birth injury attorneys in confidence, please call us directly or contact us online today.