Hypoxic-Ischemic Encephalopathy and Medical Malpractice: Cord Prolapse, Nuchal Cord, and Placenta Previa
Hypoxic-Ischemic Encephalopathy (HIE), or birth asphyxia, is a serious condition wherein a lack of oxygen to a baby’s brain causes cell death and damage to the central nervous system, including the brain. This deprivation of oxygen typically is due to a lack of oxygen in the baby’s blood (hypoxia) and restricted blood supply (ischemia) to the brain tissue. These consequences can occur before, during, or after birth, and can lead to long-term conditions such as developmental delays, seizures, cerebral palsy, and periventricular leukomalacia (PVL). Even a few minutes of oxygen deprivation in a baby can cause severe problems. In general, the longer a baby is deprived of sufficient oxygen, the more severe and permanent the injury. The nature of the injury is dependent upon the area of the brain affected.
There are many long-term effects of HIE. Furthermore, brain damage may not become apparent until several years after the hypoxic-ischemic insult. In a study of school aged children with a history of moderate to severe HIE, 15% – 20% had significant learning difficulties, even in the absence of obvious signs of brain injury.
Due to the devastating impact of HIE, it is imperative that every effort be made by physicians to prevent hypoxia and ischemia in a baby. Complications involving the umbilical cord and placenta are common sources of hypoxic-ischemic injury in the newborn. A prolapsed umbilical cord, nuchal cord, and placenta previa are a few serious conditions that can cause HIE in a baby.
The Placenta and Umbilical Cord
The placenta is an organ that connects the baby to the wall of the uterus (womb), and facilitates nutrient uptake, waste elimination, and gas exchange through the mother’s blood supply. The umbilical cord arises from the placenta and is the conduit between the baby and the placenta through which these activities take place. Vital blood and oxygen flow to the baby through the cord. Dysfunction of the cord or placenta can cause the baby to suffer HIE.
What is a Prolapsed Umbilical Cord?
Normally, the baby exits the birth canal before or in front of the umbilical cord. Umbilical cord prolapse is an obstetrical emergency that occurs when the cord descends through the birth canal before (in front of) or alongside the baby. This usually occurs simultaneously with the amniotic sac rupturing (water breaking), as the baby is moving into the birth canal for delivery. This condition is life-threatening to the baby since blood flow through the umbilical vessels usually is compromised from compression of the cord between the baby and the uterus, cervix, or pelvic inlet. It is called an overt prolapse when the cord descends in front of the baby, usually through the opening of the cervix and into or beyond the vagina. In this case, the fetal membranes are invariably ruptured and the cord can be seen or felt. An occult prolapse occurs when the cord descends alongside, but not in front of, the presenting part of the baby. In this case, the membranes may or may not be ruptured. In both types of cord prolapse, there will be a fetal heart rate deceleration (decrease in baby’s heart rate below the baby’s baseline rate), which typically will be sudden and prolonged.
Once a cord prolapse occurs, the baby must be quickly delivered because the oxygen and blood supply is diminished or completely cut off. It is imperative that physicians recognize the condition and act skillfully in delivering the baby. In some instances, the physician will try to deliver the baby vaginally, while moving the baby away from the cord in order to relieve compression and pressure on the cord and reduce the risk of hypoxia and ischemia. Frequently, this course of action fails and an emergency C-section needs to be performed right away. While preparing for the C-section, the presenting part of the baby usually is pushed back into the pelvis to try and reduce the pressure on the cord. The cord must be elevated until the baby is out. The longer a baby’s oxygen and blood supply is diminished or cut off, the more likely it is that the baby will suffer from HIE. When attempts at delivery fail, there is even more deprivation. It is recommended that a baby be delivered within 12 to 20 minutes of the onset of heart rate decelerations to avoid permanent brain damage.
Video: Umbilical Cord Prolapse
Umbilical Cord Prolapse: Causes and Risk Factors
The major causes of and risk factors for umbilical cord prolapse are related to maternal/fetal conditions that lead to inadequate filling of the mother’s pelvis by the fetus. In addition, obstetrical interventions that cause membrane rupture can lead to cord prolapse.
- Rupture of the membranes. Whether occurring spontaneously or due to physician rupture (amniotomy), the forceful gush of fluid can carry the cord beyond the presenting fetal part. The highest risk of this occurrence is with preterm premature rupture of membranes, unengaged fetal presenting part (baby not descended past narrowest part of pelvis, called the ischial spines), and polyhydramnios (too much amniotic fluid). If the physician ruptures the membranes too early, the baby’s head is too high up in the womb. The fluid loss and unengaged head in the cervix allow the umbilical cord to drop in front of the baby, which can cause compression as the baby descends.
- Polyhydramnios. Polyhydramnios often is associated with an unstable lie or unengaged presenting part, as well as copious flow of amniotic fluid after membrane rupture.
- Malpresentation of the baby. Being in a nonvertex presentation (not head first – head not down in the birth canal) is consistently associated with a high risk of cord prolapse. Thus, vertex, transverse lies, and breech (especially footling breech) positions all are risk factors for cord prolapse.
- Prematurity. Premature infants have a higher rate of prolapse, probably due to the smaller size of the fetus relative to the amniotic fluid volume, as well as the fact that premature infants have a high frequency of malpresentation.
- Multiple gestation (twins, triplets, etc.). The risk of cord prolapse in a term twin pregnancy is confined to the second born, who has an increased probability of malpresentation. The first baby can push/pull out the cord of the next baby upon exiting the mother.
- Multiparity. When women have previously given birth, they are more likely to have a rupture of membranes prior to engagement of the presenting part, which makes it more likely for the cord to move in front of the baby.
Physicians should be aware of risk factors for cord prolapse, since it is such a serious condition, and a physician skilled in these types of births should be present. In order to decrease the possibility of hypoxic-ischemic injury, compression of the cord should be minimized by skilled maneuvers of the physician, and delivery should occur very quickly to relieve all pressure on the cord. Sometimes a vaginal delivery is prolonged, and forceps or vacuum extractors are used to facilitate delivery. These delivery tools have their own risks and can cause traumatic birth injury, such as intracranial hemorrhages (brain bleeds).
What is a Nuchal Cord?
A nuchal cord occurs when the umbilical cord gets wrapped around the baby’s neck. A loop of cord around the neck is a common finding. Type A nuchal cord is a loop that is 360 degrees around the neck, where the placental end crosses over the umbilical end, entangling the neck in a pattern that can become undone when the fetus moves. A type B nuchal loop is one in which the placental end crosses under the umbilical end in a knot that cannot easily become undone. Nuchal cords may form at any time and disentangle and possibly reform, or they may persist. In many cases, the nuchal cord can cause hypoxia and ischemia, decreased fetal development, meconium aspiration, and complicated delivery.
The mechanisms by which a nuchal cord can cause hypoxia and ischemia are:
- The tight entanglement around the neck causes restriction of the carotid artery (neck artery), depriving the baby’s brain of blood and oxygen.
- There is severe congestion of venous blood flow (blood returning to heart gets backed up).
- The umbilical vessels themselves get compressed when the cord becomes tightly pressed against itself or the back of the baby’s neck.
Treatment of a nuchal cord consists mainly of prevention of umbilical cord compression during delivery. A loose nuchal cord usually can be slipped over the baby’s head to decrease traction during delivery of the shoulders or body. If the cord is wrapped too tightly and this is not possible, there is a technique by which the physician can slip the cord over the baby’s shoulders. If this also is not possible, the physician may use the somersault technique, which causes the shoulders to be born in a somersault, with the cord being unwrapped after the baby is delivered.
If there is more than one loop or the loop is too tight and cannot be easily undone, the cord must be clamped and cut before delivery of the shoulders to ensure adequate oxygen supply to the baby.
If a vaginal delivery cannot promptly take place, an emergency C-section must be performed. A delay in delivering the baby can prolong the effects of the hypoxia and ischemia, thereby increasing the chances of permanent brain damage and HIE, as well as death of the baby.
Indeed it is crucial for physicians to be very skilled in the complex techniques required for delivery of a baby that has a significant nuchal cord. Physicians must closely monitor the baby during pregnancy and labor/delivery. A nuchal cord can be identified on an ultrasound. If a baby has decreased activity after week 37, which is the most common sign of a nuchal cord, an ultrasound should be performed. If the knot occurs during labor, an abnormal heart rate will be detected on the fetal monitor.
Nuchal Cords: Causes and Risk Factors
Nuchal cord formation may be related to excessive fetal movement, a long umbilical cord, or it may be a random event. The likelihood of a nuchal cord increases as the baby’s gestational age increases. Twins that share the same amniotic sac always have some degree of cord entanglement.
Risk factors for a nuchal cord that also should prompt an ultrasound include the following:
- The baby has nutritional deficits that affect the cord.
- The baby is large for gestational age (LGA) or macrosomic.
- The mother is carrying multiple babies.
- The baby has a long umbilical cord.
- There is too much amniotic fluid present (polyhydramnios).
- There is malpresentation, such as a breech or shoulder first position.
A nuchal cord is particularly serious when it is wound tightly around the neck, is wrapped around the neck more than once, or where there is additional cord compression, as can be the case when polyhydramnios is present. Other cord complications include cord prolapse and vasa previa, which occurs when an umbilical cord blood vessel crosses the cervix under the baby and is torn. In these circumstances, the baby is likely to exhibit signs of fetal distress marked by accelerations and decelerations on the fetal monitor, which is caused by hypoxia and ischemia.
Due to its potentially devastating consequences, physicians should be aware of nuchal cord risk factors, and an ultrasound should be performed if the baby has any signs of or risk factors for a nuchal cord. A physician skilled in these types of births should be present. In order to decrease the possibility of hypoxic-ischemic injury, compression of the cord should be minimized by skilled maneuvers of the physician, and delivery should promptly occur to relieve all pressure on the cord. A prolonged vaginal delivery can be very dangerous for the baby. The key in prevention of HIE is to deliver the baby as quickly as possible.
What is Placenta Previa?
Placenta previa is a condition in which the placenta either partially or totally covers the cervical opening, sometimes referred to as the “cervical os.”
A placenta previa is typically characterized as either:
- A complete placenta previa – where the placental tissue completely covers the cervical opening; or
- A partial or marginal placenta previa – where the placenta only partially covers the cervical opening.
Placenta previa typically is diagnosed during the first or second trimester of pregnancy by ultrasound. For many women, a partial or marginal placenta previa may resolve by the time the pregnancy enters the third trimester. In many instances, however, the placenta previa does not resolve, exposing both the mother and baby to significant risks of death and serious injury related to hemorrhagic placenta previa, such as HIE.
Hemorrhagic placenta previa is typically characterized by painless third trimester bleeding. Often, bleeding will occur with the cervical changes and related uterine contractions which naturally occur as the pregnancy advances through the third trimester. As a result, when the cervical opening becomes wider and/or uterine activity occurs, the placenta previa can become hemorrhagic, causing both the mother, and potentially the baby, to hemorrhage (bleed rapidly and uncontrollably). Because of this, physicians must closely monitor any mother diagnosed with complete placenta previa, and they typically need to deliver the baby by C-section well before the time when any uterine activity or related cervical changes occur.
Since a complete placenta previa will cover the cervical opening, vaginal delivery can never be safely attempted. Furthermore, mothers with complete placenta previa should never have digital pelvic examinations performed since such examinations can themselves result in potentially uncontrollable hemorrhage. It has long been recognized that placenta previa may cause life-threatening hemorrhage in less than fifteen minutes, and that the amount or extent of hemorrhage associated with placenta previa is often unpredictable. Furthermore, because a baby’s circulating blood volume is so low, fetal hemorrhage associated with placenta previa is particularly dangerous, and may lead to the baby’s death or HIE if delivery is not managed in a safe and expeditious fashion.
Placenta Previa: Signs and Treatments
The first sign of placenta previa may be bleeding during the second half of pregnancy, and contractions may also be present.
If the baby is preterm (<37 weeks gestation) and bleeding is not present or has subsided, then immediate delivery is unnecessary. However, if the baby is reasonably mature (>37 weeks gestation) and the mother is in labor, or if hemorrhaging is present, immediate delivery of the baby via C-section is necessary.
Placenta Previa: Risk Factors
The exact cause of placenta previa is unknown, although there are several risk factors for the condition, which include:
- Multiple pregnancy
- Previous surgeries involving the uterus, such as C-section, surgery for uterine fibroids, and D&C
- Prior placenta previa
- Age 35 or older
- Recurrent abortions
The serious nature of placenta previa requires careful evaluation, monitoring and preparedness by the physician. If a physician fails to diagnose or treat placenta previa, the baby and mother could have severe blood loss leading to death. Blood loss to the infant can cause severe hypoxia and ischemia, with resultant HIE. Listed below are issues that can lead to HIE:
- Failure to perform an ultrasound to diagnose placenta previa.
- Failure to continuously monitor the baby during an emergent placenta previa situation resulting in fetal hypoxia (birth asphyxia) to the baby.
- Vaginal delivery attempted when complete previa exists.
- Digital pelvic exam performed when complete previa is present, causing hemorrhaging.
- Delayed emergency C-section.
Umbilical Cord Complications, Placenta Problems, HIE, and Medical Malpractice Attorneys
The physician and medical team must be very knowledgeable and skilled at handling issues that arise during labor and delivery that can deprive the baby of blood and oxygen. The team must be adept and able to act quickly. Failure to properly monitor and treat the mother and baby during pregnancy, labor and delivery is negligence. Failure to follow standards of care and guidelines, and to act skillfully and quickly, also constitutes negligence. If this negligence leads to injury of the baby, it is medical malpractice.
The attorneys at Reiter & Walsh ABC Law Centers have many years of experience in birth injury cases, including prolapsed umbilical cord, nuchal cord, and placenta previa cases. If you experienced any of these complications during pregnancy and your child developed an injury such as HIE, we can help you. Our skilled attorneys will work tirelessly to get you the compensation you and your family deserve, and you pay nothing unless we win your case.
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