Evaluating Cases of Brain Damage at Birth Due to Perinatal Injury

By Robert A. Zielke

A difficult delivery and incompetent care by an obstetrician are cornerstones of the story a plaintiffs attorney often hears from the parents of a brain damaged child. The question is this: which cases are meritorious or deserve in-depth evaluation?

Several factors make proving a birth injury case difficult. First, one to two newborns in every 1,000 births develop cerebral palsy as a result of brain damage. These statistics have remained unchanged for the last 20 years. This sample might, however, reflect a larger number of early premature infants that are now surviving. Second, the cause of cerebral palsy in children is unknown in 80 percent to 85 percent of the cases. Only 10 percent to 15 percent of children with cerebral palsy are the result of lack of oxygen during the birth process (perinatal asphyxia). Finally, experts remain divided on whether electronic fetal heart monitoring has improved fetal outcome and statistically prevented brain damage.

A meritorious birth injury case needs two major factors: clean and easily understandable negligence, and strong evidence of birth asphyxia to overcome a litany of other causal events raised by defendants. Thus, the plaintiffs attorney should focus on the small percentage of cases that are due to lack of oxygen. It is often these cases where brain damage is preventable.

Causation Evaluation

Until the question of whether the brain damage was preventable is answered, the attorney can delay evaluating negligence theories. Causation is a key issue in birth injury cases, as in nearly all medical negligence actions. In a birth injury case, defendants will raise many causal theories, including unpreventable causes of cerebral palsy which occur during fetal gestation.

The attorney should focus upon lack of oxygen during the birth process, and ask if there is clear evidence of perinatal asphyxia. Medical literature indicates that several criteria identify infants who developed brain damage as a result of decreased oxygen during labor and delivery. These criteria can be summarized as (1) a blood pH of less than 7.0, (2) a five-minute or longer APGAR score of 3 or less, (3) evidence of neurologic injury within the first 24 hours of life (typically meaning seizures), and (4) other organ damage consistent with decreased oxygen, such as kidney damage.

Birth injury cases in which the above criteria are present deserve thorough evaluation of causation and negligence.

In evaluating causation, the attorney must be aware of two types of acidosis: metabolic and respiratory. Since respiratory acidosis does not necessarily lead to brain damage, strong evidence of metabolic acidosis is needed. To assess metabolic acidosis, the attorney should look at the blood gas studies and pay particular attention to whether buffer components in the blood are decreased. Base excess values represent the buffer system. If the acidosis at birth is respiratory in nature (meaning a small or insignificant metabolic component), brain damage is less likely to occur. Current medical literature indicates that respiratory acidosis at birth does not necessarily lead to brain damage.

Other causal theories will need to be ruled out once it is determined that birth asphyxia is a likely cause of the childs brain damage. CT or MRI scans are important in ruling out other causal events. Once the attorney has obtained the actual films, a neuroradiologist should be retained for consultation. Neuroradiologists can advise the attorney whether or not the injury evidenced on the MRI occurred to a mature brain, indicating birth asphyxia as the cause of the brain damage. One key radiological pattern that must be determined is periventricular leukomalacia (PVL). If a hypoxic event occurred between 27 and 34 weeks, gestation (normal term pregnancy being 40 weeks), damage to the periventricular region is a classical finding. The 40-week, or full-term, birth asphyxial case should not include evidence of PVL. It is very uncommon to find PVL after 34 weeks gestation.

The entire course of the pregnancy must be evaluated to look for evidence of events which could have produced brain damage. The birth asphyxia case should not include any evidence of decreased fetal movements, trauma, or chemical insults occurring during the pregnancy. Any fetal ultrasound examinations should be nominal both for anatomy and for fetal size to gestational age.

The mothers habits during the pregnancy must be evaluated. typically defendants will assert thats a mothers smoking causes placental damage that decreases fetal reserve. Other maternal factors that should be addressed include alcohol consumption, nutritional status, medication exposure, and use of illicit drugs.

Negligence Evaluation

To convince a jury of your liability theory, strong evidence of obstetrician negligence is needed. Typical obstetrical negligence consists of inappropriate or no intervention in the face of clear evidence of fetal distress. Fetal distress is typically diagnosed from electronic fetal heart monitoring.

The attorney must understand the basics of fetal heart monitor interpretation to review the strip, as well as to discus the strip with experts. Common strip indicators of fetal distress include late decelerations and decreased short- or long-term variability. Another important indicator is a heart rate outside normal range of 120-160 beats per minute; a very slow or very fast heart rate must be perceived as a red flag.

The jury will need strong evidence of fetal distress to be convinced that obstetrical intervention was required. Since the jury will be learning fetal heart monitoring during the trial, the evidence must be clear so that the jury members feel comfortable in finding negligence on the part of the obstetrician. The pattern on the monitor strip needs to be distinct enough or show enough minus signs that the jury can make the diagnosis and say that a reasonably prudent physician would have intervened to prevent catastrophic brain damage.

Obstetrician negligence can take two basic forms: failure to perform a C-section, or failure to perform fetal testing to assess acidosis or asphyxia. The decision to perform a C-section is based on risk/benefit analysis: do the benefits to the fetus outweigh the risk of a major surgical procedure performed on the mother?

Testing to assess the babys status during labor can take several forms. Common examples include fetal scalp pH testing, and fetal scalp stimulation. Fetal scalp pH testing is a direct measurement of the acid-base status of the baby, and is highly useful in determining if the child needs to be immediately delivered. For this test, a blood sample is obtained from the fetal scalp and sent to the lab, which reports back the pH of the blood.

Fetal scalp stimulation involves painfully stimulating the head of the child while in the birth canal. If the child is not in severe distress (i.e., acidotic), this painful stimulation should cause an acceleration in the fetal heart rate. Acidosis develops in children who are not receiving adequate oxygen; thus absence of an acceleration after scalp stimulation generally indicates fetal distress. Scalp stimulation is an indirect method of assessing fetal well-being and must be performed during the baseline portion of the fetal heart rate to determine if an acceleration occurs. Generally, fetal accelerations on an electronic fetal heart monitor are considered reassuring patterns that indicate lack of fetal acidosis.

Other factors which increase the risk of fetal distress should not be overlooked. Common factors increasing the risk of fetal compromise include a post-term pregnancy, abruption of the placenta, placental abnormalities, and decreased amniotic fluid indicating placental insufficiency. The presence of any of these factors might indicate intervention at an earlier time and/or the need for greater scrutiny of the electronic fetal heart monitor.

Liability theories regarding obstetrical nurses should be addressed. Obstetrical nurses are highly skilled in interpreting signs of fetal compromise. Often the obstetrician will rely upon the nursing staff to appropriately recognize fetal compromise and alert the physician. The physician will then make an assessment of the situation. Thus, the nurses care must be scrutinized to make sure they acted in a reasonably prudent fashion.

Expert Consultation

Appropriate experts will need to be retained to evaluate the case and testify at trial. A perinatologist, being a subspecialist in obstetrics, is typically the expert with whom to begin an evaluation. A perinatologist can evaluate the management of labor and can offer opinions regarding the causal nature of the childs injury.

A neuroradiologist will be utilized to explain and interpret CT and MRI findings. In the event that an MRI has not been performed, the neuroradiologist can perform an MRI - even years after the event - which is beneficial in determining the cause of the brain injury.

A pediatric neurologist is utilized to address causation issues and demonstrate that the type of cerebral palsy the child exhibits is consistent with your theory of birth asphyxia.

Experts will be needed to build the damage portion of any birth asphyxia case. A developmental pediatrician can be used to explain the profound nature of the brain damage and the current level of functioning of the child compared to the childs chronological age. In profound cases, it is not uncommon to see a four or five-year old child functioning at the level of a one-year old or less.

A rehabilitation nurse is utilized to formulate a life care plan for future medical care needs and the cost of future car. An economist is then used to calculate the cost of future medical services and wage loss, reducing those amounts to present value.

Conclusion

A birth injury case presents an intellectual challenge in determining whether it deserves in-depth review or is meritorious, as well as the later challenge of persuasively presenting the case to a jury.

In evaluating a birth injury case, plaintiffs attorney should look for persuasive evidence of profound birth asphyxia and failure by the obstetrician to prudently deliver the child or assess fetal well-being at appropriate times. The attorney must have an underlying understanding of pregnancy management and the pathophysiology surrounding multiple causal events producing brain damage. Careful case selection is imperative, because 80 percent to 85 percent of all medical negligence cases taken to trial result in a defense verdict.

Zielke, Trial News, Washington State Trial Lawyers, Vol. 30, No. 5, at 1 - January 1995