Evaluating the brachial plexus birth injury case.
All parents look forward to the first time their child grasps a toy, waves goodbye, or tosses a ball. Yet these simple hand and arm movements can be rendered difficult, or even impossible, by a type of birth injury that in most cases can be prevented with proper obstetrical care.
Arm and hand dysfunction in varying degrees may result from injury to the brachial plexus--a group of nerves that run from the spine to the shoulder and control muscle movement in the shoulder, arm, and hand. These injuries usually occur during vaginal delivery or a large, or macrosomic, infant. The medical literature often refers to these babies as LGA (large for gestational age) infants.
The culprit is a condition called shoulder dystocia. When the baby is too large to pass unimpeded through the mother's pelvis, one of the fetus's shoulders may become lodged behind the mother's pubic bone after the head has been delivered. Further attempts to vaginally deliver the infant stretch the neck excessively, damaging the nerves running from the cervical and thoracic spine to the shoulder.
Studies report the incidence of obstetric brachial plexus injuries in the United States to be 0.5 to 2.6 per 1,000 live births.(1)
Attorneys evaluating a case for a potential client must consider three major factors affecting liability and damages: the severity of the child's injury., whether the doctor should have suspected a large baby and performed a cesarean section, and whether the doctor used the appropriate delivery techniques once shoulder dystocia was encountered.
A brachial plexus injury usually results from excessive traction on the baby's head during birth. The baby's neck and shoulders may stretch too far apart, causing tearing or other damage to the nerves.
Damage to the upper plexus (C5 to C7) is called Erb's palsy. Damage to the lower plexus (C8 to T1) is known as Klumpke's palsy. Total plexus injury--extensive trauma often affecting the face as well as the arms and hands--can also occur.(2)
The impairment to the child depends on the location and severity of the nerve damage. Children with Erb's palsy generally have little or no movement in the arm and shoulder. Those with Klumpke's palsy have little or no movement in the wrist and hand. In the worst cases, both impairments are present.
Pediatric neurologists identify at least four types of nerve damage, listed here from most to least severe:
* Avulsion: The nerve is torn from the spine.
* Rupture: The nerve is torn, but not where it connects to the spine.
* Neuroma: This develops after avulsion or rupture occurs. Scar tissue grows around the injured nerve as it tries to heal itself. The nerve cannot conduct signals to the muscles because of pressure from the scar tissue.
* Praxis: The nerve is damaged but not torn. This type will normally heal itself completely, without neuroma.
Because of the expense associated with litigating these cases, attorneys considering whether to take a case may want to wait a while after the birth to determine the severity of the nerve damage. Unless there is permanent injury, damages will probably not be sufficient to justify taking the case to court. An avulsed or ruptured nerve will usually result in some degree of permanent impairment to the child.
Predictors of a large baby
While it may be difficult for physicians to definitively predict shoulder dystocia, they should be on the lookout for predictors of a macrosomic fetus, defined as one with an estimated weight of more than 4,500 grams (10 pounds).(3)
* Gestational diabetes. It is universally recognized that gestational diabetes is associated with macrosomia.(4) This is partly because the principal agent of fetal growth is glucose. Also, fetuses of diabetic mothers have greater shoulder-to-head and chest-to-head disproportion than do fetuses of similar weight born to nondiabetic mothers.(5)
One study found that the incidence of shoulder dystocia was 31 percent in diabetics whose infants weighed more than 4,000 grams (about 9 pounds). The incidence rate for nondiabetics was only 10 percent when the infant weighed 4,000 to 4,499 grams and rose to 22.6 percent when the infant weighed 4,500 grams or more.(6)
The prenatal records should be examined to see if the mother was timely screened and treated for this condition. A diagnosis well into the third trimester leaves very little opportunity for effective treatment.
* Obesity. Obese women have a greater risk of giving birth to large infants. One study found that mothers of macrosomic infants typically weighed 90 kilograms (about 200 pounds) or more.(7) Thirty-three percent of the infants born to women in this weight group weighed 4,500 to 4,999 grams (10 to 11 pounds), and 50 percent weighed 5,000 grams or more. Shoulder dystocia was identified in 21.9 percent of these infants. Diabetes was also associated with macrosomia in this study.
While cesarean delivery poses risks for obese women, medical protocols call for the procedure when the mother is morbidly obese and when the fetus is diabetic and macrosomic.(8)
* Excessive weight gain. It has been reported that the incidence of macrosomia increases from 1.4 percent to 15.2 percent among women with excessive weight gain during pregnancy.(9) This is especially true for mothers over 30 years old.
When evaluating a case, the attorney must determine with the help of an expert the ideal weight for the mother given her height, build, and age. The young first-time mother will likely gain more weight than a woman who has given birth before. Therefore, excessive weight gain must be analyzed in connection with other predictors of large infants.
* The mother's age.(10) This risk factor has not received great emphasis in the medical literature. However, it has long been recognized that advanced maternal age is a risk factor in pregnancy. The mother over 30 is at an increased risk for obesity, diabetes, excessive weight gain, and post-term gestation, each of which places her at a greater risk for fetal macrosomia and shoulder dystocia.
* Previous large infant. Delivery of a large infant increases the risk that macrosomia will happen again,(11) so an attorney evaluating a case should request all prenatal and delivery records of previous births. Once again, this predictor is more probative if the mother is also obese or suffers from gestational diabetes. The attorney should investigate whether the obstetrician was aware of the circumstances surrounding previous deliveries.
* McDonald (fundal height) measurements. The medical records should accurately reflect the McDonald measurements taken during the mother's routine prenatal visits to her doctor. This is an external measurement from the top of the pubis to the top of the uterus. It is often referred to as the fundal height and is recorded in centimeters.
This measurement typically corresponds with the mother's week of pregnancy. For example, at 32 weeks, the fundal height is usually 32 centimeters, give or take 2 centimeters. If the mother consistently has a McDonald measurement greater than her week of pregnancy, the physician should anticipate a large baby.
The attorney should conduct a thorough investigation of the prenatal records to determine whether any of these predictors is present. If there are multiple predictors, the attorney can argue that the physician should have anticipated a large infant and avoided vaginal delivery.
The role of ultrasound
If the records reveal any macrosomia predictors, the case may hinge on whether the physician took steps to confirm if the infant is large. Most experts agree that ultrasound is the best diagnostic tool for determining the size of the baby. Some experts advocate the use of multiple ultrasounds when the clinical predictors are present.(12)
Although ultrasounds are routinely used to estimate fetal weight, studies report wide-ranging rates of accuracy and error.(13) Even so, there is little question that this technology has helped obstetricians diagnose fetal macrosomia.
Ultrasound measurements, usually expressed in grams, are obtained by adding the fetus's abdominal circumference and femur length. The abbreviated form of this measurement, AC + FL = (estimated weight in grams), may appear in the prenatal records. The attorney, with the help of an expert, must determine what the measurements suggest about the size of the fetus, depending on gestational age.
Even if the predictors of a large infant are not present, the plaintiff may have a viable case of obstetrical negligence if the physician failed to make use of proper delivery techniques once shoulder dystocia was encountered.
The most successful maneuvers to manage shoulder dystocia during delivery include suprapubic pressure, Wood's "corkscrew" maneuver, and the McRoberts maneuver. Suprapubic pressure and the Wood's maneuver are appropriate in cases of mild shoulder dystocia. Physicians may use the McRoberts maneuver when they encounter severe dystocia. The goal is to dislodge the impacted shoulder and deliver the baby without a brachial plexus injury.
* Suprapubic pressure. This maneuver requires the help of an assistant. Suprapubic pressure--external pressure slightly behind the pubic bone--is applied by an assistant while the obstetrician pulls gently on the free shoulder.
* Wood's "corkscrew" maneuver. This technique recognizes that pulling on the baby's head and neck is incorrect. Rather, the fetus should be rotated through the birth canal if shoulder dystocia is encountered. Using this technique, the physician delivers the free shoulder first by gently rotating it clockwise. This maneuver "unscrews" the impacted shoulder and allows it to be delivered.
* McRoberts maneuver. In this technique, the mother pulls her thighs up against her abdomen. Often an assistant must help hold the thighs. This maneuver repositions the pubic bone and frees the infant's impacted shoulder.
The attorney should review the labor and delivery records for documentation of these techniques. The lawyer should also conduct thorough interviews with family members or others who were present during the baby's delivery. These witnesses may be needed to refute the defendant's testimony that the proper techniques were used but were not documented in the mother's chart.
Evidence of improper technique may be just as important as evidence of failure to perform appropriate delivery maneuvers. Fundal pressure--pushing down on the top of the uterus--and pulling on the baby's head and neck are clearly contraindicated for a shoulder dystocia delivery. Once again, interviews with family members who were in the delivery room may be more telling than the medical records.
Battling the defenses
In most brachial plexus injury cases, defendants argue that shoulder dystocia is an obstetrical emergency requiring aggressive measures to deliver the infant before brain damage or death results. Physicians also typically argue that shoulder dystocia is difficult to predict before delivery and that brachial plexus injuries are caused by the natural forces of labor.(14)
The prudent plaintiff lawyer must rely on the medical literature, which provides substantial disagreement with the typical defenses. The focus at depositions and trial must be that even though opinions differ on the prediction of shoulder dystocia, well-established clinical and diagnostic techniques should not be abandoned.(15)
As in other areas of medical negligence practice, every brachial plexus injury case is different. Attorneys evaluating a case should consider the fundamentals discussed here: the severity of the infant's injury, the predictors of macrosomia, the delivery techniques used, and the likely defenses.
If, after carefully considering all the relevant factors, the attorney believes that a child was seriously harmed at birth by a physician's negligence, the attorney can take the case to trial confident that justice will prevail.
(1.) Gloria D. Eng et al., Obstetrical Brachial Plexus Palsy (OBPP) Outcome with Conservative Management, 19 MUSCLE & NERVE 884 (1996).
(2.) John Grossman et al., Management Strategies for Children with Obstetrical Brachial Plexus Injuries, 12 INT'L PEDIATRICS 82 (1997).
(3.) AMERICAN COLLEGE OF OBSTETRICIANS & GYNECOLOGISTS, TECHNICAL BULL. NO. 159 (1991) [hereafter ACOG BULLETIN].
(4.) James J. Nocon & Les Weisbrod, Shoulder Dystocia, in OPERATIVE OBSTETRICS 339, 343 (John Patrick O'Grady & Martin L. Gimovsky eds., 1995).
(5.) ACOG BULLETIN, supra note 3.
(6.) David B. Acker et al., Risk Factors for Shoulder Dystocia, 66 OBSTETRICS & GYNECOLOGY 762 (1985).
(7.) William N. Spellacy et al., Macrosomia--Maternal Characteristics and Infant Complications, 66 OBSTETRICS & GYNECOLOGY 158 (1985).
(8.) Thomas Benedetti, Protocol for Shoulder Dystocia, in ABSTRACTS OF THE SOC'Y OF PERINATAL OBSTETRICIANS, ABSTRACT NO. 111 (1989); JAMES A. O'LEARY, SHOULDER DYSTOCIA AND BIRTH INJURY: PREVENTION AND TREATMENT 20 (1992).
(9.) O'LEARY, supra note 8, at 35.
(10.) Id. at 13-16.
(11.) James J. Nocon et al., Shoulder Dystocia: An Analysis of Risks and Obstetric Maneuvers, 168 AM. J. OBSTETRICS & GYNECOLOGY 1732 (1993); see also S. Lazer et al., Complications Associated with the Macrosomic Fetus, 31 J. REPROD. MED. 501 (1986).
(12.) O'LEARY, supra note 8, at 48.
(13.) Herbert Sandmire, Whither Ultrasonic Prediction of Fetal Macrosomia? 82 OBSTETRICS & GYNECOLOGY 860 (1993); Ralph K. Tamura et al., Diabetic Macrosomia: Accuracy of Third Trimester Ultrasound, 67 OBSTETRICS & GYNECOLOGY 828 (1986); see also Greigh I. Hirata et al., Ultrasonographic Estimation of Fetal Weight in the Clinically Macrosomic Fetus, 162 AM. J. OBSTETRICS & GYNECOLOGY 238 (1990).
(14.) See Nocon & Weisbrod, supra note 4, at 347-50.
(15.) Id. at 352; see Stephen H. Mackauf, Responding to defenses in Erb's palsy cases, TRIAL, May 1998, at 53.
Lon Walters practices with the Law Offices of G. Spencer Miller in Kansas City, Missouri.
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|Date:||Jul 1, 1998|
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