Study identifies signals that may predict infant neurological impairment
Research Activities, July 2012, No. 383
Doctors use electronic fetal monitoring (EFM) when a woman is in labor to detect problems and prevent injury to the baby. However, because EFM tracks fetal heart rate (FHR) patterns and not neurological activity, its usefulness may be limited in preventing a birth-related neurological disability, such as cerebral palsy. A new study that examined FHR patterns finds that three other signals, when combined with routine EFM showing nonreassuring FHR patterns, may help predict whether a baby will be born with severe neurological damage.
Researchers compared 36 malpractice cases in which infants were born with birth-related neurological injuries after exhibiting certain FHR patterns, such as very rapid or very slow heart rates, with medical records of infants who also had these FHR patterns during labor but were born with no neurological problems. They found that 25 percent of the mothers whose babies were born with neurological injuries experienced vaginal bleeding before childbirth compared with only 1 percent of the mothers in the control group.
In fact, the odds of giving birth to a baby with neurological impairment were 27 times greater for women who experienced vaginal bleeding in the antenatal period and then had non-reassuring FHR patterns during labor than for women who had nonreassuring FHR patterns alone. The authors suggest that vaginal bleeding may indicate an abnormal placenta that could reduce the baby's oxygen supply during a stressful childbirth and result in neurological injury.
Half of the women whose babies were born with neurological injuries had an unusually long latent phase or delayed dilation during the first stage of labor compared with 25 percent of the control group's mothers. In fact, the odds of neurological injury to the baby were four times as great for the women experiencing longer first-stage labor and nonreassuring FHR patterns than for women who did not face prolonged first-stage labor in addition to their nonreassuring FHR patterns. Finally, the odds were also four times as great that a baby would suffer neurological impairment when the fetal monitor showed minimal heart rate variation along with nonreassuring FHR patterns during the first stage of labor than when the routine EFM showed nonreassuring FHR patterns alone.
The authors recommend future research to assess whether aggressive intervention could prevent neurological injury to infants when these signals are present. This study was funded in part by the Agency for Healthcare Research and Quality (HS11886).
See "Using malpractice claims to identify risk factors for neurological impairment among infants following non-reassuring fetal heart rate patterns during labour," by Aaron S. Kesselheim, M.D., M.P.H., Martin T. November, M.D., M.B.A., Karen L. Lifford, M.D., Sc.D., and others in the Journal of Evaluation in Clinical Practice 16(3), pp. 476-483, 2010.