Effects of maternal preeclampsia on brain-stem auditory evoked response in very low birth weight infants

Because stress in utero may enhance neuromotor maturation, we hypothesized that infants born to mothers with preeclampsia would have a shorter absolute latency V and interpeak latency I-V period (brain-stem conduction time) of brain-stem auditory evoked response (BAER) than infants born to normotensive mothers.

A retrospective cohort study was performed to assess the effects of maternal preeclampsia on BAER of very low birth weight infants. The cohort consisted of 24 infants with a birth weight less than 1251 gm born to mothers with preeclampsia, and 48 infants born to normotensive mothers, matched for birth date within 2 months, gestational age, and chronologic age at the time of the BAER test. The BAER test was completed before discharge, with the infant in a quiet state and the use of a 30 dB stimulus.

The mean latencies of wave V were shortened bilaterally (left 8.60 +/- 0.6 msec vs 9.02 +/- 0.6 msec, p < 0.008; right 8.61 +/- 0.6 msec vs 8.96 +/- 0.6 msec, p < 0.033, and the interpeak latency of I-V was significantly shortened compared with the control subjects on the left (left 4.91 +/- 0.5 msec vs 5.38 +/- 0.6 msec, p < 0.003; right 5.17 +/- 0.5 msec vs 5.37 +/- 0.6 msec, not significant).

These results suggest that the intrauterine stress of maternal preeclampsia accelerates the maturation of the auditory nerve and brain-stem auditory pathway in very low birth weight infants.