Effect of analgesia with pethidine during labour on false positivity of newborn hearing screening test.

Objectives: Newborn hearing screening may fail due to some perinatal and neonatal factors. False positivity of newborn hearing screening increases costs, familial concerns and anxiety. The objective of this study was to determine the effects of pethidine administered in the mother for labor analgesia on the false positivity rates of the newborn hearing screening test.

Methods: This study was designed as a retrospective and cross-sectional study. A total of 75 pregnant women scheduled for vaginal delivery who received 50 mg intramuscular pethidine at the beginning of the active phase of the labor were included as the patient group and 68 pregnant women who did not receive pethidine as the control group. A total of 143 infants born with vaginal delivery were evaluated with otoacoustic emission (OAE) test before discharge. Perinatal and neonatal variables and test outcomes were recorded, and the correlation between false positivity rate and pethidine usage was evaluated.

Results: Initially, system records of 148 healthy term newborns were screened. Four patients who failed in both OAE tests and were referred to the Automated Auditory Brainstem Response (AABR) test and one patient who failed in all tests (first OAE, control OAE and AABR) and was referred to an upper center for further investigations and treatment were excluded from the study. No statistically significant difference was found between the groups in terms of birth features. First stage OAE test was reported as 'passed' in 8 (10.7%) and 58 (85.3%) newborns in the study and control groups, respectively; while OAE was reported as 'referred' and 'passed' in the second test in 67 (89.3%) and 10 (14.7%) newborns in the study and control groups, respectively. There was a statistically significant difference between both groups in terms of false positivity ratio (p < 0.5).

Conclusion: Pethidine significantly decreases the duration of the active phase, providing a good analgesic effect for pain management during labor. Therefore, it seems that pethidine can be used as an acceptable agent during labor. However, it may have neonatal effects after the delivery, causing false positivity in newborn hearing screening tests. The results of this study support the opinion that the OAE test should be performed in postpartum later dates in order to increase OAE passing rates and minimize costs and parents' concerns.