Birth by cesarean delivery and failure on first otoacoustic emissions hearing test

Neonatal hearing screening occasionally fails. We noticed that infants born by cesarean delivery (CD) appeared to fail the first otoacoustic emissions (OAE) test more frequently than infants delivered vaginally (VD). This might increase maternal anxiety. We aimed to evaluate the influence of mode of delivery on failure to pass the first OAE.

Overall, 1653 infants of >35 weeks' gestation were evaluated. OAE was performed before discharge. Perinatal-neonatal variables and results of OAE were recorded retrospectively.

Compared with VD infants, CD infants had lower gestational age and 1-minute Apgar, more small for gestational age (SGA), and earlier age at first OAE. Univariate analysis: CD, male gender, gestational age 35 to 37 weeks, birth weight ≤ 2500 g, SGA, and younger age at first OAE were significantly associated with failed first OAE. In infants weighing 2501 to 4000 g, CD infants had 3-fold higher rates of failed first OAE in comparison with VD infants (20.7% vs 7.1%) before 48 hours of age. In the multivariate analysis, variables independently significantly associated with failed first OAE were male gender (odds ratio [OR] 1.42 [1.02-1.98]), CD (emergency CD: OR 3.18 [2.21-4.57], elective CD: OR 3.32 [2.04-5.42]), age 12 to 23 hours at first OAE (OR 3.1 [2.1-4.58]) and SGA (OR 2.2 [1.15-4.28]).

CD infants had significantly higher failure rates on first OAE. We speculate that CD is accompanied by retained fluid in middle ear which may impair neonatal hearing. The timing of first OAE after CD should preferably be postponed beyond 48 hours of age to improve OAE passage and minimize maternal anxiety and costs.