Aim: Impulse noise causes severe neurological, psychiatric, cardiovascular, immunologic, endocrinologic disorders by causing neuronal injury in the cochlea, hippocampus, cerebral cortex and cerebellum. Occupational noise exposure causes to preterm birth, low birthweight, and malformations. We investigated if there is neuronal damage in brain of siblings of pregnant rats exposed to illegal impulse noise.

Methods: 3 male and 8 non pregnant female adult rats included. Three rat families were examined as control (A) and two of study groups (B,C). B family were exposed to 85 dB and C family were exposed to 120dB impulse noise at doses of 10×20 min/day in equal time intervals for 1 month. They were followed for 1 month. Delivered animals were separeted together with their siblings and followed for 1 month in their personal cages at the normal day-night cyclus. Birth weights of siblings were recorded at every weeks and all female rats and their siblings were sacrified under general anesthesia. Their brains were examined histopathologically and result were analysed by Mann-Witney U test.

Results: Seven rats of A family, six rats of B family and four rats of C family delivered between sixth and eighth weeks. The numbers of their living kids 7±2 in A, 5±2 in B and 3±1 in C family. Also, nonliving kid numbers of these families were 1±1, 3±1 and 5±2 consequtively. Body weight values of siblings were lower in B and especially C family. Brain volumes and neuronal densities of the hippocampus and cerebral cortex of the siblings of B to A and C to A&B families were lower. Differences of all parameters were meaningful (p<0.001).

Conclusion: We concluded that intense impulse noise may cause infertility, abortion, low birth weight, neuronal injury, cerebral immaturation and microcerebri. We proposed that pregnant women should be protected from intense impulse noise during pregnancy in order to have healthy babies.