Female noise exposure, shift work, and reproduction.

In addition to having possible direct effects on the fetus, noise induces a stress reaction in the mother, possibly causing reproductive disturbances. In shift work, many physiological functions and systems that are circadian in nature can be disturbed. Study results indicate that occupational noise at the level of approximately 85 dB LAeq(8 h) or higher and shift work, especially rotating schedules, may have independent negative effects on birth weight and length of gestation. Some forms of shift work have also been associated with early fetal loss. Moreover, some results have related noise exposure and shift work to menstrual disturbance and infertility. Although the evidence is not ample, it is prudent to consider exposure to high-level noise and shift work as risks to reproduction.