Pregnant women may turn to maternity clothes for comfort but may wonder whether they need a new respirator in the workplace. Will their fit-tested facemasks still provide a tight seal if they gain weight during pregnancy? Results of a new National Institute for Occupational Safety and Health (NIOSH) study, accepted for publication by the Journal of Occupational and Environmental Hygiene, suggest that the fit-tested model of respirator provided before pregnancy will continue to fit a pregnant worker as long as she follows medical guidelines for healthy weight gain during pregnancy. A larger study is warranted to validate the findings, the researchers said.

In the United States, more than 3 million industrial workers and nearly 5 million nursing staff wear respirators to protect themselves from airborne toxins. As part of a workplace safety and health program, respirators can help stop airborne toxins from reaching the lungs when ventilation and cleaning measures alone cannot remove all contaminants, or if the cost of installing these measures is prohibitive. Because respirators must fit properly to function and significant changes in body weight can affect fit, the Occupational Safety and Health Administration requires annual fit testing. Whether pregnant women who wear respirators at work should undergo another fit testing was unclear prior to this study.

Researchers compared head and facial measurements and fit-test results of 15 voluntary participants in their second or third trimester of pregnancy to 15 voluntary, non-pregnant women similar in age, height, and weight. Besides measuring participants’ weight, height, and body-mass index, the researchers measured 13 head and facial dimensions that typically determine respirator fit. They then performed fit tests with N95 respirators, the most commonly used respirator in U.S. industry and healthcare. After comparing these detailed facial measurements and fit-test results between the two groups of participants, the researchers found no significant differences.

For more information, visit NIOSH Respirator Trusted-Source Information.

To read the unedited manuscript accepted for publication, go to: Effect of Pregnancy Upon Facial Anthropometrics and Respirator Fit Testing.