Intolerance to ambient odors at an early stage of pregnancy.

Adverse reactions to ambient odorous and pungent substances in daily activities among pregnant women who are half-way through pregnancy, and changes in odor perception at predominantly an early stage of pregnancy motivated the present study of odor intolerance at an early pregnancy stage. Ninety-five women averaging gestational week 11 and 102 non-pregnant women were compared with the Chemical Sensitivity Scale for Sensory Hyperreactivity (CSS-SHR). General environmental intolerance was assessed with items from the Noise Sensitivity Scale that are analogous to the CSS-SHR ("NSS-SHR"). Pregnant women were found to have higher scores on the CSS-SHR, but not on the "NSS-SHR". This suggests an odor intolerance that affects pregnant women's daily activities, which appears not to be due to a general environmental intolerance. The effect size of pregnancy on CSS-SHR score is larger in the present study of early pregnancy than in the previous study of women half-way through pregnancy.