Objective: To explore the influence of night blindness during pregnancy on nighttime work activities of women.
Design and subjects: A community based case-control study was used to compare nighttime activities of night blind (cases) and non-night blind pregnant women (controls) using a 24h recall method to measure work activities (n=116 pairs).
Setting: Rural South-Eastern district in the plains of Nepal.
Results: Approximately one third of the night blind women reported being 'inactive' the previous night, not participating in any of the inquired work activities, as compared with only 15% of the control group (P < 0.031). The type of work that was significantly affected was the outdoor kind such as fetching water and washing dishes. Logistic regression analysis showed that night blind women were half as likely (odds ratio=0.49, 95% confidence interval=0.25-0.98) to work at night than women without night blindness after controlling for the effects of confounding variables including gestational age, season, and protein energy malnutrition which were significantly associated with nighttime work activity.
Conclusions: Night blindness during pregnancy, an indicator of vitamin A deficiency, reduces the number and type of work activities women perform at night, thus impairing women's ability to participate in normal subsistence activities by reducing their 'work day'.