Figure 2:

Full term pregnant women were studied in a 2-night (n=17, panel A) inpatient protocol. White bars represent wake episodes under typical indoor light intensity (~90 lux), gray bars represent wake episodes under dim lighting (<15 lux), gray hashed bars represent 4-h experimental light exposure with either short- or long-wavelength visible light, and black bars represent sleep in dim lighting (<3 lux). Time-course of salivary melatonin levels under long- () and short-wavelength light () and uterine contractions under long- () and short-wavelength light () are shown for one individual (panels B-E). Unadjusted linear regression results testing the association between uterine contractions and salivary melatonin AUC are shown (panel F). Corresponding uterine contractions and melatonin AUC values from each individual are shown under long- () and short-wavelength light () conditions. Values from the first night are shown as filled symbols and values from the second night are shown as unfilled symbols.