Fig. 2: Exposure to e-cigarette vapors decreases embryo-to-placental weight ratios across the fetal-placental unit and may promote resorptions in the absence of nicotine.

After exposure to e-cigarette vapors until day 12.5 of pregnancy, embryo and placental weights were measured and averaged per litter and analyzed using one-way ANOVA with Tukey’s multiple comparisons test (a, b) (N = 11 SHAM, N = 14 VAPE, N = 12 VAPE NIC). Embryo/placental weight ratios were averaged per litter and analyzed using one-way ANOVA with Tukey’s multiple comparisons test (c) (N = 11 SHAM, N = 13 VAPE, N = 12 VAPE NIC). Embryo/placental weight ratios were also depicted individually as fetal-placental pairs and analyzed with one-way ANOVA and Tukey’s multiple comparisons test with a global ANOVA p-value = 0.0125 (d) (N = 82 SHAM, N = 86 VAPE, N = 90 VAPE NIC). Total resorptions or fetal death observed per uterus was graphed and tested using one-way ANOVA with Tukey’s multiple comparisons test (e) (N = 10 SHAM, N = 17 VAPE, N = 13 VAPE NIC). Resorption incidence across exposure was depicted as parts of a whole (f-g) (total uteri scored, N = 10 SHAM, N = 17 VAPE, N = 13 VAPE NIC) with (f) grey representing 0 resorptions, light pink as 1 resorption, pink as 2 resorptions, or dark red as \(\ge\)3 resorptions. SHAM depicted as black circles (a–d), white circles on black bars (e), or black bars (g); e-cigarette vapors without nicotine (VAPE) depicted as grey circles (a–d), grey circles on grey bars (e), or grey bars (g); e-cigarette vapors with nicotine (VAPE NIC) depicted as pink circles (a–d), pink circles on pink bars (e), or pink bars (g). Error bars indicate mean ± SEM. Red font p-values indicate significance with a p-value\(\le\)0.05. p adjusted p-value, Emb embryo, Plac placenta.