159 - Gestational Exposure to Electronic Cigarette Carriers Alone Results in Compromised Growth

Poster Number: 159
Publication Number: 159.311

Pedro Rivera-Hernandez, University at Buffalo, Buffalo, NY, United States; N Ja Hpa, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Buffalo, NY, United States; Justin Helman, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Bufalo, NY, United States; Sylvia Gugino, SUNY at Buffalo, Buffalo, NY, United States; Olivia R. White, University of Washington School of Medicine, Seattle, WA, United States; Sara Berkelhamer, University of Washington School of Medicine, Seattle, WA, United States

Background: Electronic cigarettes (EC) are perceived by many as safer than tobacco during pregnancy. Epidemiologic studies confirm high rates of dual use as well as a cohort who switch to vaping during pregnancy. These studies further suggest a lower risk of compromised fetal growth with EC as compared to tobacco (Aziz, AJOG, 2021). However, the consequences of gestational exposure to individual chemicals in EC remains poorly characterized, most notably the impact of chronic exposure to the carrier propylene glycol/vegetable glycerin (PGVG) alone.

Objective: To determine the impact of gestational exposure to aerosolized PGVG on pregnancy success rates, fetal and postnatal growth, as well as cardiopulmonary development.

Design/Methods: Time-mated C57Bl/6 female were exposed to aerosolized nicotine-free and flavoring-free 50%/50% PG/VG from embryonic day 0 (E0) through term cesarean or delivery (E19-20) in a programmable exposure system. Treatment included 10 x 70 ml puffs of PGVG aerosol delivered every 30 min x 16 cycles to parallel published clinical use. Outcomes were compared with sham-handled controls. Maternal consumption, weight gain, rates of pregnancy, litter size, and fetal weight with cesarean at E19 was evaluated. Birth weight was determined with delivered litters, followed by culling to comparable size for monitoring of postnatal growth. At P14, heart tissue was harvested with micro-dissection for assessment of right ventricular hypertrophy (RVH) by Fulton’s Index. Lung tissue was inflation fixed for analysis of vascular remodeling by medial wall thickness (MWT), alveolar development by alveolar area and chord length, and lung growth by radial alveolar count.

Results: Comparable food consumption and weight gain was documented with no difference in pregnancy rates following identification of a copulation plug (7/10 [PGVG} versus 14/17 [control]). Comparable litter size was also observed (9.2 ± 2.3 [PGVG] and 8 ± 0.8 [control]), with decreased fetal weight of PGVG exposed at E19 (0.84 ± 0.13 versus 1.26 ± 0.07 grams). Gestational exposure to PGVG further resulted in compromised postnatal growth with 8.2% growth failure by P14 (Fig 1). PGVG offspring had evidence of increased RVH at P14 (Fig 2) with a trend toward increased MWT. Morphometric analysis of lung tissue identified comparable mean alveolar area, chord length and radial alveolar count (Fig 3).Conclusion(s): While use of EC during pregnancy is common, delivery of nicotine via vaping may not represent a safe alternative. Exposure to the EC carriers, propylene glycol/vegetable glycerin alone may impact fetal and postnatal growth with associated RVH.
Fig 1: Compromised postnatal growth with gestational exposure to PGVGGestational exposure to PGVG resulted in 8.2% growth failure by P14. * p < 0.05.
Fig 2: Right Ventricular Hypertrophy with gestational exposure to PGVGGestational exposure resulted in evidence of RVH by increased Fulton's Index (weight right ventricle)/(weight left ventricle +septum). * < 0.05.