E-Cigarette Exposure Delays Implantation and Causes Reduced Weight Gain in Female Offspring Exposed In Utero.

Introduction:
This text reports a study examining the effects of e-cigarette exposure on pregnancy initiation and fetal health in mice. The study found that e-cigarette exposure delayed implantation and impaired the health of future offspring.

Key Points:

* Female mice exposed to e-cigarettes exhibited a delay in the onset of their first litter and a slight reduction in offspring number.
* Embryo attachment was delayed in e-cigarette-exposed mice, with fewer embryos implanting by day 5.5 of pregnancy.
* RNa microarray analysis revealed differential expression of pathways involved in embryo reception and ion transport.
* Male offspring exposed to e-cigarettes in utero had a slight reduction in fertility, but no testicular phenotype was identified.
* Female offspring exposed to e-cigarettes in utero had normal weight at birth but were significantly smaller at 8.5 months of age, with smaller inguinal fat pads and adipocytes.
* The study used a SCIREq inExpose whole-body inhalation system to expose mice to e-cigarette aerosol for 3 hours per day, five days a week, for four months.
* Progesterone levels and embryo implantation were assessed to evaluate pregnancy initiation, and RNa microarray was used to analyze gene expression changes.
* The study used C57BL/6J mice, and female mice were mated and exposed to e-cigarettes or sham treatment for four weeks before mating, and throughout pregnancy.

Main Message:
This study suggests that e-cigarette exposure can delay pregnancy initiation and impair fetal health in mice, indicating that e-cigarette use by reproductive-aged women or during pregnancy should be considered with caution. The study highlights the need for further clinical investigations to examine how e-cigarettes may affect pregnancy initiation and fetal health outcomes in women. The findings also suggest that e-cigarette exposure in utero may regulate metabolic function in adulthood, with potential implications for metabolic dysregulation. Overall, the study underscores the importance of understanding the potential health effects of e-cigarette use, particularly in vulnerable populations such as pregnant women and their offspring.

Wetendorf M, Randall LT, Lemma MT, et al. E-Cigarette Exposure Delays Implantation and Causes Reduced Weight Gain in Female Offspring Exposed In Utero. Journal of the Endocrine Society. 2019;3(10):1907-1916. doi:10.1210/js.2019-00216