USA: Recent research has revealed that vitamin C supplementation can significantly improve placental function and alter gene expression in pregnant smokers, potentially benefiting the health of their offspring. The study, published in Scientific Reports, highlights the important role of vitamin C in addressing the adverse effects of smoking during pregnancy, which is known to compromise fetal development and increase the risk of various health issues.

Researchers utilized RNA sequencing to analyze the impact of vitamin C on placental tissue from pregnant smokers. The results indicated that supplementation led to notable changes in the expression of messenger RNA (mRNA) in genes that are crucial for vascular and cardiac development.
"These findings suggest a promising mechanism by which vitamin C may mitigate some of the detrimental effects of maternal smoking on placental function and, by extension, fetal health," the researchers wrote.
Smoking during pregnancy has long been linked to reduced blood flow to the placenta, resulting in insufficient nutrient and oxygen delivery to the developing fetus. This can lead to complications such as low birth weight, preterm birth, and lasting developmental issues, including reduced pulmonary function in offspring due to nicotine crossing the placenta. However, vitamin C supplementation during pregnancy has shown promise in preventing some of these adverse effects. Previous research in animal models exposed to prenatal nicotine suggests that vitamin C can enhance placental function, potentially mitigating the negative impacts of maternal smoking.

Against the above background, Eliot R. Spindel, Oregon Health & Science University, Beaverton, OR, USA, and colleagues aimed to determine whether vitamin C supplementation can mitigate the effects of MSDP on placental structure, function, and gene expression in pregnant women who smoke.
For this purpose, the researchers conducted Doppler ultrasound assessments on a subset of 55 pregnant smokers involved in the “Vitamin C to Decrease the Effects of Smoking in Pregnancy on Infant Lung Function” (VCSIP) randomized clinical trial, as well as on 33 pregnant nonsmokers.
The researchers found that Doppler ultrasound measurements indicated a reduction in umbilical vein Doppler velocity (Vmax) among smokers receiving placebo. However, those smokers who were given vitamin C showed a significant improvement, with their Vmax levels returning to those similar to nonsmokers.
This study highlights the potential benefits of vitamin C supplementation for pregnant smokers, specifically in improving placental blood flow. Enhanced umbilical venous flow is crucial for delivering oxygen and nutrients to the fetus, suggesting that vitamin C could mitigate some harmful effects of maternal smoking.
The researchers propose that vitamin C may counteract changes in vascular structure caused by nicotine, thus improving placental function and benefiting offspring's pulmonary development. RNA sequencing analysis indicates that vitamin C could activate key growth factor signaling pathways and promote blood vessel formation, reinforcing previous research linking placental DNA methylation to infant lung health.
"While these findings are promising, further clinical studies are needed to understand the practical implications of vitamin C supplementation in obstetric care. It remains unclear how these improvements in placental function may influence overall fetal development and obstetric outcomes," the researchers concluded.
"Notably, while vitamin C supplementation may help address some fetal health issues, it does not counteract all the negative effects of smoking, such as risks of prematurity and neural development challenges. Therefore, smoking cessation continues to be crucial for optimal fetal development in pregnancies where avoiding nicotine is not feasible."
Reference:
E., L., McEvoy, C. T., M., S., Milner, K., Vuylsteke, B., Tepper, R. S., Morgan, T. K., Roberts, V. H., Lo, J. O., Frias, A. E., Haas, D. M., Park, B., Gao, L., Vu, A., Morris, C. D., & Spindel, E. R. (2024). Vitamin C supplementation improves placental function and alters placental gene expression in smokers. Scientific Reports, 14(1), 1-13. https://doi.org/10.1038/s41598-024-73005-7