The Roles of Formaldehyde Exposure and Oxidative Stress in Fetal Growth in the Second Trimester

Objective: To examine the relationship between formaldehyde exposure and fetal growth in the second trimester and the potential mediating role of oxidative stress in this relationship. Design: A cross-sectional study was conducted. Setting: The participants were recruited from one university-related clinic and two private obstetrics and gynecology offices in the Southeastern United States. Participants: A convenience sample of 140 healthy pregnant women in the second trimester of pregnancy was enrolled from November 2013 through June 2014. Methods: Formaldehyde exposure was measured via vapor monitors worn by the participants for 24 hours. One-time urine samples were collected during a routine prenatal visit to measure the level of 15-isoprostane F-2t and cotinine as biomarkers of oxidative stress and tobacco smoking, respectively. Urine creatinine was measured to standardize the cotinine and 15-isoprostane F-2t levels. Results: Eighty-eight participants (63%) returned their formaldehyde monitors. The linear regression model showed that the dichotomized level of formaldehyde exposure (<0.03 and >0.03 ppm) was a significant predictor of biparietal diameter percentile after controlling for maternal race (p < .006). The relationship between 15-isoprostane F-2t and fetal growth was nonsignificant, and the mediating role of oxidative stress in the relationship between formaldehyde exposure and biparietal diameter was not confirmed. Conclusion: A relationship was found between formaldehyde exposure and biparietal diameter in the second trimester. Although further research is necessary to confirm the results of this study, nurses may consider advising pregnant women to limit their exposure to formaldehyde during pregnancy.