On May 27, 2021, the Archives of Gynecology and Obstetrics published a preprint manuscript by Patrick Stelzl and others of the Johannes Kepler University Linz investigating the relationship between a pregnant patient’s use of plastic food packaging during pregnancy and the ultimate duration of the pregnancy and the baby’s birthweight. At eight times during the pregnancy participants answered a three-question survey to assess how often they were “drinking water from plastic packaging, food from plastic packaging and cans, and drinks from beverage cartons (TetraPak).” The researchers found no relationship between overall reported use of plastic food packaging and either pregnancy duration or baby’s birth weight.
Stelzl et al. surveyed plastic food packaging usage as a proxy for exposure to endocrine disrupting chemicals from food packaging. Endocrine disrupting chemicals (EDCs) such as phthalates and bisphenol A (BPA, CAS: 80-05-7) have demonstrable effects on the human hormone system and can migrate from food packaging into food and water (FPF reported). The chemicals can then be absorbed into the body, fetus, and breastmilk (FPF reported).
The pregnant survey respondents most often answered “almost never” when asked to rate how often they consume food from plastic packaging and cans. “Thus,” the authors stated, “the overall exposure of our patient collective to EDCs might rather have been intermediate to low.” Some EDCs activate the human hormone system only after concentrations reach a particular threshold (FPF reported). It’s possible that if plastic food packaging can have an effect on pregnancy duration or birth weight that the mothers in the survey did not attain that threshold concentration.
A recent peer-reviewed paper by Trnka et al. in Reproductive Toxicology investigated women’s exposure to di-2-ethylhexyl phthalate (DEHP, CAS: 117-81-7) in the United States and their self-reported infertility. According to the Food Packaging Forum’s Food Contact Chemicals database (FCCdb), DEHP is a priority hazardous substance. DEHP has been phased out in the European Union but is still used in the US to make plastic flexible including in food packaging and medical devices.
Trnka et al. used data from four years of the US National Health and Nutrition Examination Survey (NHANES) to assess the potential association between DEHP exposure and infertility in women. As part of the survey, urine was measured for four chemicals that DEHP is metabolized into in the human body, allowing the researchers a direct measure of DEHP exposure. The level of women’s DEHP exposure was split into four levels and comparatively analyzed with reported infertility. DEHP was associated with increased odds of infertility for the second and third quartiles when compared to the first quartile (which served as a reference), but no association was found between DEHP and infertility at the highest exposure level.
The authors state “our results for the highest [levels of DEHP metabolites] do not agree with findings from three prospective cohort studies, the first of which found a statistically significant linear relationship between higher DEHP metabolites and non-conception when comparing non-conception cycles with clinical conception cycles in the same woman.” They continue that DEHP may be one of a growing number of reported EDCs that have a non-monotonic dose-response relationship.
Stelzl, P. et al. (May 27, 2021). “Use of Plastic Packages for Food and Liquids in a prospective cohort of pregnant patients – Association analyses with birthweight and pregnancy duration.” Archives of Gynecology and Obstetrics (pre-print)
Trnka, B. et al. (May 28, 2021). “Exposure to Di-2-ethylhexyl phthalate (DEHP) and infertility in women, NHANES 2013-2016.” Reproductive Toxicology
Lagarde, F. et al. (February 11, 2015). “Non-monotonic dose-response relationships and endocrine disruptors: a qualitative method of assessment.” Environmental Health