Dad's exposure to phthalates in plastics may affect embryonic development

December 07, 2016

AMHERST, Mass. - A new study led by environmental health scientist Richard Pilsner at the University of Massachusetts Amherst, one of the first to investigate whether preconception exposures to phthalates in fathers has an effect on reproductive success via embryo quality, found that exposures from select chemicals tested were associated with "a pronounced decrease in blastocyst quality" at an early stage in embryo development.

Phthalates are compounds found in plastics and personal care products that are estimated to be detectable in nearly 100 percent of the U.S. population. The authors believe theirs is the first prospective study to assess associations between paternal exposure to phthalates and embryo quality through the blastocyst stage in humans.

Pilsner and colleagues say their prospective study of 761 oocytes, or immature eggs, from 50 couples undergoing in vitro fertilization (IVF) "provides the first data demonstrating associations between preconception paternal phthalate and phthalate alternatives and embryo development, in a critical step towards our understanding of the paternal contributions to reproductive success." Details appear in the current issue of Human Reproduction from Oxford University Press.

For this investigation, the researchers recruited 50 couples from the Baystate Medical Center's Fertility Center in Springfield, Mass., as part of the Sperm Environmental Epigenetics and Development Study (SEEDS). They measured phthalate exposure in urine from male and female partners on the same day as semen sample procurement and oocyte retrieval, and assessed embryo quality at the cleavage (day 3) and blastocyst (day 5) stages.

The 50 couples contributed 761 oocytes, of which 423 progressed to the cleavage stage, 261 were high quality cleavage stage embryos, 137 were transferrable quality blastocysts and 47 were high quality blastocysts.

The researchers quantified concentrations of 17 urinary metabolites by liquid chromatography mass spectrometry, estimated odds ratios (OR) and confidence intervals with urinary phthalates and phthalate alternatives fitted as continuous variables and embryo quality as a binary variable.

At the cleavage stage, there were no overall significant associations for male or female phthalate exposures. Concentrations of male urinary monoethyl phthalate were positively associated with high quality cleavage stage embryos, with an OR=1.20 and no other significant associations were observed at this stage. At the blastocyst stage, ORs for male urinary concentrations of monobenzyl phthalate was 0.55 for mono-3-hydroxybutyl phthalate 0.37, for mono-n-butyl phthalate 0.55 and for monomethyl phthalate 0.39, all inversely associated with high-quality blastocysts.

"Although our results do not show altered embryo development associated with urinary metabolites at day 3, it is possible that the molecular changes associated with phthalates and phthalate alternatives were too subtle to be detected morphologically during these early cleavage stages and that such early molecular changes manifest at the morphological level during later stages of development," the authors say.

"Our modest sample included only 50 couples contributing one cycle each. In addition, non-differential misclassification of exposure remains a concern given the single spot urine collection and the short half-life of phthalates," they add. Overall, results support "the growing evidence that the preconception paternal environmental health may contribute to reproductive potential."

They add that "future studies are needed to investigate the long-term effects of altered embryo development" and to identify a mechanism by which a father's preconception exposure to phthalates may affect embryo development. "If corroborated with other studies, such findings will have public health and clinical significance for both the general population and those undergoing IVF."
This work was supported by a grant from the National Institute of Environmental Health Sciences. Pilsner collaborated with Dr. Cynthia Sites, director of the in vitro fertilization clinic at Baystate Medical Center, Springfield, Mass., to conduct this research.

University of Massachusetts at Amherst

Related Phthalates Articles from Brightsurf:

Researchers find connection between household chemicals and gut microbiome
A team of researchers for the first time has found a correlation between the levels of bacteria and fungi in the gastrointestinal tract of children and the amount of common chemicals found in their home environment.

A better alternative to Phthalates?
In collaboration with the Medical University of South Carolina, researchers at the National Institute of Standards and Technology (NIST) analyzed urine samples from pregnant women to look for the presence of DINCH, which is short for di(isononyl)cyclohexane-1,2-dicarboxylate.

Exposure to environmental chemicals may disrupt sleep during menopause
For menopausal women who have difficulty sleeping, it might be because of chemicals in the environment.

Environmental contaminants alter gut microbiome, health
The microbes that inhabit our bodies are influenced by what we eat, drink, breathe and absorb through our skin, and most of us are chronically exposed to natural and human-made environmental contaminants.

Prenatal phthalate exposure associated with autistic traits in young boys
Exposure in the womb to phthalates, a group of endocrine-disrupting chemicals present in cosmetics and other common household products, was associated with autistic traits in boys, ages 3 and 4, but not in girls, according to a new study led by a University of Massachusetts Amherst environmental epidemiologist.

Break point
Experiments in worms reveal the molecular damage caused by DEHP, a chemical commonly used to make plastics flexible.

Plasticizers may contribute to motor control problems in girls
Scientists at the Columbia Center for Children's Environmental Health (CCCEH) have uncovered a link between prenatal exposure to phthalates--a ubiquitous group of plasticizers and odor-enhancing chemicals--and deficits in motor function in girls.

Stress, plastic additives in late pregnancy raise risk of premature birth
Women exposed simultaneously to stress and plastic additives late in pregnancy are at increased risk for premature birth, according to a study by Rutgers and other institutions.

Bisphenol-a structural analogues may be less likely than BPA to disrupt heart rhythm
Some chemical alternatives to plastic bisphenol-a (BPA), which is still commonly used in medical settings such as operating rooms and intensive care units, may be less disruptive to heart electrical function than BPA, according to a pre-clinical study that explored how the structural analogues bisphenol-s (BPS) and bisphenol-f (BPF) interact with the chemical and electrical functions of heart cells.

Genetic inequity towards endocrine disruptors
Phthalates are used by industry in plastic products. Their toxic effect on the endocrine system is worrying.

Read More: Phthalates News and Phthalates Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to