In vitro fertilization (IVF) has been getting a lot of media attention lately, as courts argue about whether frozen embryos constitute people and are therefore worthy of legal protection.
The controversy comes at a time when more couples than ever rely on this process to start a family. The practice accounts for more than 5 percent of live births in some European countries, where it is more affordable or covered by insurance, and nearly 2 percent of U.S. births. As rates continue to rise, it is expected that up to 10 percent of all children will soon be conceived through IVF in some parts of the world.
Based on existing science, it only gets worse looking into the future. The World Health Organization estimates that 60 to 80 million couples suffer from infertility worldwide, with one in six adults experiencing infertility at some point in their lives. In the U.S., more than 13 percent of women in their childbearing years have fertility issues, along with more than 11 percent of their male peers.
Lost in the debate is the question of why couples increasingly need fertility assistance at all.
While multiple factors drive infertility rates — including couples choosing to delay having children while they build their careers, only to find it’s more difficult to conceive at an older age — evidence is building that the introduction of manmade chemicals into the environment has played a role.
Over several decades, research has emerged confirming that exposure to manmade chemicals in the environment accelerates ovarian aging, contributing to infertility and earlier onset of menopause.
Studies suggest exposure to now-ubiquitous endocrine-disrupting chemicals — such as bisphenols and phthalates often found in plastics — may be reducing the number and quality of eggs a woman can produce, along with the number of sperm her potential partners produce to fertilize those eggs. It’s not hard to understand that fewer eggs and fewer sperm translate into fewer opportunities to conceive.
Animal studies provide further evidence that chemicals contribute to the problem. Studies show declines in fertility and shrinking populations among fish, amphibians, reptiles and birds. Unlike humans, animals do not choose to delay parenthood until it’s more financially feasible to raise a family in comfort. Environmental factors, not lifestyle choices, are driving animal fertility declines that parallel the decline in human fertility.
While we cannot reverse ovarian aging, we can take steps to reduce these harms to human and animal fertility and ensure that those eggs, sperm and embryos that are produced can develop and grow in a healthier environment.
And it’s not just fertility that is impacted by these chemicals. The chemical exposures can cause harm to the unborn child during the early phases of embryonic development.
Studies show even low-level fetal exposures to bisphenol-A, the most studied man-made contaminant, raise the risk of producing chromosomally abnormal eggs by as much as 40 percent, which often leads to miscarriage. And exposure to phthalates during early pregnancy produces males with genitals that are not fully masculinized.
These trends can only be slowed by ensuring that hormone-altering chemicals are tested and regulated before they enter the marketplace — and our bodies. We need to monitor chemicals in our air, water, soil, homes, schools and workplaces better to know what we’re exposing ourselves to. We must better understand how manmade chemicals enter our bodies and what happens when they do — not just to us, but to our unborn and not-yet-conceived children.
There’s plenty of evidence to suggest that these chemicals have already done irreparable harm. It is now urgent that we act to fully understand the consequences of what has been unleashed into the environment, and implement policies and regulations to protect ourselves and the offspring of generations to come. Otherwise, one day, there might not be any embryos left to fight about.
Patricia Hunt is a Reagents Professor at the Washington State University School of Molecular Biosciences. Gail S. Prins is the Michael Reese Distinguished Professor and co-director of the Chicago Center for Health and Environment at the University of Illinois, Chicago. Shanna Swan is a professor in the Department of Environmental Health and Climate Science at Icahn school of Medicine at Mount Sinai.