Climate change, human fertility, and the health of future generations: a call for action

Climate change is a global issue that has been on the headlines for quite a while with major threats to human existence through a variety of mechanisms. Fertility rates are decreasing with dire social and economic consequences as women delay childbearing, and pollution, obesity, and diets rich in endocrine disruptors among other factors compromise reproductive health even further (Giudice et al. 2021; Segal and Giudice 2022). As maternal health deteriorates, so does the intrauterine environment and thus embryo/fetus well-being. Periconceptional maternal health is of paramount importance to the growing individual as the intrauterine environment may define health and disease (Oostingh et al. 2019). However, what does climate change have to do with human fertility?

There is hardly any dispute when one considers the ominous effects of climate change on the economy, agriculture, biodiversity, and human health in general, but the possible effects on fertility have not been widely publicized until recently (Walsh et al. 2019). In addition to the economical and environmental effects that may influence people’s decisions to have a child, biological effects on the male and female reproductive systems have been described (van Heerwaarden and Sgrò 2021; Walsh et al. 2019). In an effort to call attention to the matter, the American Society for Reproductive Medicine (ASRM), the American College of Obstetricians and Gynecologists (ACOG), and the International Federation of Gynecology and Obstetrics (FIGO) published position statements emphasizing the climate-related hazards to women’s health and their children as well as pointing out the vital role obstetricians and gynecologists should play in this setting (Giudice et al. 2021; Martin et al. 2022; The American College of Obstetricians and Gynecologists 2022).

Experimental studies using Drosophila alert that life close to the critical thermal limits increases the chances of extinction as organisms have limited ability to adapt as temperatures rise, with male infertility occurring at sublethal temperatures (van Heerwaarden and Sgrò 2021). Acute changes in maternal temperature leading to cold and heat stress have been associated with increased risks of stillbirth, with higher risks as the intensity and duration of the thermal stress episodes rose (Nyadanu et al. 2022). Other obstetrical complications have been associated with climate changes such as miscarriage and preterm birth (Giudice et al. 2021). Therefore, the role of environmental factors in human fertility can no longer be ignored.

The ever-increasing need for medically assisted reproduction worldwide, mainly in industrialized nations, favors the idea that chemicals and pollutants do affect the gametes and reproductive health as fertility rates dwindle over the years, reaching incredibly low levels in recent years. (Skakkebæk et al. 2022). This steep drop in birth rates poses a tremendous threat as the population rapidly ages, putting the survival of the current social security systems at stake according to a document published by the International Monetary Fund (International Monetary Fund 2022).

To complicate matters further, climate change may affect the well-being of future generations as it compromises both maternal and paternal health and thus offspring health. It is very unfortunate that the most vulnerable and neglected populations are the ones that take the highest toll mainly in low-resource settings, which should further deepen the socio-economic gap and inequality (Giudice et al. 2021). Poor maternal and paternal preconceptional health may further compromise fertility rates in future generations (Oostingh et al. 2019; van Heerwaarden et al., 2021). Unfortunately, public health policies regarding preconceptional health are scarce and heterogeneous (Carneiro et al. 2021; Shawe et al. 2015).

Regrettably, no feasible solution is on the horizon to reverse the current trends despite all the climate conferences and meetings. Reproductive health must be included in the climate change agenda. The ASRM, ACOG, and FIGO efforts should be praised, but we need to engage other medical societies, universities, policymakers, governments, and people all over the world. Collaborative research among countries is necessary so as to understand the effects of global warming on human reproduction, identify strategies to increase awareness, and counteract the worse effects as well as develop and implement evidence-based guidelines for managing the fertility journey in this setting if we are to avoid such a dystopic reality.