Temperature, Climate Change, and Fertility

Abstract

This chapter reviews the empirical literature on the impacts of temperature and climate change on human pregnancies. The focus is on the quasi-experimental studies that use panel data, apply a fixed effect approach, and exploit the random year-to-year fluctuation in temperature. The insights that emerge from the review highlight that exposure to heat in the pre-conception period has detrimental impacts on fertility. In addition, heat during pregnancy increases pregnancy losses, leads to a reduction in gestational length, and lowers birth weight. Despite the growing empirical evidence on the subject, understanding the relationship between temperature and pregnancy-related outcomes is far from perfect. Importantly, the potential impacts of climate change are rarely quantified. The chapter outlines directions for future research.

A systematic map of studies testing the relationship between temperature and animal reproduction

“…For example, exposure to high temperatures can disrupt both the ability of individuals to produce any viable eggs or sperm (fertility), and the number of eggs or offspring produced by fertile individuals (fecundity) (Schou et al., 2021; Walsh et al., 2019). Reproductive impairment due to heat stress is taxonomically widespread, being seen for example in corals (Paxton et al., 2016), insects (David et al., 2005), fish (Breckels & Neff, 2013), livestock (De Rensis et al., 2017; Peña et al., 2019) and humans (Hajdu & Hajdu, 2022; Hoang‐Thi et al., 2022). Further, the mechanisms leading to reproductive impairment are highly variable, because fertility and fecundity are emergent products of many physiological, developmental and behavioural processes (Walsh et al., 2019).…”

“…Further, the mechanisms leading to reproductive impairment are highly variable, because fertility and fecundity are emergent products of many physiological, developmental and behavioural processes (Walsh et al., 2019). For example, reproductive impairment can be due to disrupted gonad development (Delorme & Sewell, 2016; McBride et al., 1997), reduced sperm function (Breckels & Neff, 2013; Peña et al., 2019; Pérez‐Crespo et al., 2008; Vasudeva et al., 2014), reduced fertilisation and pregnancy rates (De Rensis et al., 2017; Hajdu & Hajdu, 2022), or a reduction in the resources that can be invested into gametes or offspring (Dahlke et al., 2020). While both male and female reproduction can be affected by heat stress, sperm production appears to be particularly sensitive (David et al., 2005; Hansen, 2009; Sales et al., 2018; Schou et al., 2021; Walsh et al., 2019).…”

Temperature and Fertility: Evidence from Spanish Register Data

“…A vast body of literature has investigated the impact of climate change and extreme temperatures on various population outcomes, including mortality (Carleton et al, 2020;Conte Keivabu, 2022;Stafoggia et al, 2006;Masiero et al, 2022), infant health (Chen et al, 2020;Conte Keivabu & Cozzani, 2022;Le & Nguyen, 2021), adult health (Bai et al, 2014;Barreca & Shimshack, 2012), income (Isen et al, 2017), educational attainment (Randell & Gray, 2019;Wilde et al, 2017), and migration (Hoffmann et al, 2021). Surprisingly, there has been far less attention given to the impact of climate change on fertility, with only a handful of studies conducted so far (Hajdu & Hajdu, 2020;Grace, 2017). Specifically, two studies were conducted in the US (Barreca et al, 2018;Lam & Miron, 1996), one in South Korea (Cho, 2020), one in Hungary (Hajdu & Hajdu, 2022), and one that pooled together data from sub-Saharan Africa (Thiede et al, 2022).…”