Environmental factors in declining human fertility.
Niels E Skakkebæk1,2,3, Rune Lindahl-Jacobsen4, Hagai Levine5
1Department of Growth and Reproduction, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark. Niels.Erik.Skakkebaek@regionh.dk.
Nature Reviews. Endocrinology
|December 16, 2021
Summary
Declining birth rates and widespread infertility in industrialized nations may be linked to environmental chemical exposures, not just economic factors. Urgent research and regulatory action are needed to address this reproductive health crisis.
Area of Science:
- Reproductive biology and environmental health.
Background:
- Human reproductive health is declining in industrialized regions, evidenced by widespread infertility, poor semen quality, and increased testicular cancer rates.
- Fertility rates have been below population sustainability levels in most industrialized regions since around 1900.
- Existing demographic reports attribute birth declines primarily to economic and behavioral factors.
Purpose of the Study:
- To investigate the extent to which biological factors contribute to the decline in human reproductive health.
- To explore the hypothesis that chemical exposures from fossil fuels are linked to deteriorating reproductive health and declining fertility rates.
- To highlight the need for interdisciplinary research and regulatory action to reverse negative fertility trends.
Main Methods:
- Review and discussion of existing data on reproductive health indicators, including infertility, semen quality, oocyte failure, testicular cancer incidence, and twinning frequency.
- Analysis of trends in conception and abortion rates.
- Correlation of reproductive health trends with potential environmental exposures.
Main Results:
- Significant indicators of declining reproductive health are observed globally, including widespread infertility and increased incidence of testicular cancer in young men.
- Conception rates have deteriorated, contributing to fertility rates below population replacement levels in industrialized regions.
- The study suggests a potential link between reproductive health decline and increased human exposure to chemicals derived from fossil fuels.
Conclusions:
- The decline in human fertility is likely influenced by biological factors, specifically environmental chemical exposures, beyond economic and behavioral influences.
- Addressing the current infertility epidemic requires decisive regulatory action and unconventional, interdisciplinary research.
- Reversing the trend of declining reproductive health is critical for sustaining populations in industrialized regions.
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