Abstract
This integrative review aimed to explore the impact of the spread of coronavirus disease 2019 (COVID-19) on fertility to establish foundational knowledge and guide future epidemiological studies. The PubMed and Central Journal of Medicine databases were searched, yielding 80 relevant articles published between 2019 and 2021. Of these, 14 were published in Japanese and 66 in English. None of the Japanese studies met the inclusion criteria. Fourteen English-language studies, all of which were retrieved from PubMed, were included in the final analysis. No relevant literature was found in the Central Journal of Medicine. The keywords used were COVID-19, fertility, and demographics. COVID-19 led to an increase in unplanned pregnancies and abortions in developing countries. Fever associated with the infection was suggested to have reduced sperm concentration and motility, and the spread of the infection caused young couples to delay childbearing, potentially decreasing fertility. Conversely, relatively older couples showed fewer changes in their childbearing plans, indicating that COVID-19 had both positive and negative effects on fertility. Physical, psychological, and economic factors as well as sex, age, and cultural background exerted complex effects on fertility. Herein, the impact of social crises on fertility rates has been discussed in the context of the recent COVID-19 pandemic. Analysing the effects of this pandemic on fertility rates is crucial for understanding future demographic trends and national strengths. This study provides valuable data for future research in this field.