(251) Temporal Trends of Semen Quality and Fertility Rates Over the Course of a Decade: Data from King County, Washington
Authors: Miller D , Weber A , Loloi J , Reddy R , Ramasamy R 
Published: May 2023

Introduction

A progressive decline in the quality of semen over the past few decades has been reported. The reason for this decline remains controversial. Semen analysis guidelines have become increasingly strict which may account for the decline. Additionally, this decline may be attributable to growing rates of obesity, environmental, and other health issues. However, it remains unknown as to whether this decline is of clinical relevance with an impact on fertility rates.

Objective

To determine if there is a temporal trend in both fertility rates and semen parameters, we assessed semen parameters in a population of healthy male sperm donors and fertility rates for King County, WA over the course of a decade. We hypothesized that there would be both a decrease in semen parameters as well as a decrease in fertility rate due to health, environmental, and social factors.

Methods

Semen parameters from sperm donors at a sperm bank were obtained from 2008 and 2020. To delineate differences over time, semen parameters were assessed from two 3-year periods 2009-2011 and then from 2018-2020. Sperm donations occurred in King County, WA. Donors were from within 50 miles of the donation site. Fertility rates for the same two time periods were calculated for King County, WA using census data from SEER to find number of women aged 15-49 and the number of births were found using CDC Wonder data.

Results

There was a total of 28,576 sperm donor records included in our study. The mean sperm concentration and total motile sperm count for sperm donors declined from 2009-2011 to 2018-2020 respectively by 20.8% and 47.6% (Figure 1). Progressive motility also decreased from an average of 80% in 2009-2011 down to an average of 60% from 2018-2020. The fertility rate for King County, WA was 58 births per 1000 women from 2009-2011 and declined to 49 births per 1000 women in 2018-2020 (Figure 1). Strengths of the study include both report of both sperm count and fertility rate, large sample size and contemporary cohort of semen analyses performed using the latest WHO standards. Limitations of the study include possible inter-observer variability among laboratory technicians performing semen analyses and inability to account for co-morbidities as they are not available in the dataset, and female factors that are associated with birth rates were not accounted for in this study.

Conclusions

There was an overall decrease in the quality of semen parameters over time for donors. Concurrently, we observed a decline in fertility rates for the same county in which the sperm donors were from. While there are certainly confounding variables we cannot account for in determining the association, our results show that both semen parameters and fertility rate have declined within the same geographic area over the same period.

Disclosure

Any of the authors act as a consultant, employee or shareholder of an industry for: Acerus Pharmaceuticals Consultant, Grant Recipient Boston Scientific Consultant, Grant Recipient Coloplast Consultant, Grant Recipient Endo Pharmaceuticals Consultant, Grant Recipient Empower Pharmacy Grant Recipient Nestle Health Consultant Olympus Grant Recipient Hims, Inc Advisory Board