P-721 Exploring the impact of geographical variation: A retrospective study examining semen phenotypes within a cohort of 19,612 men attending a fertility center in the UAE
Authors: Du Plessis S , Omolaoye T , Aslam I , Lakshmanan J 
Published: July 2024

Abstract

Study question
What are the epidemiological trends of semen phenotypes and their association with geographic regions among men seeking fertility treatment in the UAE?

Summary answer
Following covariate adjustment, UAE Nationals attending a fertility center displayed lower incidence of oligozoospermia and higher prevalence of asthenozoospermia and teratozoospermia compared to other nationalities.

What is known already
Conventional semen analysis remains the gold standard for diagnosing and managing male infertility. It is well documented that semen is heterogenous and can be influenced by diverse factors, including but not limited to race, ethnicity, sociocultural background, seasonality, and geographical region. Although higher infertility prevalence has been reported in regions like North Africa and the Middle East, existing estimates rely largely on data from female partners of infertile couples and studies dating back to 1988. This underscores a significant data paucity in the Middle East.

Study design, size, duration
In this retrospective study, the anthropometric data (age, weight, height, body mass index, nationality) and semen parameters (semen volume, semen pH, sperm concentration, total sperm count (TSC), total motility (TM), progressive motility (PM), normal morphology, viability) of 19,612 men (32,664 samples) who attended a fertility center in the UAE between 2011 and 2022 were assessed. Ethical approvals for this study were obtained from appropriate bodies (REC/2022/P27 and MBRU IRB-2021-12).

Participants/materials, setting, methods
Data from patients were categorized into different geographical regions (Sub-Saharan Africa, North Africa, North America, Central America, South America, Asia, Europe, Middle East, and Oceania) based on nationality. Patients were further grouped as MENA (Middle East and North Africa) and non-MENA, while data from UAE Nationals (UAE) were also compared to Other Nationalities (Global). Unadjusted analysis was performed using SPSS. While covariate adjustment and propensity score analyses were performed using R package and STATA.

Main results and the role of chance
All semen parameters, remained within normal WHO reference values when stratifying according to geographical regions, MENA and Non-MENA as well as UAE and Global. Interestingly, MENA displayed a significant reduction in semen volume (p &lt; 0.0001) and sperm concentration (p = 0.017), and an increase in PM (p &lt; 0.00001). Similarly, PM was higher in UAE versus Global.
To address skewed data distribution between UAE and Global, we employed propensity score analysis and logistic regression models, with semen parameters categorized according to WHO lower reference limits.
Following covariate adjustment, all models demonstrated no significant difference in PM and TM between the two subgroups. However, logistic regression indicated a non-significant increase (4%) in the prevalence of asthenozoospermia in UAE compared to Global. Categorical analysis indicated that the Global samples had significantly lower TSC compared to the UAE group (24.6% vs. 26.3%, p&lt;.001). Modelling adjusted for propensity score and UAE Nationality further suggested that UAE were 13% less likely to have lower TSC compared to Global (p&lt;.001). About 58% of UAE samples exhibited teratozoospermia, while it was 56% for Global. After adjusting for confounders, analysis revealed a significantly higher prevalence (12%) of teratozoospermia among UAE compared to Global, with a potential range of 9%-16% in the long term.

Limitations, reasons for caution
A limitation of the current study is data distribution skewness. Of the 32,664 samples from 19,612 patients (113 countries), 21,649 samples are from UAE Nationals. However, logistic regression, propensity score adjustment accounting for Nationality, propensity score matching (1:2 ratio), and inverse probability weighting were applied to mitigate this bias.

Wider implications of the findings
Paucity of data on male fertility in the UAE and MENA region does not allow for accurate estimation of male infertility. Owed to its sample size and statistical robustness, this study provides evidence addressing this gap, offering insights into interpretation of global data on reproductive health.

Trial registration number
not applicable