O-207 Which infertile patients mostly deserve to have a sperm DNA fragmentation index done? Findings from a cross-sectional study

Study question

Current scientific guidelines do not clearly suggest which patients would benefit the most from a sperm DNA fragmentation (SDF) test.

Summary answer

We aimed to investigate potential predictive factors for altered SDF in a homogenous cohort of white-European men presenting for primary couple’s infertility.

What is known already

High SDF has been associated with reduced fertilization rates, reduced chances of natural conception and an increased risk of early pregnancy loss.

Study design, size, duration

Data from 478 consecutive men with normal or altered SDF were analysed. Infertility was defined according to the WHO criteria. Semen analysis, SDF (according to SCSA) and serum hormones were measured in every patient. Health significant comorbidities were scored with the Charlson Comorbidity Index (CCI). Altered SDF was considered with a threshold of > 30%.

Participants/materials, setting, methods

Descriptive statistics compared the overall characteristics of patients with normal SDF and altered SDF. Logistic regression analysis tested potential predictors of altered SDF. ROC curve was used to test the accuracy of the model in predicting SDF alteration

Main results and the role of chance

Of 478 patients, 253 (57.7%) had altered SDF. Median (IQR) age and BMI of the whole cohort were 38 (35-42) years and 25.1 (23.3-27.1) kg/m2 respectively. Patients with altered SDF were older (median (IQR) age: 39 (36-43) vs. 37 (34-38) years, p < 0.0001), had lower sperm concentration (5 (1.1–18) vs. 17 x106/mL (6–38.8), p < 0.0001), testicular volume (15.1 (12 –20) vs. 16.8 (12 – 25) Prader, p = 0.0005), and total motile sperm count (TMSC) (1.8 (0.21–10.71) vs. 11.8x106 (2–37.26), p < 0.0001). Conversely, men with altered SDF had higher FSH (6.1 (3.85–9.7) vs. 4.8 (3.85 – 7.9) mIU/mL, p < 0.0001) and prolactin levels (9.8 (7.43–14.04) vs. 8.3 (6.6–11.3) pg/mL, p = 0.0004) than those with normal SDF. At multivariable logistic regression analysis, patients’ age >35 years (OR: 2.45, p = 0.0009), FSH > 8.0 mIU/mL (OR: 2.23, p < 0.0001) and lower TMSC (OR: 2.04, p = 0.002) were identified as indipendent predictors of altered SDF, after adjusting for testicular volume and CCI≥1. ROC curve (Figure 1) revealed that the model has a good predictive ability to identify patients with SDF alteration (AUC: 0.72, 95%CI: 0.67 - 0.77).

Limitations, reasons for caution

It is a retrospective analysis at a single, tertiary-referral academic centre, thus raising the possibility of selection biases. In spite of this, all patients have been consistently analysed over time with a rigorous follow-up, thus limiting potential heterogeneity in terms of data reporting

Wider implications of the findings

Primary infertile men older than 35 years, with high serum FSH and low TMSC at baseline are the ones who mostly deserve a SDF test over their diagnostic work-up and that would potentially benefit the most of certain treatments to improve SDF value, thus increasing chances of conceiving.

Trial registration number

Not applicable

P–027 Does air pollution impact on semen parameters? Findings from a real-life cross-sectional study in white-European infertile men

Study question

We aimed to investigate the association between air pollutants levels and semen parameters in a cohort of white-European men seeking medical attention for couple’s infertility.

Summary answer

We found that Pm10, Pm 2.5, and NO2 levels were negatively associated with sperm morphology.

What is known already

Air pollutants levels have been monitored closely for environmental and research issues in industrialized countries.

Study design, size, duration

Data from 156 infertile men consecutively assessed between 01/2019 and 12/2020 were analysed.

Participants/materials, setting, methods

Semen analyses were based on 2010 WHO reference criteria. We analysed the annual average level of the main markers of air pollution (Pm10, Pm2.5, and NO2) between 2014–2018 (Legambiente, 2020, Annual dossier series on air quality in Italy) relative to patients’ addresses of the last 5 years. Health-significant comorbidities were scored with the Charlson Comorbidity Index (CCI). Descriptive statistics and linear regression analyses were used to test the association between air pollutants and semen parameters.

Main results and the role of chance

Overall, median (IQR) age and BMI were 37 (33–41) years and 25.1 (23.4–27.3) kg/m2, respectively. A CCI≥1 was found in 12 (7.7%) men, and 47 (30.1%) participants were smokers. As for sperm parameters, semen volume, sperm concentration, sperm progressive motility and normal sperm morphology were 3 (2–4) ml, 18 (5–45.5) x106/ml, 32 (22–45)% and 2 (1–3)%, respectively. Pm10 was negatively associated with sperm morphology (ß: –0.580, p = 0.001). Furthermore, Pm10 was found to be an independent predictor for sperm morphology worsening (ß: –0.729, p = 0.006) (Fig.1A), after adjusting for age, BMI, CCI and smoking status. Similarly, Pm2.5 levels were negatively associated with sperm morphology (ß: –0.595, p = 0.009) (Fig.1B). After adjusting for the same variables, the association between Pm2 and sperm morphology remained significant (ß: –0.724, p = 0.015) (Fig.1C). NO2 levels were found to be associated with sperm morphology worsening after adjusting for age, BMI, CCI, and smoking status (ß: –0.471, p = 0.006).

Limitations, reasons for caution

It is a retrospective analysis at a single, tertiary-referral academic centre, thus raising the possibility of selection biases. Moreover, markers of air pollutions divided by residence may not completely evaluated the single patient exposure.

Wider implications of the findings: In this cross-sectional study we found that Pm10, Pm 2.5, and NO2 levels were negatively associated with sperm morphology, while they were not consistently associated with an increased risk of other abnormal sperm parameters in infertile men. Further studies are needed to characterize air pollution effects on sperm parameters.

Trial registration number

Not applicable