Objective

To determine the reproducibility of the World Health Organization Fifth Edition (WHO5) strict grading methodology by comparing the percentage of morphologically normal sperm (PNS) recorded by the core laboratory with results obtained at the fertility centers participating in a multisite clinical trial.

Design

Secondary cohort analysis of data from the Males, Antioxidants, and Infertility trial.

Setting

Fertility centers.

Patients

Semen values of 171 men participating in a multicenter, double-blind, randomized, placebo-controlled trial evaluating the effect of antioxidants on male fertility.

Interventions

Not applicable.

Main outcome measures

Strict morphology expressed as PNS as determined at each fertility center and the core central laboratory for the same semen sample.

Results

No correlation was found in the PNS values for the same semen sample between the core laboratory and fertility center laboratories either as a group or by individual site. Interobserver agreement was similarly low (κ = 0.05 and 0.15) between the core and fertility laboratories as a group for strict morphology, categorized by the WHO5 lower reference limits of 4% and 0, respectively. Moderate agreement was found between the core and 2 individual fertility laboratories for the cutoff value of 0 (κ = 0.42 and 0.57). The remainder of the comparisons demonstrated poor to fair agreement.

Conclusions

Strict morphology grading using the WHO5 methodology demonstrated overall poor reproducibility among a cohort of experienced fertility laboratories. This lack of correlation and agreement in the PNS values calls into question the reproducibility, and thereby the potential applicability, of sperm strict morphology testing.

Objective

To examine the factors associated with increased deoxyribonucleic acid fragmentation index (DFI), evaluate the pregnancy outcomes of men with increased DFI, and compare three independent DFI assays.

Design

Secondary analysis.

Setting

Nine US-based fertility centers.

Patients

Infertile men (N = 147) with sperm concentration ≤15 × 10⁶/mL, motility ≤40%, or normal morphology ≤4% were enrolled. The female partners were ovulatory, ≤40 years old, and had documented tubal patency.

Interventions

At a baseline visit, the men provided a semen sample. The couples attempted conception without assistance for 3 months and with ovarian stimulation and intrauterine insemination in the subsequent 3 months.

Main outcome measures

The DFI was analyzed using the sperm chromatin structure assay (SCSA) with increased DFI defined as >30%. The predictors of increased DFI were determined by a multivariable linear regression model. The pregnancy outcomes were compared using the χ² test. The independent DFI assays (SCSA, deoxynucleotidyl transferase-mediated dUTP nick end labeling, and Comet) were compared with Pearson and Spearman correlations.

Results

The 19% of men with increased DFI were older (36.0 vs. 33.0 years) and had lower total sperm motility (38.2% ± 20.5% vs. 45.2% ± 15.6%). Increased male age was found to be a significant predictor of DFI (0.75, 95% confidence interval [0.06, 1.45]). Increased DFI was not associated with conception or live birth. There was a modest correlation of the deoxynucleotidyl transferase-mediated dUTP nick end labeling assay with the SCSA (r = 0.34) and Comet assay (r = 0.19).

Conclusions

Older age was associated with increased DFI among infertile men. The DFI assays were only weakly correlated, indicating a standard definition of DFI is needed to truly interrogate how sperm deoxyribonucleic acid fragmentation impacts male fertility.