Sperm DNA integrity assessment in prediction of assisted reproduction technology outcome

Do sperm DNA integrity tests predict pregnancy with in vitro fertilization?

OBJECTIVE

To evaluate the predictive value of sperm DNA integrity tests for pregnancy from in vitro fertilization treatment.

DESIGN

Systematic review and meta-analysis.

SETTING

Studies from infertility centers.

PATIENT(S)

Infertile couples undergoing in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment.

INTERVENTION(S)

Sperm DNA integrity tests before IVF and ICSI cycles.

MAIN OUTCOME MEASURE(S)

Diagnostic test properties for sperm DNA integrity tests with reference to pregnancy after IVF or ICSI treatment.

RESULT(S)

Among 22 relevant studies, 2 x 2 tables were constructed from 13 studies involving 18 estimates of the diagnostic test properties of sperm DNA integrity tests in 2162 cycles of treatment. The sum of sensitivity and specificity ranged from 0.83 to 1.59. In six of 18 estimates abnormal DNA integrity was associated with a higher than expected pregnancy rate. The summary diagnostic odds ratio was 1.44 (95% CI, 1.03, 2.03), but the summary likelihood ratios (LR) were not predictive of pregnancy outcome (LR+ = 1.23; 95% CI, 0.98, 1.54; LR- = 0.81; 95% CI, 0.67, 0.98). Neither sperm chromatin structure assay nor terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling assay tests were more predictive of pregnancy outcome after IVF/ICSI, and DNA integrity testing was not more predictive for IVF than ICSI.

CONCLUSION(S)

The small but statistically significant association between sperm DNA integrity test results and pregnancy in IVF and ICSI cycles is not strong enough to provide a clinical indication for routine use of these tests in infertility evaluation of men. It is possible that yet to be determined subgroups of infertile couples may benefit from sperm DNA integrity testing.

Deoxyribonucleic acid-damaged sperm in cryopreserved-thawed specimens from cancer patients and healthy men

A similarity was found between the percentage of thawed, DNA-damaged spermatozoa in cancer patients and that in candidates to become sperm bank donors who had low sperm cryofreezability. Both groups were significantly different from the sperm bank donor group. It is suggested that the higher rate of DNA fragmentation in sperm from cancer patients compared with sperm bank donors is apparently a result of selecting donors by the level of sperm cryofreezability (i.e., high), rather than a direct effect of an existing malignancy.

Is sperm evaluation useful in predicting human fertility?

Traditionally, the diagnosis of male infertility has relied upon microscopic assessment and biochemical assays to determine human semen quality. The conventional parameters given most importance have been the concentration, motility, and morphology of sperm in the ejaculate. Most laboratories also include ‘sperm suitability’ tests where the subpopulations of sperm more likely to finish the marathon journey to the oocyte are separated by density centrifugation. These tests are essential to provide the fundamental information on which clinicians base their initial diagnosis. However, none of these parameters addresses sperm function and their clinical value in predicting fertility is questionable. The advent of intracytoplasmic sperm injection (ICSI) has further reduced the significance and perceived need for sperm quality tests since ICSI requires only one sperm, not subject to classic, or indeed any, tests for the procedure to be successful. Over the past decade, a number of laboratory tests have been developed to determine properties of sperm function. These include quantitative sperm motion parameters, capacitation, basal and induced acrosome reactions, sperm–zona pellucida interactions and nuclear and mitochondrial sperm DNA but few have been adopted into routine clinical use. International collaborations should be initiated to develop clinically relevant molecular and functional tests with agreed protocols and clinical thresholds as a matter of urgency.

DNA damage of human spermatozoa in assisted reproduction: origins, diagnosis, impacts and safety

Sperm DNA contributes half the offspring's genomic material and abnormal DNA can lead to derangements in the reproductive process. Normal sperm genetic material is required for successful fertilization, as well as for further embryo and fetal development that will result in a healthy child. Thus, the damage to sperm DNA is critical in assisted reproductive techniques which are increasingly used to treat infertile couples. There has been improving data about the effects of human sperm DNA damage or fragmentation. As well, increasing knowledge concerning the effects of DNA damage on embryo and fetal development has been attained. This review aims to summarize the present knowledge on the impact of human sperm cell DNA damage on male infertility and outcome in the context of safety.