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Teratozoospermia is one of the important factors contributing to male infertility, and its pathogenesis is not yet clear. Recent years have witnessed some progress in the researches on sperm morphology, and some genes have been confirmed to be correlated with spermatogenesis. Aiming to provide some evidence for the pathogenesis of teratozoospermia, this paper reviews the relevant literature in the past five years addressing such special teratozoospermia as globozoospermia, nuclear vacuoles, decapitated spermatozoa, excessive residual cytoplasm, dysplasia of the fibrous sheath, and primary ciliary dyskinesia, and elaborates on the molecular genetic mechanisms of DPY19L2, AR, PRM1, GBA2, PCI, CREM, TH2A, TH2B, ODF1, Cntrob, OAZ-t, HOOK1, SPEM1, GAT1, PRSS21, 15-LOX, Sptrx, AKAP3, AKAP4, DNAI1, DNAH5, RSPH4A, TXNDC3, CCDC39, LRRC6, LRRC50, KTU and so on. Meanwhile, this review also presents an overview on the latest advances in assisted reproductive technology and its outcomes in the treatment of teratozoospermia patients in order to provide a theoretical basis for the diagnosis and treatment of male infertility.

The incidence of infertility is on the rise worldwide. Statistically, infertility affects approximately 15% of couples and 50% of males, which can be attributed to the decreased sperm quantity and quality and consequently male eugenesis induced by such esoteric factors as quickened pace of life, polluted environment, unhealthy behaviors, and so on. With the establishment and development of the free radical theory, active oxygen-mediated oxidative stress has been found to play a significant role in the pathogenesis of male infertility. This review presents an overview of the esoteric factors responsible for sperm oxidative stress.

Many factors are responsible for sperm DNA damage, which may lead to fertilization failure and embryo maldevelopment. At present, sperm DNA damage can be detected by more and more methods, which are considered to be superior to the conventional measures. There are some clinical indications for tests of sperm DNA damage in IVF/ICSI, but additional studies are still needed to fully define the clinical value of testing sperm DNA damage.

Sperm cryopreservation has revolutionized the field of assisted reproduction. However, it causes cryodamage to the structure and function of spermatozoa during the freezing-thawing process. Optimization of sperm cryopreservation is necessary for the preservation of male fertility. Cryodamage can be reduced effectively by such methods as improvement of semen quality before freezing, spermatozoal selection, addition of optimal cryoprotectants and application of appropriate thawing techniques. Recent studies focus on cryobiology, improvement of freezing-thawing methods, especially for poor quality semen, and evaluation criteria for post-thaw spermatozoa.

This article reviews the recent literature on sperm morphology and attempts to illuminate the important value of sperm morphology for evaluating man fertility, with a survey of the present status of sperm morphology analysis techniques and the relationship between sperm morphology and sperm function tests. Sperm morphology analysis, although its techniques need to be further improved, is proved of great value for its significant correlation with sperm function and as a predictor in assisted reproduction.

Ca2+ is an important positive ion in the living body. Recently, there have been quite a few reports about the function of Ca2+ in sperm. Calcium is considered as a regulator of sperm motility, a participant in sperm capacitation, and an essential second messenger for acrosome reaction. This paper reviews the relationship of Ca2+ with sperm function.

Leukocytospermia is a most common cause of male infertility, but the distribution, origin and role of leukocytes in semen are still controversial. Some reports on leukocytospermia have indicated its negative effects on semen parameters and even in vitro fertilization (IVF). Recent literature has made it clear that the most deleterious effect of leukocytospermia is that the increased reactive oxygen species (ROS) may cause sperm damage, leading to significantly increased male infertility. The treatment and prevention of leukocytospermia have been proven of help for improving semen parameters.

Objective: To evaluate the relationship between sperm motility parameters and sperm morphology., Methods: Seven hundred and eighty-three semen samples were tested. Sperm motility parameters were analyzed by computer-aided sperm analysis (CASA) , and sperm morphology assessed by automated sperm morphology analyzer (ASMA). The cases were classified based on the World Health Organization criteria. Morphologically 241 of the samples were normal and the other 542 abnormal., Results: VCL, WOB, VAP of the morphologically abnormal group were significantly higher than those of the normal group (P < 0.05, P < 0.001), while MAD, LIN, STR of the abnormal group were significantly lower (P < 0.05, P < 0.001). There were significant positive correlations between the morphologically normal sperm rates and MAD, LIN, WOB, STR, and a significant negative correlation between the morphologically normal sperm rate and ALH., Conclusion: Morphological abnormality of sperm is often accompanied with weak motility, which is probably attributed more to some factors that coact on both sperm motility and morphology than to the influence of sperm morphological abnormality on sperm motility.

Objective: To investigate effects of cigarette, alcohol consumption and sauna on sperm morphology., Methods: 602 cases of male infertility were selected from our case database, who were divided into three subgroups: smoking (243) , drinking(224), sauna(135) and those without any of the above habits were taken as the corresponding controls. The sperm morphology were analyzed by automated sperm morphology analyzer(ASMA). A questionnaire was voluntarily filled out by patients in order to investigate cigarette, alcohol consumption and sauna frequency., Results: The normal morphologic sperm rates in cigarette, alcohol consumption and sauna groups were lower than those in the corresponding control groups, respectively(P <0.05, P <0.001). Percentages of irregularity head sperm were higher than those in normal controls, respectively(P <0.05)., Conclusion: Cigarette, alcohol consumption and sauna could affect sperm morphology, especially caused increasing of irregularity head sperm.

Many factors can result in male infertility, and a number of studies have indicated that reproductive difficulties are associated intimately with cytogenetic abnormalities. This article reviews studies on sperm chromosomes in infertile men and discusses the relationship between sperm chromosome abnormality and male infertility.

Objectives: To study the effect of antisperm antibody(AsAb) on human sperm acrosin activity., Methods: AsAb and sperm acrosin activity were measured and analyzed in 3,432 infertile men and 65 fertile volunteers., Results: AsAb positive rate was 10.20% in 3,432 case of male infertility, and 9.37% in 2,882 infertile males who received tests of sperm acrosin activity. Acrosin activity of infertility cases were lower than those of fertile cases(P < 0.001). The comparison between AsAb positive group and AsAb negative group infertility cases showed no significant differences of acrosin activity (P > 0.05). Between normal acrosin activity group and abnormal acrosin activity group, there was no significant difference of AsAb positive rate (P > 0.05)., Conclusions: Antisperm antibody could not affect acrosin activity.