Sperm Morphology: History, Challenges, and Impact on Natural and Assisted Fertility.
PURPOSE OF REVIEWThe classification of morphologically normal sperm has been progressively redefined. Concurrently, our understanding of the significance of sperm morphology in relation to male factor infertility has evolved. In this review, we will discuss the evolution of sperm morphology assessment and factors that contribute to its measurement variability. We will examine the impact of sperm morphology on natural pregnancy, IUI, IVF, and ICSI outcomes.
RECENT FINDINGSThere is a lack of consensus on sperm morphology classification, technique, and inter-observer grading variability. Current evidence suggests sperm morphology has low predictive value for pregnancy success, for both natural and assisted reproduction. Additionally, the threshold for what is considered an adequate percentage of morphologically normal sperm has changed over time. These variables have called into question the relevance of this variable in predicting fertility outcomes. Our understanding of the impact of sperm morphology on reproductive outcomes continues to evolve and seems to play less of a role than initially thought.
Division of Reproductive Endocrinology, University of Southern California, 2020 Zonal Avenue, IRD 534, Los Angeles, CA, 90033, USA. Rachel.firstname.lastname@example.org.
Institute of Urology, University of Southern California, 1441 Eastlake Avenue, Suite 7416, Los Angeles, CA, 90089, USA.
Pub Type(s)Journal Article