P–049 The presence of double heads is associated with increased frequency of the other sperm abnormalities

Abstract

Abstract Study question Is there an association between the presence of spermatozoa with double heads and the other sperm abnormalities in human semen? Summary answer Patients with double-headed spermatozoa had a significantly increased percentage of morphological abnormalities (head, midpiece and tail defects). What is known already The morphological evaluation of spermatozoa has a prognostic value for successful IVF procedure. It has been proven that certain morphological defects have a negative impact on fertilization, embryo quality, and pregnancy outcome in in-vitro fertilization cycles. Sperm abnormalities, such as double head, double tail and thin midpiece are rarely observed. However, their effect on the other sperm defects has not been well studied yet. The aim of this study was to examine the effect of the presence of double-headed spermatozoa on the frequency of occurrence of the other sperm defects. Study design, size, duration This retrospective study includes 2140 men aged between 18 and 73 years, with a mean of 36 years. It was conducted at Nadezhda Women’s Health Hospital, Bulgaria between October 2015 and August 2020. A comparative analysis was performed between semen samples with and without double-headed spermatozoa and the other sperm abnormalities, as well as the percentage of morphologically normal forms. Participants/materials, setting, methods Morphological analysis was performed according to the Kruger’s strict criteria. Totally 23 types of abnormalities were determined: head defects (small, large, amorphous, elongated, round, pear-shaped, double, acephalic, detached head, small and large acrosomal areas and spermatozoa without acrosome), midpiece defects (thick, bent, asymmetric, thin midpiece and cytoplasmic droplets), tail defects (stumped, coiled and double tail), acrosomal vacuoles, nuclear vacuoles and multiple defects. Statistics: Mann-Whitney U-test and T-test; P ≤ 0.05. Main results and the role of chance Presence of double-headed spermatozoa was observed in 12.62% (270/2140) of the studied samples. In these patients the frequency of occurrence of double-headed spermatozoa ranged between 1% and 29% with a mean of 0.41%±1.71%. Men with double-headed spermatozoa had significantly higher percentage of spermatozoa with small heads (24.51%±22.65%, P = 0.04), round heads (11.69%±10.13%, P < 0.01), nuclear vacuoles (10.64%±5.25%, P < 0.01), sperm without acrosome (9.76%±8.61%, P = 0.05), asymmetric midpiece (4.73%±3.96%, P < 0.05), bent midpiece (8.9%±7.22%, P < 0.01), thin midpiece (2.13%±4.44%, P < 0.01), double tail (1.78%±0.8%, P < 0.01), detached head (1.98%±1.42%, P < 0.01), stumped tail (6.03%±5.19%, P = 0.02), and cytoplasmic droplets (8.86%±5.02%, P < 0.01) compared to the patients without double-headed spermatozoa. Moreover, the percentage of sperm with multiple defects in the double-headed group was significantly higher (35.53%±29.91%, P < 0.01), while the percentage of normal forms was significantly lower (2.93%±3.64%, P < 0.01) compared to the patients without double heads. Limitations, reasons for caution In this study unequal sample sized groups were compared. We also need to investigate whether the obtained results will be confirmed in patients with certain pathological states, such as oligozoospermia, teratozoospermia, and asthenozoospermia. Wider implications of the findings: The present study revealed that the presence of double-headed spermatozoa in the ejaculate is related to an increased frequency of the other semen abnormalities. The double-headed spermatozoa could be used as an indicator for the total morphological quality of human spermatozoa Trial registration number Not applicable