A Follow-Up Expanded Study of the Correlation of Sperm Velocity in Seminal Plasma and Offspring Gender

Abstract

A preliminary study reported finding higher sperm velocity in seminal plasma in males of partners that conceived female offsprings. The null hypothesis was that sperm velocity was not related to the offspring gender. The objectives were: (a) to expand the previous study, and (b) to correlate offspring gender results with motility parameters determined through the computer-aided sperm analyzer (CASA) system. In combined fresh and frozen cycles (N = 187), sperm from cases with all female offsprings displayed higher curvilinear (48 +/- 1.0 mu/sec versus male 46 +/- 1.0, P < 0.05) and average path velocities (36 +/- 0.7 mu/sec versus male 34 +/- 0.7, P < 0.01). A criteria of less than 30 mu/sec or over 41 mu/sec average path velocity predicted 73 or 72% of the male or female offspring cases, respectively. A curvilinear velocity of less than 49 mu/sec or over 55 mu/sec predicted 58 or 59 % of the male or female offspring cases, respectively. Semen viscosity reflected in sperm velocity was linked to predominantly male or female sperm populations. Paracrine signals from the gender-skewed sperm precursor populations controlling viscosity merit further exploration.

Human semen quality and the secondary sex ratio

“…], 44.2 ± 1.8 μm s −1 vs 49.9 ± 2.7 μm s −1 ) and average path velocities (mean ± s.e.m., 32.4 ± 1.2 μm s −1 vs 36.3 ± 1.7 μm s −1 ) in seminal plasma than did men with female offspring 40. A follow-up expanded study of 187 men corroborated earlier findings on curvilinear and average path velocities in seminal plasma and offspring sex 41. Although not directly tested for semen quality, the effect of male fertility on the SSR has been evaluated in relation to TTP,304243 resulting in equivocal findings.…”

“…As derived from the most extensive evaluation of semen quality parameters in relation to the SSR to date, comparison of our findings with prior research focusing on the association between semen quality and the SSR requires caution, in that much of the past research has relied on men seeking infertility evaluation or treatment, and whose semen quality may differ from fertile men 394041. A Danish study assessed only three semen parameters (sperm concentration, motility, and % morphologically abnormal spermatozoa) that were dichotomized for analysis with the SSR, and observed no associations 39.…”

“…Men with male offspring had slower sperm in seminal plasma, in terms of curvilinear and average path velocities, in comparison with men with female offspring. These findings on curvilinear and average path velocities in seminal plasma and offspring sex were confirmed in an expanded study of 187 men 41. In contrast, although not directly tested for the SSR, in a study of 500 men attending an andrology laboratory in the United Kingdom evaluating sibling sex composition relative to CASA sperm motility measures, men with female-biased siblings had significantly slower sperm than men from male-biased siblings 58.…”

“…Also of note is that the results were generated from single semen analysis that had been conducted before or after having one or more children, preventing the authors from being able to speak to semen quality around time of conception 39. In studies evaluating sperm motility relative to SSR, sperm in seminal plasma rather than ejaculated sperm were assessed in men undergoing ART 4041. Prior research on the association between semen quality and sperm Y:X chromosome ratio may, in part, explain the effect of semen quality on the SSR, given that the SSR is affected by not only sperm Y:X chromosome ratio but also other factors, such as sperm selection within the female reproductive tract and differential implantation and survival rates of embryos 465960…”

Variation among Beef Bulls in the Ratio of X- to Y-Chromosome Bearing Spermatozoa

“…However, swim-up of human sperm for intervals ranging from 15 to 150 min failed to alter the ratio of X-to Y-bearing sperm [16]. Furthermore, analysis of live births after assisted reproductive procedures indicate that sperm from male patients that sired male offspring actually had slower curvilinear and average path velocities than patients siring female offspring [17] [18].…”