Semen quality of young adult ICSI offspring: the first results

STUDY QUESTION What is the semen quality of young adult men who were conceived 18-22 years ago by ICSI for male infertility? SUMMARY ANSWER In this cohort of 54 young adult ICSI men, median sperm concentration, total sperm count and total motile sperm count were significantly lower than in spontaneously conceived peers. WHAT IS KNOWN ALREADY The oldest ICSI offspring cohort worldwide has recently reached adulthood. Hence, their reproductive health can now be investigated. Since these children were conceived by ICSI because of severe male-factor infertility, there is reasonable concern that male offspring have inherited the deficient spermatogenesis from their fathers. Previously normal pubertal development and adequate Sertoli and Leydig cell function have been described in pubertal ICSI boys; however, no information on their sperm quality is currently available. STUDY DESIGN, SIZE, DURATION This study was conducted at UZ Brussel between March 2013 and April 2016 and is part of a large follow-up project focussing on reproductive and metabolic health of young adults, between 18 and 22 years and conceived after ICSI with ejaculated sperm. Results of both a physical examination and semen analysis were compared between young ICSI men being part of a longitudinally followed cohort and spontaneously conceived controls who were recruited cross-sectionally. PARTICIPANTS/MATERIALS, SETTING, METHOD Results of a single semen sample in 54 young adult ICSI men and 57 spontaneously conceived men are reported. All young adults were individually assessed, and the results of their physical examination were completed by questionnaires. Data were analysed by multiple linear and logistic regression, adjusted for covariates. In addition, semen parameters of the ICSI fathers dating back from their ICSI treatment application were analysed for correlations. MAIN RESULTS AND THE ROLE OF CHANCE Young ICSI adults had a lower median sperm concentration (17.7 million/ml), lower median total sperm count (31.9 million) and lower median total motile sperm count (12.7 million) in comparison to spontaneously conceived peers (37.0 million/ml; 86.8 million; 38.6 million, respectively). The median percentage progressive and total motility, median percentage normal morphology and median semen volume were not significantly different between these groups. After adjustment for confounders (age, BMI, genital malformations, time from ejaculation to analysis, abstinence period), the statistically significant differences between ICSI men and spontaneously conceived peers remained: an almost doubled sperm concentration in spontaneously conceived peers in comparison to ICSI men (ratio 1.9, 95% CI 1.13.2) and a two-fold lower total sperm count (ratio 2.3, 95% CI 1.34.1) and total motile count (ratio 2.1, 95% CI 1.23.6) in ICSI men compared to controls were found. Furthermore, compared to men born after spontaneous conception, ICSI men were nearly three times more likely to have sperm concentrations below the WHO reference value of 15 million/ml (adjusted odds ratio (AOR) 2.7; 95% CI 1.16.7) and four times more likely to have total sperm counts below 39 million (AOR 4.3; 95% CI 1.711.3). In this small group of 54 fatherson pairs, a weak negative correlation between total sperm count in fathers and their sons was found. LIMITATIONS, REASONS FOR CAUTION The main limitation is the small study population. Also, the results of this study where ICSI was performed with ejaculated sperm and for male-factor infertility cannot be generalized to all ICSI offspring because the indications for ICSI have nowadays been extended and ICSI is also being performed with non-ejaculated sperm and reported differences may thus either decrease or increase. WIDER IMPLICATIONS OF THE FINDINGS These first results in a small group of ICSI men indicate a lower semen quantity and quality in young adults born after ICSI for male infertility in their fathers.