Independent factors associated with intracytoplasmic sperm injection outcomes in patients with complete azoospermia factor c microdeletions

Which independent factors influence ICSI outcomes in patients with complete azoospermia factor c (AZFc) microdeletions? In patients with complete AZFc microdeletions, the sperm source, male LH, the type of infertility in women, and maternal age are the independent factors associated with ICSI outcomes. AZF microdeletions are the second most prevalent factor contributing to infertility in men, with AZFc microdeletions being the most frequently affected locus, accounting for 60-70% of all cases. The primary clinical phenotypes are oligoasthenozoospermia and azoospermia in patients with complete AZFc microdeletions. These patients can achieve paternity through ICSI using either testicular (T-S) or ejaculated (E-S) spermatozoa. With aging in men with AZFc microdeletions, oligoasthenozoospermia or severe oligozoospermia may gradually progress to azoospermia. In this retrospective cohort study, the independent factors associated with the outcomes of 634 ICSI cycles in 634 couples with the transfer of 1005 embryos between February 2015 and December 2023 were evaluated. The analysis included 398 ICSI cycles in 398 couples using E-S and 236 ICSI cycles in 236 couples using T-S; all men had complete AZFc microdeletions. The inclusion criteria were as follows: (i) men had complete AZFc microdeletions and (ii) the couple underwent ICSI treatment using T-S or E-S. The exclusion criteria were as follows: (i) cycles involving frozen-thawed oocytes; (ii) cycles in which all fresh embryos were frozen and not transferred; (iii) cycles lost to follow-up; and (iv) multiple ICSI cycles, apart from the first cycle for each couple. The primary outcome was the cumulative live birth rate per ICSI cycle, whereas the secondary outcomes were the clinical pregnancy rate per ICSI cycle, fertilization rate, and the no-embryo-suitable-for-transfer cycle rate (NESTR). Moreover, the maternal and neonatal outcomes were analyzed. Continuous variables showing non-normal distributions were expressed as median and interquartile range and were analyzed using the Kruskal-Wallis test. Categorical variables were expressed as percentages and were analyzed using the χ or Fisher's exact test. Linear and logistic regression models were constructed to assess the independent factors associated with ICSI outcomes. The T-S group exhibited inferior ICSI outcomes than the E-S group, marked by significantly reduced rates of cumulative live birth, clinical pregnancy, fertilization, high-quality embryos, blasto