To determine the frequencies and the characteristics of Y chromosome microdeletion in infertile men from northeastern China to perform appropriate therapeutic choices.

The study included 1738 infertile men. Sperm concentration was measured according to standard methods and karyotype analysis was performed on peripheral blood lymphocytes with standard G-banding. Multiplex polymerase chain reaction amplification using 9 specific sequence-tagged sites were selected to detect Y chromosome microdeletions.

The data showed that the frequency of Y chromosome microdeletion was 8.57%. The most common microdeletion, among the azoospermia factor (AZF) regions, was detected in the AZFc region, followed by AZFb+c, AZFb, AZFa+b+c, AZFa, and AZFa+c. One-hundred seven patients with Y chromosome microdeletion developed azoospermia, 39 developed severe oligozoospermia (sperm concentration ≤5 × 10⁶/mL), and 3 developed moderate oligozoospermia (sperm concentration >5 × 10⁶/mL and ≤10 × 10⁶/mL). Karyotype analysis was available for 130 patients with Y chromosome microdeletion and abnormal karyotypes were found in 19 patients (14.6%). The most frequent abnormal karyotype was 46,X,Yqh-(n = 7).

In northeastern China, Y chromosome microdeletion diagnosis should be performed before the use of intracytoplasmic sperm injection in infertile men with sperm count ≤10 × 10⁶/mL, especially in men with azoospermia.