We review the literature on reproductive system in male patients with trisomy 21/Down syndrome (DS), and reports on fertile patients. The DS men phenotype includes genitourinary abnormalities, hypogonadism, decreased libido, and erectile dysfunction. Semen analysis commonly reveals azoospermia and oligozoospermia. Spontaneous conceptions in female partners of four men with DS have been reported in the literature, as well as healthy life birth after in vitro fertilization (IVF). Because of possible fertility in DS patients, it is essential to inform them and their caregivers about reproduction and contraception issues. Since increased risk of aneuploidy, prenatal genetic screening is highly recommended.

Keywords: human reproduction, chromosomal abnormalities, trisomy 21, azoospermia, spermatogenesis, Down syndrome, reproductive system, infertility