ABSTRACT
<p><b>AIM</b>To describe the reproductive outcome following intracytoplasmic sperm injection (ICSI) for male factor infertility associated with Crohn's disease and 6-mercaptopurine (6-MP) chemotherapy.</p><p><b>METHODS</b>The male partner of a couple suffered from severe Crohn's disease and received a 3-month course of 6-MP for this condition. Two spontaneous conceptions were established before 6-MP, although post-chemotherapy semen analysis found the sperm concentration to be 8,000/mL. In vitro fertilization (IVF) with ICSI and embryo transfer was performed.</p><p><b>RESULTS</b>The woman underwent an uncomplicated controlled ovarian hyperstimulation sequence using a combined rec-FSH+hMG protocol, following late luteal phase pituitary downregulation. This culminated in the retrieval of 18 oocytes, 11 of which were fertilized with ICSI. She later delivered a normal male infant without urogenital anomaly. Four nontransferred blastocysts were cryopreserved.</p><p><b>CONCLUSION</b>This report describes the first successful birth after ICSI for severe oligozoospermia associated with Crohn's disease and 6-MP therapy. We outline salient features of Crohn's disease, 6-MP pharmacology, and their relevance to human fertility.</p>