Peter N Schlegel   Professor of Urology

  • +1 212 746 5491

Male infertility, hormonal action in men


Our research projects involve both clinical and laboratory research on prostate cancer, male infertility and male reproductive physiology.

Genetic abnormalities of infertile men. eMen with the most severe abnormalities in sperm production, and hence the most severe male factor infertility problems commonly have a genetic abnormality as the cause of infertility.  However, beyond  karyotypic abnormalities and micro deletions of the Y chromosome, relatively few of these causes of infertility can be directly identified.  Based on the large volume of patients treated by Dr. Schlegel and long-standing, IRB-approved processes to examine and store DNA samples from these patients, we have an unequalled opportunity to identify genetic factors involved with male infertility.  Such identification is necessary for future treatment of many of these patients.


We have been able to effectively correlate the phenotype of these patients based on the heterogeneous function of the testis with correlation to genetic testing to provide effective characterization of the clinical relevance of genetic abnormalities as well.  For example, our center has been the primary site for identification of the prognostic value of Y chromosome microdeletions, AZFa, AZFb, and AZFc.   Our laboratory is interested in the evaluation of infertile men for these genetic abnormalities as well as defining what genetic problems actually cause the infertile state.  We hope to further use this genetic information with stem cell technologies to generate further treatment options for men who cannot currently be treated for male infertility.  Some of this work continues with collaborative efforts within the Center for Reproductive Genomics at Cornell's Veterinary School in Ithaca, NY.

Hormonal abnormalities in male infertility. Men with the most severe defects in sperm production will commonly have hormonal abnormalities such as increased conversion of testosterone to estrogen (increased aromatase activity.)  Our translational research continues to examine the basis for these genetic abnormalities as well as to provide novel approaches for treatment of men with such hormonal abnormalities.

Prostate Cancer  We have previously performed some of the critical studies to identify the neuroanatomy of the pelvis that provides the basis for current surgical treatment of prostate cancer including robotic assisted laparoscopic prostatectomy.  We have also been principal investigators in development of the novel hormonal agent, histrelin acetate implants, (both US and international studies) that is now an FDA-approved drug for treatment of prostate cancer (Vantas).

Clinical studies in male infertility. We have extensive experience with sperm extraction in association with assisted reproductive techniques. This includes treatment of men with obstructive azoospermia as well as men with testicular failure, where inadequate numbers of sperm are produced to be found in the ejaculate, but a few rare sperm can be extracted directly from testicular tissue.


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Funding awarded

  • On-Demand Pharmacological Contraception by Blocking ADCY 10  awarded by National Institute of Child Health & Human Development Co-Investigator 2019 - 2022
  • Genetics of Male Infertility: A Marker of Overall Health- Project 1  awarded by National Institute of Child Health & Human Development Principal Investigator Subaward 2019 - 2024



full name

  • Peter N Schlegel

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