Past Issue

Volume 11, Number 2, Jul-Sep 2017, Pages: 117-122

Sperm Retrieval in Patients with Klinefelter Syndrome: A Skewed Regression Model Analysis

Mohammad Chehrazi, Ph.D, 1, 2, Abbas Rahimiforoushani, Ph.D, 2, *, Marjan Sabbaghian, Ph.D, 3, *, Keramat Nourijelyani, Ph.D, 2, Mohammad Ali Sadighi Gilani, M.D, 3, 4, Mostafa Hoseini, Ph.D, 2, Samira Vesali, M.Sc, 1, Mehdi Yaseri, Ph.D, 2, Ahad Alizadeh, M.Sc, 1, Kazem Mohammad, Ph.D, 2, Reza Omani Samani, M.D, 1,
Department of Epidemiology and Reproductive Health, Reproductive Epidemiology Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
Department of Urology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
Student Research Committee, Mazandaran University of Medical Science, Sari, Iran
*Corresponding Addresses: P.O.Box: 14155-6446 Department of Epidemiology and Biostatistics School of Public Health Tehran University of Medical Sciences Tehran Iran P.O.Box: 16635-148 Department of Andrology Reproductive Biomedicine Research Center Royan Institute for Reproductive Biomedicine ACECR Tehran Iran Emails:,marjan.sabbaghian@gmail.comRoyan Institute



The most common chromosomal abnormality due to non-obstructive azoospermia (NOA) is Klinefelter syndrome (KS) which occurs in 1-1.72 out of 500-1000 male infants. The probability of retrieving sperm as the outcome could be asymmetrically different between patients with and without KS, therefore logistic regression analysis is not a well-qualified test for this type of data. This study has been designed to evaluate skewed regression model analysis for data collected from microsurgical testicular sperm extraction (micro-TESE) among azoospermic patients with and without non-mosaic KS syndrome.

Materials and Methods

This cohort study compared the micro-TESE outcome between 134 men with classic KS and 537 men with NOA and normal karyotype who were referred to Royan Institute between 2009 and 2011. In addition to our main outcome, which was sperm retrieval, we also used logistic and skewed regression analyses to compare the following demographic and hormonal factors: age, level of follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone between the two groups.


A comparison of the micro-TESE between the KS and control groups showed a success rate of 28.4% (38/134) for the KS group and 22.2% (119/537) for the control group. In the KS group, a significantly difference (P<0.001) existed between testosterone levels for the successful sperm retrieval group (3.4 ± 0.48 mg/mL) compared to the unsuccessful sperm retrieval group (2.33 ± 0.23 mg/mL). The index for quasi Akaike information criterion (QAIC) had a goodness of fit of 74 for the skewed model which was lower than logistic regression (QAIC=85).


According to the results, skewed regression is more efficient in estimating sperm retrieval success when the data from patients with KS are analyzed. This finding should be investigated by conducting additional studies with different data structures.