Context: Although studies to determinate and relate the prolactin and TSH serum levels with the female infertility. In men infertility those doesn’t exist.
Objective: To relate the prolactin and TSH serum levels in male patients who have a semen analysis, a complete record and are attended at the infertility clinic.
Materials and methods: An ambispective study, with a total of 85 male patients of infertility couples who attended the infertility clinic and had a semen analysis and a complete endocrinological profile were included to the statistical analysis comparing the results.
Results: A total 85 patients met the inclusion criteria: 8 of 85 patients with TSH: 2.5-3.9mU/mL, 6 patients TSH: >4mU/mL, 2 had TSH: <0.5mU/mL and 69 had TSH: 0.5-2.5. Patients in the prolactin group 8 of 85 had prolactin>20ng/dL and 77 had prolactin levels<20ng/dL. In the group of TSH 2.5- 3.9mU/mL the teratozoospermia were found to be higher than the group TSH: 0.5/2.5mU/mL (6% vs 37% respectively), although without statistical significance, in the group TSH>4mU/mL the teratozoospermia were higher (50%, p=0.006). In the group of prolactin>20ng/ dL teratozoospermia and asthenozoospermia were higher than the prolactin<20ng/dL without statistical significance (p=0.113 and p=0.353 respectively)
Conclusion: The TSH levels above 4 mU/mL are related to abnormalities in the sperm morphology. Prolactin levels greater than 20ng/dL does not show an association with alterations in sperm parameters.
There are few studies in men to determine the role of thyroid hormones and prolactin in male infertility. Among the studies conducted, Corrales et al. (1990) analyzed semen samples in patients with hypothyroidism and found that it adversely affected sperm quality by compromising ejaculate volume and sperm motility . Krassas et al. (2008) conducted another study in men with hypothyroidism and found alterations in morphology and decreased motility . On the other side, Clyde et al. (1976) studied infertile patients with hypertiroidism, reporting oligospermia and decreased motility, which were corrected after the patients received treatment . Hyperprolactinemia is related to infertility, sexual impotence and decreased reproductive potential . Segal et al. (1976) found in patients with infertility and severe sperm alterations prolactin levels significantly higher (25ng / dL) compared with the group of patients without infertility (16ng / dL). In this study, treatment with bromocriptine corrected the sperm count to normal values . The concentration of prolactin in the seminal plasma is two to three times higher than the serum concentration. Segal et al, studied patients with male infertility with sperm abnormalities due to oligo/azoospermia and asthenozoospermia, reporting excessively high levels of serum and seminal prolactin . The aim of this study is to investigate the relationship of serum TSH and prolactin levels with sperm parameters in male patients of couples who come for infertility.
An ambispective, observational and comparative study carried out in the University Center of Reproductive Medicine of the University Hospital of the Autonomous University of Nuevo Leon.
The study was conducted from October to December 2018 according to the sample size calculation with an expected proportion of 10% in a finite population of 830 subjects with 95% confidence and an accuracy of 5%. All patients who attended the consultation due to infertility for the first time were included. A blood sample was taken to assess TSH and serum prolactin, analyzed with MINI VIDAS® Compact multiparametric immunoanalyzer machine. The sample was obtained according to the techniques recommended in the 2010 WHO manual for the study of spermogram, quantifying the volume of the ejaculate, sperm count per milliliter, progressive motility and strict Kruger morphology
Statistical analysis was carried out using the SPSS® version 25 program. In the descriptive analysis of the discrete variables the median was used, and in the continuous the mean. The qualitative demographic variables were analyzed with contingency tables using Chi square and Fisher’s exact test; the quantitative ones comparing means with Student’s T and Mann Whitney. The confidence interval was 95%. P value <0.05 to statistical significance.
We analyzed 85 patients of 37 ± 6 years of whom 49% of the cases were found with some altered sperm parameter (Table 1). From serum TSH values, we found TSH 2.5 presenting sperm alterations in 57%, 7% were located with TSH greater than 4 mU / mL, in this group the number of altered spermograms was increased to 66% (Table 2). The serum prolactin values were altered in 9% of which 75% of these presented sperm alterations compared to 46% of the cases with prolactin values below 20ng / dL (Table 3).
The prevalence of hyperthyroidism in our study was 2%, and the cases of hypothyroidism was 7% similar to that found by Lotti et al of 2% and 7.4% respectively (2016) , however in in our study, we took lower TSH reference values, because these have been shown to have a deleterious effect on fertility in female patients . Regarding hyperprolactinemia, we found it was 9.4%, which coincides with reported by Hasan et al . In the analysis of patients with sperm abnormalities, there were no cases with alterations in the TSH group < 0.5 mU / mL different from previous reports , but this has been related to the low number of our case series. In the group with the ideal TSH parameter, the prevalence of sperm alterations was 49%, considering all the cases with at least one parameter below that published by the WHO, which represents a much higher estimate of 20 to 30 % as an isolated factor of infertility. When the TSH concentration rose above 2.5, alterations in morphology increased considerably, and when it increased > 4 mU / mL, both morphology and motility were altered in more than 50% of cases, with statistical significance for morphology (p=0.006). The prevalence of sperm alterations that we find in patients with prolactin levels < 20 ng/ dL is similar to that found in patients with ideal TSH values of this study, also much higher than that reported by the WHO. When patients presented with hyperprolactinemia, the prevalence increased up to 75% in general, predominating alterations in morphology, motility and azoospermia, no statistical significance. We consider that this disparity was presented because the population group studied is one that already have a condition associated with infertility and come to our office, however, it was evident that as the TSH and prolactin values increase, this prevalence is still very much higher. We estimate that a mechanism of hypogonadotropic hypogonadism is associated that we could not determine due to not having studied these variables. As a strength of our study, we did not find another publication of sperm analysis with such low TSH parameters included. The main weakness with which we found was the limitation in casuistry. Another limitation is the failure to investigate the endocrinological and histopathological consequences associated with hypothyroidism and hyperprolactinemia.
The TSH levels above 4 mU/mL are related to abnormalities in the morphology. The prolactin levels greater than 20ng/dL does not show statistical significance.
The authors thank Dr. Luis Rodrigo Sanchez Gonzalez for writing assistance.
1.Corrales Hernández JJ, García Miralles JM, Diez García LC. Primary hypothyroidism and human spermatogenesis. Arch Androl. (1990), 25: 21-27.
2. Krassas GE, Papadopoulou F, Tziomalos K, Zeginiadou T, Pontikides N. Hypothyroidism has an adverse effect on human spermatogenesis: a prospective, controlled study. Thyroid. (2008), 18(12): 1255-1259.
3. Clyde HR, Walsh PC, English RW. Elevated plasma testosterone and gonadotropin levels in infertile males with hyperthyroidism. Fertil Steril. (1976), 27(6): 662-666.
4. Bouilly J, Sonigo C, Auffret J, Gibori G, Binart N. Prolactin signaling mechanisms in ovary. Mol Cell Endocrinol. (2012), 356(1-2): 80- 87.
5. Segal S, Polishuk WZ, Ben-David M. Hyperprolactinemic Male Infertility. Fertility and Sterility. (1976), 27(12): 1425-1427.
6. Segal S, Ron M, Laufer N, Ben-David M. Prolactin in Seminal Plasma of Infertile Men. Arch Andrology. (1978), 1(1): 49-52.
7. Lotti F, Maseroli E, Fralassi N, Degl’Innocenti S, Boni L, et al. Is thyroid hormones evaluation of clinical value in the work-up of males of infertile couples? Hum Reprod. (2016),31(3): 518-529.
8. Roberto N. Thyroid and Assisted Reproduction Technologies: A Brief Clinical Update with Recommendations for Practice. Endocr Metab Immune Disord Drug Targets. (2018); 18(3): 194-200.
9. Hasan R, Weerasooriya T, Illeperuma I, Weerasinghe WS, Withana AK. Prolactin and male infertility. Sri Lanka Medical Association, 126th Anniversary Scientific Medical Congress. 2013; 58 Supplement 1:59. Colombo. Water’s Edge: Battaramulla, 2013.