Menoufia Medical Journal

: 2015  |  Volume : 28  |  Issue : 2  |  Page : 471--476

Sexual and reproductive functions in men with Down's syndrome

Abdalla M Attia1, Naglaa M Ghanayem2, Heba H El Naqeeb3,  
1 Department of Dermatology, Andrology and STIs, Menoufia University, Menoufia, Egypt
2 Department of Medical Biochemistry, Faculty of Medicine, Menoufia University, Menoufia, Egypt
3 Department of Dermatology, Menoufia University , Shebin El- Kom, Egypt

Correspondence Address:
Heba H El Naqeeb
12 Amin Khyrat El Ghandour St, Mayami, Alexandria 21543


Objective The aim of this study was to evaluate sexual and reproductive functions in men with Down俟Q製 syndrome. Background Down俟Q製 syndrome is a genetic condition that occurs due to an extra copy of chromosome 21. Affected children show characteristic features and associated diseases in different body systems. All of these diseases have received much interest of researchers and can be managed. However, sexually transmitted infections (STIs), the sexual development, associated congenital anomalies of the genital organs, sexuality, and reproductive disorders of these people have not gained much attention. Patients and methods A case-control study was carried out on 21 Down俟Q製 syndrome male patients (patient group), aged 21-28 years. Another 21 healthy, age-matched volunteers were included as the control group. Full sexual history was obtained from all participants , including the age at puberty, desire of marriage and parenting children, practice of masturbation, and attraction to the other sex. Follicle-stimulating hormone, luteinizing hormone, prolactin, total testosterone, and estradiol levels were measured and the BMI was evaluated. Results Patients included in the study entered puberty and became fully sexually mature, but later than their healthy peers. More than half (57.1%) of Down俟Q製 syndrome patients were sexually active, masturbated, were attracted to the other sex, and had the desire to marry. Down俟Q製 syndrome patients showed a higher BMI. Follicle-stimulating hormone, luteinizing hormone and prolactin levels were significantly higher in Down俟Q製 syndrome patients compared with the controls. They showed a lower serum total testosterone. The serum estradiol was normal. Conclusion According to our results, some men with Down俟Q製 syndrome have normal sexual development. They can marry and father children.

How to cite this article:
Attia AM, Ghanayem NM, El Naqeeb HH. Sexual and reproductive functions in men with Down's syndrome.Menoufia Med J 2015;28:471-476

How to cite this URL:
Attia AM, Ghanayem NM, El Naqeeb HH. Sexual and reproductive functions in men with Down's syndrome. Menoufia Med J [serial online] 2015 [cited 2020 Mar 30 ];28:471-476
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Full Text


Down's syndrome is one of the most common and readily identifiable chromosomal disorders, and the most common genetic cause of intellectual disabilities among live-born infants [1] . Down's syndrome is named after John Langdon Down, the physician who first described the disease as a disorder in 1866. Although Dr Down made some important observations about the syndrome, he did not identify the cause of the disorder correctly. The genetic origin of Down's syndrome was not discovered by scientists until 1959 [2].

It is a congenital condition caused by the presence of an extra copy of genetic material on chromosome 21, either in whole, called 'trisomy 21', or in part due to unbalanced translocations or chromosomal mosaicism [3],[4].

The effects of the extra copy vary significantly among people with Down's syndrome, depending on the extent of the extra copy, the genetic background, environmental factors, and random chance. It is statistically more common with older parents [5].

Down's syndrome is associated with varying degrees of mental retardation ranging from mild to moderate, impairment of cognitive ability, delayed physical growth, and a particular set of facial characteristics in early infancy [6] . Individuals with this disease will experience varying degrees of medical and physical problems. Some people are able to lead fairly normal lives, whereas others need constant medical care [7].

The emergence of sexual behavior in individuals with Down's syndrome alarms some parents and caretakers who may rightly fear that their child's cognitive deficit makes him or her especially vulnerable to unwanted pregnancy, sexual exploitation and abuse, and to sexually transmitted disease [8] . Unfortunately, the sexual and the reproductive functions of Down's syndrome patients have not received enough attention of scientists. Very few researches in this regard exist in the literature.


The aim of this work was to study sexual and reproductive functions in adult men with Down's syndrome.

 Participants and methods

This study was carried out on 42 individuals, who were divided into two groups: group A (the patient group) included 21 Down's syndrome male patients, aged from 21 to 28 years. They were randomly selected from special schools for education and rehabilitation of children with Down's syndrome from Shebin El Kom, Menoufia Governorate, during the period from January 2012 to June 2012. Group B (the control group) included 21 completely healthy, age-matched and sex-matched individuals selected among workers and employers in the Faculty of Medicine, Menoufia University.

All participants were subjected to the following analyses: thorough history taking focusing on their age, age of the parents at the time of delivery, pubertal age, masturbation and its frequency, attraction to the other sex and the desire to marry, marital status, history of diseases, operations and drugs with exclusion of anyone having any disease, operation or drug intake that might affect the general health, sexual and/or reproductive functions in the control group only, and history of Down's syndrome in the family or relatives.

Thorough general and local examination stressing on height and weight with calculation of the BMI, secondary sex characteristics, the presence of gynecomastia, and examination of the external genitalia: penis, scrotum, testes, and cords.

Laboratory investigations

Five milliliter of venous blood was collected from all participants. These samples were placed into a plain tube, left to be clotted, and centrifuged. The serum obtained was frozen at -20°C for the estimation of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, total testosterone, and estradiol levels.

Quantitative measurement of FSH, LH, prolactin, and total testosterone was carried out using the Immulite 2000 analyzer, which is a solid-phase, two-site chemiluminescent immunometric assay. The kit used was provided by Immulite 2000 (Diagnostic Products Corporation, USA) [9],[10].

Quantitative measurements of estradiol II in the serum were performed with the electrochemiluminescence immunoassay, which was intended for use on the Roche Elecsys 1010 (Roche) immunoassay analyzer [11] .

Statistical analysis

Analyses were conducted with an IBM personal computer and statistical package SPSS (version 16; SPSS Inc., Chicago, Illinois, USA).

Student's t-test was used for continuous quantitative parametric variables and the Mann-Whitney U-test was used for nonparametric variables. Partial correlation coefficients for testing the association between variables were also applied. A P value of less than 0.05 was considered statistically significant.


Results are shown in [Table 1], [Table 2], [Table 3] and [Figure 1], [Figure 2], [Figure 3], [Figure 4].{Figure 1}{Figure 2}{Figure 3}{Figure 4}{Table 1}{Table 2}{Table 3}

[Table 1] shows that there is a significant increase in the mother's age at the time of delivery, the father's age at the time of delivery, the BMI, and the age at puberty in the patient group when compared with the control group, whereas there was no significant difference between both groups regarding age.

History taking and genital examination showed that all patients with Down's syndrome were sexually mature with normal signs of masculinization and secondary sex characteristics with normal penis and scrotum. A smaller testicular size was detected in five (23.8%) of the Down's syndrome patients. No gynecomastia was detected in any of them. Cryptorchidism was found in three (14.3%) cases: it was unilateral in one case and bilateral in two cases . Down's syndrome patients practice masturbation less commonly compared with the control group (57.1 vs. 90%). Only 57.1% of Down's syndrome patients were attracted to the other sex and had the desire to marry compared with 100% in the control group. At time of the study, only two (9.5%) individuals in the Down's syndrome group were married compared with 14 (66.7%) in the control group.

The Down's syndrome group had significantly higher FSH, LH, and prolactin levels (P < 0.05 for each), significantly lower total testosterone (P < 0.05), and no difference in the estradiol level compared with the control group [Table 3].


Down's syndrome is a relatively common chromosomal disorder. It is due to an extra copy of chromosome 21. The exact etiology of it is unknown, but it is believed to be due to advanced maternal or paternal age, virus infection, high parity, contraceptive use, smoking, alcohol, exposure to irradiation, pesticides during pregnancy, or a diet deficient in folate [1] .

Affected children show characteristic features and usually have associated diseases and congenital anomalies in different body systems. All of these anomalies and diseases are well known and can be managed. The sexual development, associated congenital anomalies of the genital organs, sexuality, reproductive disorders, and STIs of these people have not received much attention unlike the other body systems, and few researches in this regard were found [4] .

The results of the study showed that both maternal and paternal ages at the time of delivery of Down's syndrome patients were significantly higher compared with the maternal and paternal ages of the control group. These results comply with that reported by many authors in this regard, who have found that advanced maternal age, mainly, and paternal age, sometimes, at the time of pregnancy are the most important risk factors for Down's syndrome in the baby [12],[13],[14] .

Obesity has been reported to be more prevalent in Down's syndrome patients. The results of this study showed a significantly higher BMI in the Down's syndrome group compared with the control group. These results concur with that reported by Bell and Bhate [15] , Prasher [16] , Rubin et al. [17] , Rimmer and Wang [18] , Melville et al. [19] , and Moran et al. [20] . Obesity in Down's syndrome patients is considered as a health problem, as in addition to its burden on the physical health, it may adversely affect sexual maturity, sexuality, and reproductive capability [21],[22] .

The results of our study showed that there is marked and significant delay in puberty in Down's syndrome patients compared with the control group. These results agree with that reported by a few authors who studied this aspect and reported that in Down's syndrome patients, puberty occurs, but it is delayed, and these patients experience the same physical signs of sexual maturation as normal individuals [23],[24],[25] .

Delay in puberty in these boys may be due to the associated obesity and/or the hormonal imbalance [4] . None of our patients showed any anomalies in penile length, hyposadias or the testicular size. This may be due to the small number of the patients studied.

Cryptorchidism is considered to be the most common genital congenital anomaly detected in Down's syndrome patients. It is reported to occur in 5-6% of the patients [26] . In this study, we found a much higher incidence of cryptorchidism (14.3%). This may be due to the small number of patients in this study, and further studies on a large number of patients are needed.

Salemi and La Vignera [27] suggested that cryptorchidism in Down's syndrome patients may be due to failure of normal growth of the spermatic cord and/or mutation in the gene called insulin-like factor 3 and its receptor and/or fetal hormone deficiency in these patients [28],[29] .

The sexual activity of Down's syndrome men is another important issue that has been ignored by researchers. Etem and Leventhal [30] and Gerressu et al. [31] conducted studies on masturbation by Down's syndrome patients, and they found that it is less common than in their normal peers (40% vs. 75-92%), respectively.

The results showed that 57.1% of Down's syndrome patients, as reported by their parents, practice masturbation compared with 90% of the normal control. Eastgate [32] stated that masturbation by adult Down's syndrome patients may signal an emerging interest in sexuality. This study proved that this is mostly true as those who practice masturbation (57.1%) are those who are interested and attracted to the other sex, as reported by their parents, and have the desire to marry. This study found that only 9.5% of Down's syndrome patients included in this study were married compared with 66.7% of the control group.

Regarding the issue of reproductive capability, the current study found a significant difficulty in obtaining semen samples from the study patients. Hence, we considered the measurement of hormones relevant to reproduction as indicators of reproductive capability, although they are not substitutes to semen. The results showed that FSH and LH are significantly higher in the patient group. These results agree with that reported by Hasen et al. [33] , Hsiang et al. [34] , and Suzuki et al. [35] . Elevated FSH and LH are indicators of testicular failure, leading to severe hypospermatogenesis and oligospermia in a few and azoospermia in most Down's syndrome patients [36] . In contrast, statistical analysis of the results showed that the total testosterone was significantly lower in Down's syndrome patients compared with the control group. The same was reported by Hsiang et al. [34] and Suzuki et al. [35] .

In contrast, Hasen et al. [33] found that Down's syndrome patients have normal testosterone levels. Low testosterone levels in Down's syndrome patients may be due to the associated obesity, which is accompanied by increased aromatase activity, which converts testosterone to estradiol, or due to the accompanied Leyding cell dysfunction due to the excess copy of the genetic material of chromosome 21. In this study, estradiol was found to be normal in patients compared with controls. These results are in contrast to that reported by Hestnes et al. [37] .

The results of this study showed that prolactin was significantly higher in Down's syndrome patients, compared with the control group. The only similar study we found in the literature was that of Hestnes et al. [37] , who also reported an elevated prolactin level in Down's syndrome patients.

We have no explanation for the increased prolactin level in these patients, which needs further studies, but we assume that it may be due to stress, anxiety, and the emotional instability of these patients or may be drug induced as many of them receive drugs for associated health problems.

 Conclusion and recommendations

According to our results, it could be concluded that Down's syndrome patients enter full puberty and become fully sexually mature, but later than their healthy peers. Most Down's syndrome patients masturbate. They are attracted to the other sex and have the desire to marry. Although a semen analysis was not performed for the Down's syndrome group, they showed significant elevation of FSH and LH, denoting marked corruption of their spermatogenesis. Further studies are highly essential to investigate the different sexual and reproductive issues of these patients. These studies must include a large number of patients presenting different age groups, starting from infancy and childhood to adolescence, adulthood, and advanced age.


The authors are indebted to all members who helped them complete this study.

Conflicts of interest

There are no conflicts of interest.


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