Associations Between Reproductive Disorders and Specific Physical, Mental, Personality, and Social Characteristics: A Narrative Review

ABSTRACT

Background and Aims

The present review aims to ascertain whether reproductive disorders are associated with specific physical, mental, personality, and social traits. This information may be used to support or reject the hypothesis on the origin of infecundity, which proposes that women/men with preferred characteristics, including high resource holding potential, genetic quality, and/or reproductive potential have advantage over women/men displaying less preferred traits in selecting partners with preferred traits.

Methods

A literature search of the reported associations of endometriosis, polycystic ovary syndrome, diminished ovarian reserve in women < 35 years, and low semen quality with specific physical, mental, personality, and social characteristics was carried out using the PubMed database.

Results

Endometriosis is associated with lower body mass index and waist‐to‐hip ratio, greater breast‐to‐underbreast ratio, severe teenage acne, red hair, fair skin, nevi and freckles, light eyes, and high sensitivity to sun exposure. Polycystic ovary syndrome is linked to central adiposity, waist‐to‐hip ratio > 0.80, acne vulgaris, acanthosis nigricans, and hirsutism in both obese and lean women, and lower cognitive performance on memory, executive function, attention, information processing speed, and visuospatial skills. Diminished ovarian reserve in women < 35 years is associated with shorter cycle length and menstrual bleeding length, either shorter or longer than 4–6 days. Sperm quality is negatively correlated with body mass index, waist circumference, weight gain since age 17 years, extraversion, and psychoticism, but positively correlated with general intelligence. The four reproductive disorders analyzed are significantly associated with high levels of anxiety, stress, and/or depression, as well as economic burden (endometriosis) or lower socioeconomic status (polycystic ovary syndrome, diminished ovarian reserve, and low semen quality).

Conclusion

This study discloses specific physical, mental, personality, and social traits associated with four reproductive disorders. More efforts are warranted to evaluate traits associated with reproductive disorders using a multiethnic and multicultural viewpoint.

1. Introduction

A previous cross‐sectional study [1] showed that couples consisting of women with a relative low ovarian reserve and men suffering from any combination of oligo‐, astheno‐, and teratozoospermia are overrepresented in couples seeking assisted reproductive technology (ART) treatment for the first time after experiencing > 2 years of infertility. These data enabled us to generate a hypothesis on the origin of couples' infecundity. This hypothesis suggests that a process of sexual selection for physical, mental, personality, and/or social traits determines the particular mate choice decision a person makes. In short, this hypothesis is grounded on the premise that each person has his/her own mate preferences based on anthropometric and morphological traits, as well as on social, educational, behavioral, and/or personality characteristics that provide cues of resource holding potential, genetic quality, and/or reproductive potential [2, 3, 4, 5]. Therefore, mate choice decisions are usually made in a non‐random way. Specifically, individuals most often select mates based on phenotypic similarity to themselves [5, 6, 7]. This type of mating is called positive assortative mating [8].

Literature shows that women and men do not have the same mate preferences. Actually, a cross‐cultural study including a 45‐country sample of 14,399 participants shows that men, more than women, prefer attractive, young mates; and women, more than men, prefer older mates with financial prospects. Nonetheless, sex differences in age preferences tend to fade as gender equality increases [9]. Remarkably, final mate choice decisions are not always based on mate preferences. According to our hypothesis, sexual selection acts shaping mate choice preferences, in such a way that women/men displaying preferred physical, mental, personality, and/or social traits would have an advantage over women/men displaying less preferred characteristics in selecting partners exhibiting preferred traits. Consequently, women/men exhibiting less preferred traits would have to settle for choosing partners similar to themselves [10]. In other words, women/men with less preferred traits would have fewer mating options compared with women/men with preferred characteristics. Thus, these women/men would be less demanding regarding less preferred traits of prospective mates [11]. The resulting couples would have lower probabilities of achieving a spontaneous pregnancy and live birth, and may eventually seek infertility treatment. As expected, literature shows significant correlations between the members of infertile couples seeking ART treatment for a range of physical, social, and behavioral traits, as well as for a range of lipids and some other metabolic measures [3]. In addition, reproductive disorders are not only genetically and clinically linked with other diseases in single meta‐diseases, but may also be associated with specific physical and cognitive traits [12]. For instance, premature ovarian failure is associated with psychosexual dysfunction, mood disorders, and dementia; endometriosis is related with severe teenage acne and high sensitivity to sun exposure; and sperm concentration, count, and motility are positively correlated with general intelligence [12].

Our hypothesis on the origin of couples' infecundity opens a new line of research that needs to be explored. As mentioned above, our hypothesis predicts that, once a mate choice decision has been made, couples displaying less preferred traits would be overrepresented in the subpopulation of couples seeking infertility treatment. In order to find evidence supporting or refuting the hypothesis on the origin of couples' infecundity, the present study aims to perform a literature search of the reported associations between reproductive disorders and specific physical, mental, personality, and social characteristics. Because literature on this topic is still beginning to emerge and there are not yet enough data to conduct a systematic review, a narrative review format has been used.

2. Methods

A search of the available literature indexed in PubMed database on publications from inception up to November 2025 was performed. The literature search was focused on English‐language scientific publications. No sample size thresholds were used as inclusion/exclusion criteria. Studies were identified using a combination of the following search terms: “endometriosis”, “polycystic ovary syndrome”, “ovarian reserve”, “idiopathic or unexplained or unknown female infertility”, “semen quality”, “oligozoospermia”, “asthenozoospermia”, “teratozoospermia”, “social relationships”, “socioeconomic status”, and “physical or phenotypic or anthropometric or morphological or psychological or psychiatric or cognitive ability or intelligence or personality traits”. In addition, a manual search to explore the references cited in the primary articles was carried out. Studies that did not adhere to these selection criteria were excluded. Notably, the concept “socioeconomic status” includes a combination of economic (income, education, occupation) and sociological (social status and class) factors in relation to others [13]. Thus, the literature search was focused only on the term “socioeconomic status”. In addition, for the sake of simplicity, the terms “infertility” and “infecundity” were used indistinctly, despite these words designating different concepts. In particular, “infertility” is defined as “a disease characterized by the failure to establish a clinical pregnancy after 12 months of regular, unprotected sexual intercourse or due to an impairment of a person's capacity to reproduce either as an individual or with his/her partner” [14]. In contrast, “infecundity” is “the biological inability of a man, a woman or a couple to produce a live birth” (https://www.ined.fr/en/glossary/infecundity/). Nevertheless, it is important to emphasize that the final reproductive goal of a couple is to have a live birth (i.e., to be fecund), not to have a clinical pregnancy (i.e., to be fertile). A total of 515 original publications and literature reviews were identified using the search strategy. After assessment of the titles, abstracts, and text by the three coauthors, a total of 46 publications were finally selected for inclusion in the study. These publications are shown in Tables 1, 2, 3, 4. It should be highlighted that human physical and behavioral phenotypes, as well as mate choice preferences, may vary considerably among ethnic populations and cultures. Therefore, special attention was paid to including in the footnotes of Tables 1, 2, 3, 4 all the information provided by the original studies on the specific populations analyzed (e.g., age, ethnicity, and other key demographic variables), as well as on the geographic origin of the studies. It is important to emphasize the correlational nature of the associations reported in the present study. In no way, the data shown in the study can be used to make causal inferences between physical, mental, personality and social traits, and reproductive disorders.

Table 1.

Physical, mental, and social traits associated with endometriosis.

Traits		Reference
Anthropometric	Although some studies do not observe significant differences, most studies report lower BMI, low amounts of adipose tissue, and a preponderance of peripheral adipose tissue distributed below the waist, small waist circumference, low WHR, and greater breast‐to‐underbreast ratio	For review, see Hong and Yi [15]; for systematic review, see Backonja et al. [16]
Morphological	Severe teenage acne, red hair, fair skin, nevi and freckles, light eyes, and high sensitivity to sun exposure	For reviews, see Tarín et al. [12]; Viganò et al. [17]
	Having green eyes increases by ≈ fourfolds the risk for ureteral nodule. This risk may even be increased up to more than fivefolds by having both green eyes and blonde/light brown hair	Salmeri et al. [18]a
Psychological and psychiatric	Tendency to suffer from general distress (depression, anxiety, and stress), affective, panic‐agoraphobic, and substance use psychiatric disorders, body image disturbance, eating disorders, and poor quality of life, especially in women with pelvic pain	Barberis et al. [19]b; for reviews, see Carbone et al. [20] and Dipankar et al. [21]; for systematic reviews, see Szypłowska et al. [22], Rempert et al. [23], and Zippl et al. [24]; for systematic review of systematic reviews, see Maulenkul et al. [25])
Social relationships	After the onset of chronic pelvic pain, women experience progressive social isolation, including avoidance of partner intimacy, isolation from family and friends. Women with profound chronic pelvic pain (especially dyspareunia) exhibit a greater perceived negative effect on intimate relationships, leading to poor psychological health	For review, see Chandel et al. [26]
Socioeconomic status	Economic burden because of a loss of productivity at work and higher utilization of primary and secondary health resources, even 10 years before being diagnosed	Røssell et al. [27]c; Mishra et al. [28]d; Rasp et al. [29]e; Melgaard et al. [30]f; for review, see Della Corte et al. [31]

Abbreviations: BMI, body mass index; WHR, waist‐to‐hip ratio.

^a 575 endometriotic women, aged 18–45 years, of Italian origin and ancestry.

^b 364 endometriotic women, aged 18–58 years, of Italian nationality, and who identified themselves as Caucasian.

^c Data from two Danish sources: (a) 2,650,554 women, aged 18–65 years, living in Denmark, of which 42,741 (1.6%) had been diagnosed with endometriosis; (b) 6676 women that responded a questionnaire, of which 267 (4.0%) reported to have endometriosis.

^d 1909 and 1502 endometriotic women, aged 43–48 years and 26–32 years, respectively, and 7636 and 6008 aged‐matched control women, respectively, without endometriosis. Online or postal questionnaires information was collected from the Australian Longitudinal Study on Women's Health (ALSWH).

^e 2680 women, aged < 25 years, with a surgical diagnosis of endometriosis and 5338 aged‐matched control women of the same age and municipality who were alive and had no surgical diagnosis of endometriosis. Endometriotic women were identified using the Finnish Hospital Discharge Register (FHDR). Data of control women were retrieved from the Finnish Population Information System.

^f 21,616 endometriotic women, aged 15–55 years (mean age [standard deviation]: 34.6 (8.9)), who had a first‐time hospital‐based diagnosis of endometriosis at some point during the study period (2000–2017), and 108,080 aged‐matched controls that lived in Denmark for at least 10 consecutive years.

Table 2.

Physical, mental, and social traits associated with PCOS.

Traits		Reference
Anthropometric	Central adiposity and WHR > 0.80 (77.2% vs. 63.3%) in both obese and lean women, respectively	For systematic review and meta‐analysis, see Parsaei et al. [32]; Makhija et al. [33]a
Morphological	Acne vulgaris (90.9% vs. 56.7%), acanthosis nigricans (28.8% vs. 3.3%), and hirsutism (90.9% vs. 66.7%) in both obese and lean women, respectively	Makhija et al. [33]a
Psychological and psychiatric	Lower cognitive performance on memory, executive function, attention, information processing speed, and visuospatial skills	For review, see Naz et al. [34]
	High prevalence of anxiety and depression of different severity, although mild symptoms are more common. Obese women exhibit increased odds of depressive symptoms compared with controls	For systematic review and meta‐analysis, see Wang et al. [35]
	Increased risks of eating disorders, psychosexual dysfunction, and decreased quality of life	For systematic review, see Alur‐Gupta et al. [36]
	Psychosexual dysfunction is affected across multiple subdomains, including arousal, lubrication, orgasm, and pain, as well as total sexual function and sexual satisfaction. Excess body hair has a negative effect on sexuality, sexual attractiveness, and sexual satisfaction	For systematic review and meta‐analysis, see Pastoor et al. [37]
	Less body appreciation, including body acceptance, body respect and care, and resistance to media‐promoted appearance ideals	Jannink et al. [38]b
Social relationships	High levels of social anxiety and avoidance, mainly those PCOS women suffering from oligomenorrhea‐hirsutism and overweight‐obesity	Açmaz et al. [39]c
Socioeconomic status	Increased risk of PCOS in women with low socioeconomic status	Rubin et al. [40]d

Abbreviations: PCOS, polycystic ovarian syndrome; WHR, waist‐to‐hip ratio.

^a 66 obese and 30 lean PCOS women, aged 15–45 years, recruited by the Jawaharlal Nehru Medical College's Acharya Vinoba Bhave Rural Hospital in Sawangi (Meghe), Wardha, India.

^b 492 PCOS women (mean age: 30.8 years; range: 20.0–42.0 years) and 511 non‐PCOS women with other infertility diagnoses (mean age: 33.4 years; range: 21.0–43.0 years). Women provided self‐reported data through a web‐based questionnaire, invited by two Dutch patient organizations and by 28 Dutch fertility clinics through posters and leaflets.

^c 86 PCOS patients (mean age: 24.3–26.1 years) from the Kayseri Education and Research Hospital of Medicine, Turkey, and 47 control healthy volunteer participants in reproductive age (mean age: 27.8 years).

^d 14,705 PCOS women, aged 25–60 years (median age: 33 years), and 41,584 age‐matched controls from the Danish National Patient Register.

Table 3.

Physical, mental, and social traits associated with DOR in women < 35 years.

Traits		Reference
Anthropometric	No significant relationship between fluctuating asymmetry and serum AMH levels	Żelaźniewicz et al. [41]a
	A menstrual cycle length of < 25 days is associated with a lower number of growing follicles and MII oocytes retrieved after controlled ovarian stimulation in oocyte donor cycles compared with cycle lengths of 27–29 days. Furthermore, menstrual bleeding length shorter or longer than 4–6 days is associated with a lower number of MII oocytes retrieved	Vassena et al. [42]b
	Menstrual cycle length is significantly shorter in women with occult POI displaying AMH ≤ 1.1 ng/mL versus women with AMH > 1.1 ng/mL	Guzel et al. [43]c
Psychological and psychiatric	Self‐reported psychological stress is negatively associated with AFC and serum AMH levels. These associations are primarily found among women < 35 years compared with women ≥ 35 years	Mínguez‐Alarcón et al. [44]d
Socioeconomic status	Compared with women with a middle and high socioeconomic status, women with a low socioeconomic status display significantly lower serum AMH and AFC levels	Surekha et al. [45]e; Barut et al. [46]f
	There is a consistent association between socioeconomic adversity and earlier age at menopause (a proxy measure of ovarian reserve)	For review, see Richardson et al. [47]
	There is a weak, positive association between age at natural menopause and educational level (considered one of the best socioeconomic indicators)	For review, see Canavez et al. [48]

Abbreviations: AFC, antral follicle count; AMH, anti‐Müllerian hormone; BMI, body mass index; DOR, diminished ovarian reserve; MII, metaphase II; POI, primary ovarian insufficiency.

^a 53 healthy, non‐pregnant, naturally cycling women from an urban population, aged 20–28 years, mostly students at the University of Wrocław, Poland.

^b 1953 oocyte donors, aged 18–35 years, of Caucasian phenotype from Barcelona, Spain, that underwent 2015 donation cycles and 3427 embryo transfer cycles.

^c 963 students, aged < 30 years, from the main campus of Istanbul Aydin University, Turkey.

^d 520 women to ascertain AFC values and 185 women to evaluate serum AMH levels, aged 18–45 years, seeking infertility treatment at the Massachusetts General Hospital Fertility Center, Boston, USA.

^e 160 married healthy women with normal menstrual cycles (25–35 days), aged 20–35 years, who attended the Gynecology department of a tertiary care teaching hospital, Rajahmundry, Andhra Pradesh, India.

^f 101 married women, aged 20–35 years, who presented to the Department of Obstetrics and Gynecology, HRS IVF Center, Ankara, Turkey, and had regular, menstrual cycles of 21–45 days, no evidence of endocrine disorders, a BMI ranging from 18–28 kg/m², not on hormone therapy for previous 3 months, and no history of ovarian surgery.

Table 4.

Physical, mental, personality, and social traits associated with low semen quality.

Traits		Reference
Anthropometric	Non‐significant relationship between three phenotypic traits (length of the second to the fourth finger, fluctuating asymmetry, and facial attractiveness) and sperm concentration, count, and motility	For a comprehensive review and meta‐analysis, see Jeffery et al. [49]
	BMI, waist circumference, and weight gain since age 17 years are positively associated with poorer semen volume, sperm concentration, and sperm total count	Joseph et al. [50]a
Psychological, psychiatric, and personality	Sperm concentration, count, and motility show a modest but significant positive correlation with general intelligence	Arden et al. [51]b
	Extraversion, anxiety, and psychoticism are negatively associated with sperm count, morphology, motility, and vitality	Conrad et al. [52]c
	Increased levels of both state and trait anxiety are associated with lower semen volume, sperm concentration and count, reduced sperm motility, and increased sperm DNA fragmentation	Vellani et al. [53]d
	Men's self‐reported psychological stress is associated with lower mean levels of total sperm count, normal morphology count, and the number of cells with high DNA damage	Reddy et al. [54]e
Socioeconomic status	Use of non‐private insurance is associated with higher odds of abnormal concentration, motility, morphology, and total motile sperm count. In contrast, higher neighborhood median income is associated with lower odds of abnormal sperm concentration and total motile sperm count	Hudnall et al. [55]f
	Low socioeconomic status is negatively associated with sperm concentration, total sperm count, total motile sperm count, and percentage of total and progressive sperm motility	Horns et al. [56]g; Gago et al. [57]h; Badreddine et al. [58]i
	Men's self‐reported lower annual incomes and education levels are associated with dysregulation in sperm DNA methylation patterns	Stalker et al. [59]j

Abbreviations: BMI, body mass index; IVF, in vitro fertilization.

^a 659 men, aged ≥ 21 years, participating in a semen testing substudy of the Pregnancy Online Study (PRESTO), a cohort study of pregnancy planners from the United States and Canada.

^b 425 US Vietnam‐era Army veterans, aged 31–44 years.

^c 84 men, aged 23–45 years, attending an infertility service in Bonn, Germany.

^d 30 first‐attempt IVF men, aged 29–49 years, of the Centre for Reproductive Medicine and Biology, European Hospital, Rome, and 29 men, aged 31–48 years, participants in “Health Care Day” at the same center.

^e 718 male partners, aged 18–55 years, of couples seeking infertility treatment at the Massachusetts General Hospital.

^f 2750 white non‐Hispanic, black non‐Hispanic, Hispanic, and Asian men, who underwent semen analysis for fertility evaluation at an integrated academic health care system, Chicago, Illinois, USA.

^g 13,873 men (median age: 31 years, interquartile range: 27–35 years), who underwent semen analysis for fertility evaluation at the University of Utah Health and Intermountain Healthcare.

^h 8446 men (median age: 35 years, interquartile range: 32–40 years), who underwent semen analysis for fertility evaluation across a tertiary USA healthcare system.

ⁱ 11,134 men (median age: 35 years, interquartile range: 32–40 years), who used mail‐in fertility testing services provided by GiveLegacy, a company based in Boston, USA, that provides fertility testing services by mail.

^j 1471 male partners, aged ≥ 18 years, of couples planning infertility treatment at four US reproductive endocrinology and infertility centers. These men participated in a multicenter randomized folic acid and zinc supplementation clinical trial.

3. Physical, Mental, Personality, and Social Traits Associated With Reproductive Disorders

3.1. Endometriosis

Table 1 shows physical, mental, and social traits associated with endometriosis. These women exhibit several anthropometric traits suggesting they may have high reproductive potential [60]. Specifically, lower body mass index (BMI) and waist‐to‐hip ratio (WHR), and greater breast‐to‐underbreast ratio (for review, see Hong and Yi [15]; for systematic review, see Backonja et al. [16]). Endometriosis is also associated with particular morphological traits such as severe teenage acne, red hair, fair skin, nevi and freckles, light eyes, and high sensitivity to sun exposure (for reviews, see [12, 17]). Interestingly, several pigmentation phenotypes, defined by combining eye and hair color, are associated with distinct prevalence of endometriosis localizations. For instance, compared with other endometriosis localizations, having green eyes and blonde/light brown hair is associated with a risk more than fivefold for ureteral nodule, a specific location of deep infiltrating endometriosis, even after adjusting for anthropometric confounders [18]. Furthermore, in the psychological and psychiatric sphere, endometriotic women tend to suffer from general distress (depression, anxiety, and stress), affective, panic‐agoraphobic, and substance use psychiatric disorders, body image disturbance, eating disorders, and poor quality of life, especially in women with pelvic pain [19] (for reviews, see Carbone et al. [20] and Dipankar et al. [21]; for systematic reviews, see Szypłowska et al. [22], Rempert et al. [23], and Zippl et al. [24]; for systematic review of systematic reviews, see Maulenkul et al. [25]). All these psychological and psychiatric traits are linked to progressive social isolation, including avoidance of partner intimacy and isolation from family and friends, particularly at the onset of chronic pelvic pain. Thereafter, when endometriotic women have profound chronic pelvic pain (especially dyspareunia), they may even experience a greater perceived negative effect on intimate relationships, which may lead to poor psychological health [26]. In the socioeconomic context, endometriosis is associated with economic burden because a loss of productivity at work [27] and higher utilization of primary and secondary health resources [28, 29], even 10 years before being diagnosed [30] (for review, see Della Corte et al. [31]).

3.2. Polycystic Ovary Syndrome (PCOS)

In contrast to endometriotic women, which exhibit a preponderance of peripheral adipose tissue distributed below the waist (for review, see Hong and Yi [15]; for systematic review, see Backonja et al. [16]), both obese and lean PCOS women are characterized by having central adiposity (for systematic review and meta‐analysis, see [32]), WHR > 0.80, and higher probability of suffering from acne vulgaris, acanthosis nigricans, and hirsutism [33] (Table 2). Furthermore, PCOS women exhibit lower cognitive performance on memory, executive function, attention, information processing speed, and visuospatial skills (for review, see Naz et al. [34]), as well as slightly less body appreciation, including body acceptance, body respect and care, and resistance to media‐promoted appearance ideals [38], and high prevalence of anxiety and depression of different severity, although mild symptoms are more common (for systematic review and meta‐analysis, see Wang et al. [35]). PCOS women have also increased risks for eating disorders, psychosexual dysfunction, and decreased quality of life (for systematic review, see Alur‐Gupta et al. [36]). Among these risks, it is worth noting that psychosexual dysfunction is affected across multiple subdomains, including arousal, lubrication, orgasm, and pain, as well as total sexual function and sexual satisfaction. Furthermore, excess body hair has a negative effect on sexuality, sexual attractiveness, and sexual satisfaction (for systematic review and meta‐analysis, see Pastoor et al. [37]). PCOS women also display high levels of social anxiety and avoidance, mainly those women suffering from oligomenorrhea‐hirsutism and overweight‐obesity [39]. Interestingly, low socioeconomic status is associated with increased risk for PCOS [40]. This is in line with a previous publication [61] showing that PCOS women with low to medium income and low education status exhibit lower prevalence of ovulatory function compared with PCOS women with high income and high education status, respectively.

3.3. Diminished Ovarian Reserve (DOR) in Women ≪ 35 Years

Table 3 shows physical, mental, and social traits associated with DOR in women < 35 years. Żelaźniewicz et al. [41] found no significant associations between fluctuating asymmetry and levels of anti‐Müllerian hormone (AMH), a biomarker of ovarian reserve, in healthy, non‐pregnant, naturally cycling women, aged 20–28 years. In contrast, Vassena et al. [42] evidenced an association between shorter menstrual cycle lengths (< 25 days) and a lower number of growing follicles and metaphase II (MII) oocytes retrieved after controlled ovarian stimulation in oocyte donor cycles. Moreover, menstrual bleeding shorter or longer than 4–6 days was associated with lower number of retrieved MII oocytes [42]. Similarly, students, aged < 30 years, with occult primary ovarian insufficiency (POI) have shorter cycle lengths [43]. Regarding mental traits, self‐reported psychological stress is negatively associated with both antral follicular count (AFC), another biomarker of ovarian reserve, and serum AMH levels, primarily in women < 35 years compared with women ≥ 35 years [44]. This outcome is in agreement with previous studies showing that current or chronic psychological stress, and depressed symptoms are negatively associated with serum AMH levels and/or AFC in infertile women [62, 63, 64]. Furthermore, heavy smoking or smoking for a long duration may decrease ovarian reserve [65]. This finding is particularly important in the present context since smokers have lower distress tolerance (defined as the ability to withstand physical or emotional discomfort) (for systematic review and meta‐analysis, see Veilleux [66]). Therefore, both general distress and smoking may be jointly associated with decreased serum AMH levels and/or AFC. Concerning socioeconomic characteristics, AMH and AFC levels are significantly lower in women with a low socioeconomic status compared with women displaying a middle and high socioeconomic status [45, 46]. Literature also shows that there is a consistent association between socioeconomic adversity and earlier age at menopause, a proxy measure of reduced ovarian reserve (for review, see Richardson et al. [47]). Moreover, there is a weak, positive association between age at natural menopause and educational level, which is considered one of the best socioeconomic indicators (for review, see Canavez et al. [48]). However, the review by Canavez et al. [48] evidenced large methodological differences among studies, which prevented them from drawing solid conclusions.

3.4. Low Semen Quality

Table 4 shows physical, mental, personality, and social traits associated with low semen quality. Notably, the studies focused on the relationship between phenotypic traits and ejaculate quality have reported mixed results. Therefore, it is not surprising that the comprehensive review and meta‐analysis by Jeffery et al. [49] evidenced a non‐significant relationship between three combined phenotypic traits (length of the second to the fourth finger, fluctuating asymmetry, and facial attractiveness) and sperm concentration, count, and motility. More recently, Foo et al. [67] found a positive association between perceived facial masculinity and linearity of sperm movements, and a negative association between perceived facial averageness and sperm concentration and percentage of motile sperm. Thereafter, the same authors [68] reported a negative association between perceived male strength (measured as ratings of strength from full‐body photographs) and sperm concentration. In contrast, DeLecce et al. [69] found no significant associations between sperm morphology, motility, and concentration and actual handgrip strength, shoulder‐to‐hip ratio, and height. On the other hand, Joseph et al. [50] found a positive association between poorer semen volume, sperm concentration, and total sperm count and BMI, waist circumference, and weight gain since age 17 years. The study by Joseph et al. [50] endorsed previous data suggesting that overall and central adiposity are predictive of semen quality. Interestingly, men's general intelligence (estimated by a g factor extracted from five well‐validated cognitive tests evaluating broad spatial, quantitative and verbal abilities) displays a small but significant positive correlation coefficient with log sperm concentration (r = 0.15; p = 0.002), log sperm count (r = 0.19; p < 0.001), and percentage of sperm motility (r = 0.14; p = 0.002) [51]. It is important to highlight that the sample size analyzed by Arden et al. [51] (n = 425 US Vietnam‐era Army veterans, aged 31–44 years) afforded a statistical power > 80% to detect small effect sizes, that is, correlation coefficients between 0.14 and 0.19. In contrast, in a later conceptual replication study, DeLecce et al. [70] found non‐significant correlations between men's intelligence (estimated using the Raven Advanced Progressive Matrices Test‐Short Form) and sperm count, concentration, and motility. The lack of significance may be explained by the small sample size analyzed on this occasion (n = 41 men, aged 18–33 years, attending a Midwestern University in the United States). The low sample size may result in a lack of appropriate statistical power to detect the small, significant correlation coefficients found by Arden et al. [51]. Among other psychological, psychiatric, and personality traits, it is worth mentioning that extraversion, anxiety, and psychoticism are negatively associated with sperm count, morphology, motility, and vitality [52]. Similarly, raised levels of both state anxiety (it only occurs in response to stressful situations) and trait anxiety (the temperament aspect of anxiety that describes the anxiety, i.e., part of someone's personality) are associated with lower semen volume, sperm concentration and count, reduced sperm motility, and increased sperm DNA fragmentation in in‐vitro fertilization (IVF) patients [53]. Likewise, self‐reported psychological stress is associated with lower mean levels of total sperm count, normal morphology count, and number of cells with high DNA damage measured using the comet assay [54]. Lastly, semen quality may be affected by men's socioeconomic status. For instance, the use of non‐private insurance is associated with higher odds of abnormal concentration, motility, morphology, and total motile sperm count. On the contrary, higher neighborhood median income is associated with lower odds of abnormal semen parameters, specifically sperm concentration and total motile sperm count [55]. Likewise, low socioeconomic status is negatively associated with various semen parameters, including sperm concentration [56, 57, 58], total sperm count [56, 58], total motile sperm count [57, 58], and percentage of total and progressive sperm motility [58]. A recent retrospective analysis of epigenetic data [59] also suggests that sperm epigenetic patterns may vary with socioeconomic status. In particular, Stalker et al. [59] evidenced four sperm DNA differentially methylated regions that were significantly associated with lower men's self‐reported annual incomes and seven associated with lower education levels. Notably, the lowest education level was associated with a higher number of unstable promoters, suggesting dysregulation in the sperm epigenome.

4. Study Limitations

The main limitation of this study lies in the scarcity of published studies analyzing the potential associations between reproductive disorders and physical, mental, personality, and social characteristics. Another important limitation of the present study stems from the fact that, as mentioned in the Methods section, human physical and behavioral phenotypes, as well as mate choice preferences, may vary considerably among ethnic populations and cultures. Thus, the generalizability of some traits associated with the particular reproductive disorders disclosed in this study may be restricted. For instance, the pigmentary traits associated with increased prevalence of deep infiltrating endometriosis (ureteral nodule) [18] may be only circumscribed to Caucasian endometriotic women from the Mediterranean region. Finally, a cut‐off value of < 35 years was chosen to analyze the potential associations between ovarian reserve and physical, mental, and social characteristics. This cut‐off value was chosen because the negative effects of chronological ovarian aging on ovarian reserve are not yet openly manifested in women < 35 years [71]. Unfortunately, our literature search of traits linked to endometriosis, PCOS, and semen quality did not evidence studies that fulfilled this age requirement. Such a constraint is particularly important for mental disorders since it is not yet known how much mental disorders affects women/men fertility and how much being aware of being infertile contributes to mental health (for systematic review, see Szkodziak et al. [72]). In any case, it should be borne in mind that couples usually form at a young age when women/men are not yet aware of their real reproductive potential.

5. Overall Results

This article discloses emerging data showing that endometriosis and PCOS display opposite physical traits. Whereas endometriosis is associated with lower BMI and WHR, PCOS is linked to central adiposity and WHR > 0.80 in both obese and lean women. Endometriosis is also associated with severe teenage acne, red hair, fair skin, nevi and freckles, light eyes, and high sensitivity to sun exposure, while PCOS is associated with acne vulgaris, acanthosis nigricans, and hirsutism in both obese and lean women. In the psychological and psychiatric sphere, PCOS is related to lower cognitive performance on memory, executive function, attention, information processing speed, and visuospatial skills. DOR in women < 35 years is associated with shorter cycle length and menstrual bleeding length, either shorter or longer than 4‐6 days. Special mention should be made of the modest but significant positive correlation between sperm quality and men's general intelligence. On the contrary, sperm quality is negatively associated with BMI, waist circumference, weight gain since age 17 years, extraversion, and psychoticism. Notably, the four reproductive disorders analyzed in this study are significantly associated with high levels of anxiety, stress, and/or depression, as well as economic burden (endometriosis) or lower socioeconomic status (polycystic ovary syndrome, DOR, and low semen quality).

The sexual selection process experienced by women/men when seeking a reproductive partner, proposed by the hypothesis on the origin of infecundity [1], would result in a gradient of couples displaying different reproductive potentials. Couples with maximum and minimum reproductive potential would represent the extremes of this gradient. Between these extremes, there would be myriads of combinations of couples with either a single member of the pair or the two members of the pair exhibiting decreased reproductive potential. According to our hypothesis, once a mate choice decision has been made, those couples displaying preferred traits would have an advantage over couples exhibiting less preferred traits in achieving a spontaneous pregnancy and live birth. As a result of this sexual selection process, couples with less preferred physical, mental, personality, and/or social traits may eventually seek infertility treatment. Notably, this selective process may, at least in part, account for (1) the relative low efficacy of ART treatments (for review, see Tarín et al. [71]); and (2) the adverse pregnancy, perinatal, and childhood complications associated with subfertility/infertility factors (for reviews, see Palomba et al. [73], Vannuccini et al. [74].

6. Conclusion and Future Prospects

The present study discloses specific physical, mental, personality, and social traits associated with four reproductive disorders. The original publications analyzed include women and men from different geographic origins (e.g., the United States, Canada, Italy, Germany, Holland, Denmark, Finland, Poland, Spain, Turkey, India, and Australia) and diverse ethnicities (e.g., white non‐Hispanic, black non‐Hispanic, Hispanic, Asian, Turkish, and Caucasian). The varied geographic origins and ethnicities found in the literature suggest that more efforts are warranted to evaluate traits associated with these and other reproductive disorders, using a multiethnic and multicultural perspective. This comprehensive analysis may enable us to have a comparative viewpoint of how sexual selection acts in different ethnic populations and cultures.

It is also important to remark that the four reproductive disorders analyzed in the present study are associated with high levels of anxiety, stress, and/or depression. Moreover, these conditions, especially endometriosis and PCOS, are linked to decreased quality of life, body image disturbance, psychosexual dysfunction, and functional limitations in social roles. These non‐physical, functional traits are critical factors in the overall well‐being and life participation of the individuals. Thus, it is essential for patients with these reproductive disorders to undergo psychosocial screenings and multi‐disciplinary, holistic interventions. Health professionals should provide appropriate personalized care to these patients to improve their quality of life.

Author Contributions

Juan J. Tarín: conceptualization (lead), formal analysis (equal), investigation (lead), methodology (lead), visualization (lead), writing – original draft preparation (lead), writing– review and editing (equal). Miguel Ángel García‐Pérez: formal analysis (equal), writing – review and editing (equal). Antonio Cano: formal analysis (equal), writing – review and editing (equal). All authors revised the article critically for important intellectual content, approved the final version to be published, and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Funding

The authors received no specific funding for this work.

Conflicts of Interest

The authors declare no conflicts of interest.

Transparency Statement

The lead author, Juan J. Tarín, affirms that this manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.

Data Availability Statement

Data sharing not applicable to this article as no data sets were generated or analyzed during the current study.