Multiple sex partners (MSP) is the measure and incidence of engaging in sexual activities with two or more people within a specific time period. The sexual partners can be of any number, sex, gender, or sexual orientation. MSP can also mean that one person may have a long-term relationship or relationships, and when the second relationship begins, the person can be said to have multiple sex partners.

The MSP for adolescents has been quantified with the following descriptions:

  • never having had sexual intercourse (no MSP)
  • having multiple sex partners, defined as having had four or more sex partners during one's lifetime
  • sexual activity was defined as having had sexual intercourse during the past 3 months
  • some clinicians define MSP by also taking into account concurrent sexual relationships

Intimate relationships with more than one partner include:


Another term, polyamoruous, is the practice of or desire for intimate relationships with more than one partner, with the knowledge of all partners. It has been described as "consensual, ethical, and responsible non-monogamy" (Pic. 1). People who identify as polyamorous reject the view that sexual and relational exclusivity are necessary for deep, committed, long-term loving relationships.

Polyamory is not illegal and is not bound by religion, nor is bound by group sex or even being promiscuous in general. Some polyamorous individuals may or may not engage in sexual encounters with their partners. Individuals in a polyamorous relationship can also experience the same longevity, fulfilment and satisfaction as those in monogamous relationships.

Polyamorous relationships are characterised as being non-exclusive, committed relationships (mutual agreement between a couple and not just one partner making all the decisions). Polyamory is not synonymous with infidelity because infidelity is what occurs in couples who break an agreement to have an exclusive and committed partnership. Polyamory also differs from open relationships in the sense that open relationships are characterised as being non-exclusive and non-committed. Although the two relationship types somewhat intertwine, open relationships tend to be more casual with less emphasis on commitment. The main principal of polyamory is that ""poly" individuals are committed to being open about each of their relationships present in their lives". Polyamorous individuals generally have one or more primary partners whom they are committed to and may have other partners whom they are intimate with on some occasions.


Polygamy is the practice of marrying multiple spouses. When a man is married to more than one wife at a time, sociologists call this polygyny. When a woman is married to more than one husband at a time, it is called polyandry. If a marriage includes multiple husbands and wives, it can be called a group marriage.

Polygamy also negatively affects the relationship between children and their mothers, with the former resenting the mother for being unable to make sure the father does not neglect them or for becoming depressed and also neglecting their emotional needs. Regardless of gender, they lack of confidence in their own ability to have stable relationships because they have only experienced a family life filled with traumatic quarrels and resentment. The children of second wives usually cope better because from birth they know their father has another family. But the children from the first family can see the comparison: the lack of time, lack of resources, their father’s absence when they needed him.

A social history is the part of a medical exam addressing familial, occupational, and recreational aspects of the patient's personal life that have the potential to be clinically important. MSP is only the description of the behavior described in clinical terms. Promiscuity can mean that a moral judgement is made because some parts of societies promote sexual activity to occur only within exclusive, single-partner, committed relationships. is often the way researchers define a society's promiscuity levels at any given time. 

The impact of polygamy on women has both economic and emotional aspects. The research has found that many men in both lower and middle economic groups marry second wives so that they will contribute to the economic maintenance of their polygamous families.

More lifetime partners is associated with an increased risk of sexually transmitted infections (STIs). Sexually transmitted diseases (STD) are infections transmitted mainly through sexual contact. Over 30 different types of bacteria, viruses and parasites are sexually transmitted, with the most common STD being gonorrhea, chlamydia, syphilis, trichomoniasis, chancroid, genital herpes, genital warts, human immunodeficiency virus (HIV) and hepatitis B. One can get an STD from having sexual activity that involves the mouth, anus, vagina, and penis. Not all STIs are symptomatic, and symptoms may not appear immediately after infection. In some instances a disease can be carried with no symptoms, which leaves a greater risk of passing the disease on to others. Depending on the disease, some untreated STIs can lead to infertility, chronic pain or even death.


Multiple partnership means those who have had sexual intercourse with more than one partner in the past 12 months.

Associated diseases

  • sexually transmitted diseases (STDs)
  • HIV infection
  • human papillomavirus (HPV)


MSP increases the risk of many diseases and other conditions. Sexually transmitted diseases (STDs) are known to cause complications in pregnancy including miscarriage, preterm labour and still birth. Some STDs can also have a significant effect on the morbidity and mortality of the neonate. However, the effect of these infections on male fertility is less clear.

Having multiple sex partners is a significant behavioral risk factor for HIV/STDs. Adolescents typically engage in short-lived relationships that make them more likely than adults to have sex with multiple partners, thereby placing them at greater risk for contracting HIV/STDs. As the number and variety of new sex partners increases, so does the risk of exposure to individuals infected with STDs. The presence of an STD greatly increases a person's likelihood of acquiring or transmitting HIV through sexual contact. Most importantly, those who have multiple sex partners are less likely to use condoms during sex.

Risk factors

  • adolescences and young adults
  • casual sexual partners
  • alcohol consumption
  • drug use
  • concurency behavior


In addition to increasing health as a preventive policy, education is a protective factor. Safe sexual behaviors include having a single sex partner and using condoms in every sexual encounter, and these behaviors also reduce risk of HIV/STDs.

Female fertility

The risk of adverse health outcomes from multiple sex partners is greater for females than males, as it has direct influence on reproductive health. Untreated STDs may make females susceptible to cervical dysplasia (abnormal cells on the surface of the cervix) and pelvic inflammatory disease (PID), which can lead to infertility, ectopic (tubal) pregnancies (EP), and compromised fetal health. 

Pelvic inflammatory disease (PID), a complication of chlamydia and gonorrhoea, is associated with female tubal infertility. PID can cause scarring and damage which can affect fertility. If both or one of the fallopian tubes are blocked due to scars and adhesions, then the sperm will not reach egg and egg cannot make way to the uterus. This prevents fertilization and also pregnancy. If only one fallopian tube in blocked, there is yet a possibility that a woman can get pregnant, since the other tube can release an egg and let a sperm swim through. Two blocked fallopian tubes, however, are not a good sign for women who wish to naturally become pregnant. Untreated PID can result in long term complications including ectopic pregnancy and infertility.

Surgical treatment for EP includes salpingectomy (surgical removal of a fallopian tube), salpingostomy (creation of an opening into the fallopian tube, but the tube itself is not removed) and tubal anastomosis (unblocking of the fallopian tubes). 

Tubal anastomosis restores patency of the fallopian tubes after sterilisation, in patients who wish to become pregnant. First, a tubal surgery scar after tubal anastomosis can easily cause stenosis and tubal blockage, which interferes with sperm fertilisation of eggs in the fallopian tube, resulting in blastocyst (early developmental structure) formation in the fallopian tube. Thus, there would be a lower intrauterine pregnancy rate and higher recurrence of EP after tubal anastomosis. Second, other potential risk factors may produce these results. In summary, the mechanisms of lower intrauterine pregnancy rate and higher EP recurrence after tubal anastomosis are still unclear and further study is needed.

Adolescent girls who have multiple partners may also be vulnerable to dating violence.

Male fertility

In addition to any physical effect, the psychological effect of having an STI may also have an adverse impact on both male sexual function and fertility and therefore should not be overlooked. Specifically, psychological stress is common in patients with prostatitis (inflammation of prostate). 43% of men with symptomatic prostatitis complain of erectile dysfunction and 24% report low libido, thus adversely affecting the ability to conceive.

The history of multiple partners may be associated with sexually transmitted infections. Prognosis of STIs varies greatly depending on the disease and treatment. The STIs that can affect fertility and/or neonatal health include Chlamydia, gonorrhoea, human immunodeficiency virus (HIV), genital herpes, syphilis and Mycoplasma genitalium. 

Most STIs are treatable or curable. Of the most common infections, syphilis, gonorrhea, chlamydia, trichomoniasis are curable, while herpes, hepatitis B, HIV/AIDS, and HPV are treatable but not curable. Resistance to certain antibiotics is developing among some organisms such as gonorrhea.

Untreated Chlamydia causes tubal infertility and ectopic pregnancy in women and urethritis, prostatitis (inflammation of urethra, prostate or epididy and epididymis) that impair sperm quality and fuction in men. Untreated gonorrhoea Mycoplasma genitalium leads to pelvic inflammatory disease (PID) in both men and women. PID increases the risk of blockage of the fallopian tubes and thus increases the risk of ectopic pregnancy. Genital herpes does not affect the pregnancy at all, but it could be transmitted to the baby during delivery.

HIV infected women may have decreased reproductive potential in terms of ovarian response to stimulation, fertilization, and implantation. Additionaly, there is a higher risk of concomitant sexually transmitted diseases that are known to contribute to tubal blockage. Biological changes caused by HIV, including systemic illnesses, stress, and weight loss, may affect the function of reproductive organs and result in infertility. Newly diagnosed HIV infection may cause psychological trauma and decrease in sexual drive and sexual activity. Additionaly, there is a high risk of congenital HIV for baby and thus assisted reproductive techniques (ART) treatment is highly recommended for HIV patients.

If the syphilis is treated (especially in early stages), there are no trouble conceiving or carrying a baby due to previous infection. If the syphilis persists, there is a high risk that the infection passes from the mother to the child through the placenta or during the delivery. 


Sexually transmitted infection ―sourced from Wikipedia licensed under CC BY-SA 3.0
Sexual partner ―sourced from Wikipedia licensed under CC BY-SA 3.0
Polyamory ―sourced from Wikipedia licensed under CC BY-SA 3.0
Sexually transmitted diseases ―sourced from Fertilitypedia licensed under CC BY-SA 4.0
Polygamy ―sourced from Wikipedia licensed under CC BY-SA 3.0
Multiple sex partners ―sourced from Wikipedia licensed under CC BY-SA 3.0
Gonorrhea ―Spillane licensed under CC BY-SA 3.0
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