Deep Research Archives

A Clinical and Scientific Analysis of the Disadvantages and Risks Associated with Sexual Intercourse During Menstruation

Introduction

Sexual activity during menstruation is a common practice and a matter of personal comfort and choice for many couples.1 From a physiological perspective, some potential benefits have been reported in both popular literature and some clinical observations. These include potential relief from menstrual cramps (dysmenorrhea), which may be mediated by the uterine contractions and subsequent release of tension following orgasm. Additionally, the presence of menstrual blood can serve as a natural lubricant, potentially increasing comfort and pleasure, while hormonal shifts during this phase may lead to a heightened libido for some individuals.1 While acknowledging these potential benefits, a comprehensive understanding of sexual health requires an objective, evidence-based examination of the potential disadvantages and health risks for both female and male partners. This report provides an exhaustive, scientific analysis of these risks. The focus is not on personal preference but on the documented physiological, microbiological, and pathological changes that occur during menstruation and how these changes can create a window of heightened vulnerability to infection and other adverse health outcomes. This analysis will delve into the underlying mechanisms of risk, critically evaluate the existing medical literature—highlighting both well-established risks and areas of scientific controversy—and provide a clear framework for understanding the potential health consequences associated with this practice.

Section 1: The Female Reproductive Tract During Menstruation: A State of Heightened Vulnerability

The potential health risks associated with sexual intercourse during menstruation are not arbitrary; they are rooted in a series of concurrent physiological changes that temporarily compromise the female reproductive tract's natural defense mechanisms. This section details a triad of key changes—a compromised cervical barrier, a disrupted vaginal microenvironment, and modulated local immunity—that collectively create a state of heightened biological vulnerability.

1.1 The Compromised Cervical Barrier: An Open Gateway

Under normal circumstances, the cervix—the lower, narrow end of the uterus that opens into the vagina—acts as a formidable barrier protecting the sterile upper genital tract (the uterus, fallopian tubes, and ovaries) from the microbe-rich environment of the vagina.5 This defense is both physical and immunological. The cervical opening, or os, is typically narrow and sealed by a thick, viscous mucus plug that is difficult for bacteria to penetrate.7 During menstruation, this barrier undergoes significant physiological changes to serve its primary function: allowing the outflow of menstrual blood and shed endometrial tissue. The cervix softens, may descend lower into the vaginal canal, and, most critically, the external os dilates slightly.9 While this dilation is a necessary part of the menstrual process, it temporarily compromises the cervix's effectiveness as a gatekeeper.7 The clinical significance of this temporary breach is profound. It creates a more permissive pathway for microorganisms to ascend from the lower genital tract into the uterus and beyond. This mechanism of "ascending infection" is the central pathophysiological event in the development of serious conditions like Pelvic Inflammatory Disease (PID).5 The Mayo Clinic explicitly notes that the normal barrier created by the cervix is disturbed during menstruation, creating an opportunity for bacteria to enter the upper reproductive tract.7 When sexual intercourse occurs during this time, the mechanical action of penile thrusting can act as a vector, potentially propelling pathogens from the vagina directly toward and through this temporarily open gateway.

1.2 Alterations in the Vaginal Microenvironment: A Disruption of Chemical Defenses

The vagina's primary defense against infection is chemical. A healthy vaginal ecosystem maintains a distinctly acidic pH, typically ranging from 3.8 to 4.5.12 This acidity is not passive; it is actively maintained by a dominant community of beneficial bacteria, primarily of the genus Lactobacillus. These microorganisms metabolize glycogen from vaginal epithelial cells to produce lactic acid and other antimicrobial compounds, such as hydrogen peroxide, which actively suppress the growth of pathogenic bacteria and yeast.15 This delicate chemical balance is significantly disrupted during menstruation. Menstrual blood is not acidic; it has a neutral to slightly alkaline pH of approximately 7.4, similar to that of blood elsewhere in the body.15 The sustained presence of this alkaline fluid in the vaginal canal for several days temporarily neutralizes the vagina's protective acidity, causing the overall vaginal pH to rise.1 The microbiological consequences of this pH shift are immediate and significant. The less acidic environment suppresses the growth of the protective Lactobacilli and simultaneously creates a more favorable milieu for the proliferation of other microorganisms, particularly the anaerobic bacteria associated with bacterial vaginosis (BV) (e.g., Gardnerella vaginalis) and yeast (Candida albicans).3 This state of microbial imbalance, known as dysbiosis, increases the risk of local infections like yeast infections and BV. More critically, in the context of ascending infection, it means that a higher concentration of potentially pathogenic microbes may be present in the vagina, ready to be transported into the upper genital tract through the compromised cervical barrier.16

1.3 Immunological Fluctuations and Systemic Changes

The immune system's activity within the female genital tract is not static but fluctuates rhythmically in response to the hormonal cascade of the menstrual cycle.18 In the latter half of the cycle (the luteal phase), rising progesterone levels naturally suppress the local immune response. This is a crucial adaptation to prevent the immune system from attacking a potential embryo and to allow for implantation.18 The process of menstruation itself is a highly orchestrated inflammatory event required to shed the uterine lining.18 However, the overall immune posture during this time is complex. Some evidence suggests that the body's innate immune response may be hampered, potentially contributing to an increased susceptibility to certain sexually transmitted infections (STIs).19 This altered immune state, combined with the compromised physical and chemical barriers, completes the triad of vulnerability. Furthermore, menstrual blood itself, being rich in iron and other nutrients, can act as a culture medium, further promoting the growth of certain bacteria that thrive in such conditions.16 The confluence of a breached physical barrier (dilated cervix), a neutralized chemical defense (elevated pH), a rich microbial food source (blood), and a potentially modulated immune response creates a synergistic "perfect storm." This combination of factors establishes a unique window of biological opportunity for pathogens that does not exist at other points in the menstrual cycle, providing the foundational rationale for the specific risks discussed in the following sections.

Section 2: Ascending Infections and Inflammatory Conditions in the Female Partner

The state of heightened vulnerability in the female reproductive tract during menstruation creates a plausible pathway for the development of serious inflammatory and infectious conditions. The mechanical action of intercourse during this period can potentially facilitate the ascent of microorganisms, leading to conditions with significant long-term health consequences. This section examines the evidence, including areas of scientific debate, surrounding the risk of Pelvic Inflammatory Disease and endometriosis.

2.1 Pelvic Inflammatory Disease (PID): An In-depth Analysis

Pelvic Inflammatory Disease is an infection and inflammation of the upper female genital tract, an umbrella term that can include endometritis (infection of the uterine lining), salpingitis (infection of the fallopian tubes), and oophoritis (infection of the ovaries).5 The disease is nearly always the result of an ascending infection, where microorganisms travel from the vagina and cervix into the upper reproductive organs.5 The most common causative agents are the sexually transmitted bacteria Neisseria gonorrhoeae and Chlamydia trachomatis, which are responsible for the majority of cases.5 However, a polymicrobial infection involving organisms associated with bacterial vaginosis is also frequently implicated.5 The scientific literature presents a nuanced and somewhat contested view on whether sexual intercourse during menstruation is an independent risk factor for developing PID. A strong argument for an association is rooted in biological plausibility. As established, menstruation provides a clear opportunity for bacterial ascent due to the open cervix.7 Some research has explicitly identified a link. One notable case-control study conducted at San Francisco General Hospital found that having sex during the previous menstrual period was a significant risk factor for symptomatic PID, increasing the odds by more than five times (odds ratio 5.22).23 Other sources also state that a woman's risk for developing PID from an existing gonorrhea or chlamydia infection is higher when she is menstruating.24 The theory is that uterine contractions during intercourse, combined with the physical act of penetration, could facilitate the upward transport of these pathogens.25 Conversely, other studies have failed to find a significant link. An earlier study published in 1989 investigated coital habits and found no statistically significant difference in the frequency of PID between women who engaged in menstrual coitus (10.8%) and those who did not (9.7%).27 A more recent review article from 2010 also concluded that intercourse during menses is "probably not associated with increased risk for pelvic inflammatory disease".19 This apparent contradiction in the literature may be resolved by moving beyond a simple cause-and-effect model. The single most important risk factor for PID is the presence of an underlying, untreated STI.5 Many of these infections, particularly chlamydia, are often asymptomatic in women, who may be unaware they are infected.28 Therefore, it is likely that menstrual coitus is not a primary cause of PID in a healthy, uninfected woman. Instead, it acts as a potent facilitator or risk amplifier. In a woman who already has an undiagnosed lower genital tract infection, the physiological changes of menstruation create the ideal conditions for that infection to ascend, and the mechanical action of intercourse may provide the final push. This explains why some studies find a correlation—the behavior is a trigger in those already at risk—while others do not, especially if the study population has a low prevalence of underlying STIs. The gravity of this risk lies in the severe and often irreversible long-term sequelae of PID. Even a single episode of the disease can cause significant scarring (adhesions) of the delicate fallopian tubes. This scarring can lead to devastating complications, including chronic pelvic pain, which affects up to 18% of women post-PID; a dramatically increased risk of ectopic (tubal) pregnancy, a life-threatening condition; and infertility, which can affect 10-20% of women who have had PID.7

2.2 The Risk of Endometriosis: A Review of Competing Theories

Endometriosis is a chronic, inflammatory condition characterized by the growth of tissue similar to the uterine lining (endometrium) in locations outside of the uterus, most commonly on the ovaries, fallopian tubes, and the pelvic peritoneum.30 The most widely accepted theory for its pathogenesis is retrograde menstruation. This theory posits that during menstruation, some menstrual blood containing viable endometrial cells flows backward through the fallopian tubes and into the pelvic cavity, instead of exiting the body through the vagina.30 While up to 90% of women are believed to experience some degree of retrograde flow, it is thought that in women who develop endometriosis, there is either an unusually high volume of reflux or a problem with the immune system's ability to recognize and clear these displaced cells, allowing them to implant and grow.33 The potential link between sexual activity during menstruation and endometriosis is one of the most debated topics in gynecology. The central hypothesis is that the powerful uterine contractions associated with orgasm could enhance the volume of retrograde menstrual flow, thereby "seeding" more endometrial cells into the pelvis and increasing the risk of developing the disease.34 The epidemiological data on this topic is profoundly contradictory. Several studies have found evidence supporting an increased risk. An early study reported a higher frequency of surgically confirmed endometriosis among women who had intercourse during menstruation (17.5%) compared to those who did not (10.9%).27 A more recent Iranian case-control study similarly concluded that the occurrence of endometriosis was "significantly higher" in women who reported sexual activities leading to orgasm during their period.35 A study from Qatar found the incidence of endometriosis to be 66% in patients with a history of coitus during menses, versus 34% in those without.33 Furthermore, a systematic review and meta-analysis of available studies suggested an approximately two-fold higher probability of having sexual activity during menstruation in women with endometriosis compared to controls.36 In stark contrast, other research has suggested the opposite effect. A notable case-control study from Yale University found that women with endometriosis were significantly less likely to engage in sexual behaviors during menstruation, leading the authors to hypothesize that such activity might confer a protective effect.37 The proposed mechanism for this protection is that intercourse and orgasm might facilitate the anterograde (forward) flow and expulsion of menstrual debris, thereby reducing the amount of retrograde flow. Given these diametrically opposed findings, the medical community has not reached a consensus. No definitive clinical recommendation can be made regarding sexual activity during menstruation as a risk factor for endometriosis.34 The relationship remains theoretical and is an area of active and ongoing research. The conflicting evidence underscores the complexity of endometriosis pathophysiology, which is likely multifactorial and may be influenced more significantly by genetic predisposition, immune function, and hormonal factors than by any single behavior.

Section 3: Pathogen Transmission and Risks for the Male Partner

While much of the focus on risks associated with menstrual coitus centers on the female partner's internal physiology, there are significant and well-documented risks for the male partner as well. These risks are primarily related to the direct transmission of pathogens, with menstrual blood acting as a potent vehicle for certain infectious agents.

3.1 Transmission of Blood-Borne Viruses

The most serious risk for a male partner is the transmission of blood-borne viruses. Menstrual effluent is not merely vaginal fluid; it is composed largely of blood and tissue from the uterine lining. Consequently, if the female partner is living with a blood-borne viral infection, the virus will be present in her menstrual blood.9 During unprotected intercourse, this infected blood can come into direct contact with the mucous membranes of the male urethra or enter the male partner's bloodstream through any micro-abrasions or open sores on the penis, hands, or mouth, providing a clear and efficient route for transmission.39 Specific pathogens of concern include: Human Immunodeficiency Virus (HIV): If a woman is living with HIV and has a detectable viral load, the virus can be transmitted through contact with her menstrual blood.38 The risk of transmission is present, and some data even suggests that the concentration of HIV in cervical fluids may be higher just before and during the menstrual period, potentially increasing the transmissibility of the virus at this time.41 Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV): Both of these viruses cause serious liver disease and are transmitted through blood-to-blood contact. As such, they can be efficiently transmitted via exposure to infected menstrual blood during sexual activity.1 It is clinically imperative to contextualize this risk with the modern understanding of viral treatment, particularly for HIV. The principle of Undetectable = Untransmittable (U=U) is a paradigm-shifting public health message. It means that if a person living with HIV is on effective antiretroviral therapy (ART) and has maintained a durably undetectable viral load for at least six months, there is effectively zero risk of sexually transmitting the virus to a partner.41 Therefore, the risk of HIV transmission via menstrual blood is not absolute but is conditional upon the female partner's treatment status and viral suppression. This U=U principle, however, does not apply to other STIs like Hepatitis, chlamydia, or gonorrhea.

3.2 Risk of Urethritis and Fungal Infections (Balanitis)

Beyond viral pathogens, the altered vaginal environment during menstruation can facilitate the transmission of other microorganisms that can cause localized infections in the male partner. Balanitis: This condition is an inflammation of the glans (head) of the penis.43 A common cause is an overgrowth of the fungus Candida, transmitted from a female partner who has a vaginal yeast infection (candidiasis). As previously discussed, the elevated vaginal pH during menstruation can make a woman more prone to a yeast infection flare-up.3 Intercourse can then transfer this fungal overgrowth to the male partner, resulting in balanitis.3 Symptoms include redness, itching, a burning sensation on the penis, and potentially a thick, white, clumpy substance collecting in skin folds, particularly under the foreskin.39 Being uncircumcised is a significant risk factor for developing balanitis, as the foreskin can trap moisture and create an environment where yeast can thrive.43 Urethritis: This is an inflammation of the urethra, the tube through which urine exits the body. It can be caused by the same bacteria responsible for common STIs, such as Chlamydia trachomatis and Neisseria gonorrhoeae. If the female partner has one of these infections, the male partner is at risk of contracting it, and the presence of blood may serve as an additional medium for this transmission, potentially leading to symptoms like painful urination and penile discharge.39 The risk to the male partner is therefore not from menstrual blood itself, which is sterile upon leaving the uterus, but from the pathogens it may contain or that may be co-present in the vagina. The menstrual state changes the nature of the fluid exchange during sex, adding blood as a vehicle for certain viruses and creating a vaginal environment that can promote the growth of other organisms, like yeast, which can then be transmitted.

Section 4: General Risks and Practical Considerations

In addition to the specific risks for each partner, sexual activity during menstruation carries several general risks and practical considerations that are applicable to the couple as a unit. These risks are amplified by the unique physiological context of the menstrual period.

4.1 Globally Increased Risk of Sexually Transmitted Infection (STI) Exchange

The factors outlined in the preceding sections create a synergistic effect that increases the efficiency of STI transmission in both directions, making menstruation a period of heightened risk for both partners. From Male to Female: The woman's natural defenses are lowered. The elevated vaginal pH makes her more susceptible to colonization by pathogens introduced by her partner, and the open cervix provides a direct route for these pathogens to cause a more serious ascending infection like PID.6 An inflamed cervix (cervicitis), which can be caused by STIs, may also let viruses and bacteria enter the bloodstream more easily.45 From Female to Male: As established, menstrual blood acts as a potent transmission medium for any blood-borne pathogens (HIV, Hepatitis) or other STIs located in the cervix or blood (e.g., syphilis) that the woman may have.24 The risk of transmitting infections like HIV, hepatitis, and herpes is increased during this time.1 Essentially, the physiological state of menstruation creates an environment more conducive to infection exchange. For this reason, the use of barrier methods such as condoms is of critical importance during this time to mitigate the risk of transmitting a wide range of STIs.2

4.2 The Risk of Unintended Pregnancy

One of the most persistent myths surrounding sexual health is that a woman cannot become pregnant while she is menstruating. This is unequivocally false.1 While the likelihood of conception is significantly lower during the menstrual period compared to the fertile window surrounding ovulation, a tangible risk of pregnancy still exists.4 This risk is a function of two independent biological variables: Sperm Viability: Sperm are remarkably resilient and can survive within the female reproductive tract for up to five days after ejaculation.3 Variable Ovulation Timing: The "textbook" 28-day menstrual cycle with ovulation on day 14 is an average, not a universal rule. Many women have shorter cycles (e.g., 21 to 24 days), and ovulation can occur much earlier than anticipated, sometimes just a few days after menstruation ends.4 These two factors create a scenario for potential conception. For example, if a woman with a short cycle has unprotected intercourse toward the end of her period (e.g., on day 6), sperm can survive in her reproductive tract. If she then ovulates early (e.g., on day 10 or 11), the sperm deposited four or five days prior can still be viable and present to fertilize the newly released egg.46 For this reason, menstruation should never be relied upon as a method of contraception. Reliable birth control methods are essential for preventing unintended pregnancy, regardless of the phase of the menstrual cycle.

4.3 Mechanical and Foreign Body Risks: The Forgotten Tampon

Beyond microbiological and reproductive risks, there is a significant mechanical risk associated with intercourse during menstruation: the retained tampon. It is imperative that a tampon be removed before any form of penetrative vaginal intercourse.1 If a tampon is left in place, the action of intercourse can push it deep into the vaginal canal, often into the posterior fornix, which is the recess behind the cervix. Once lodged in this position, it can become extremely difficult or impossible for the woman to locate and retrieve it herself.1 A retained tampon is a serious medical concern. It becomes a breeding ground for bacteria, leading to a foul-smelling vaginal discharge, pelvic pain, and potentially an overgrowth of Staphylococcus aureus, which can cause Toxic Shock Syndrome (TSS). TSS is a rare but life-threatening complication characterized by high fever, rash, and organ dysfunction. A retained tampon almost always requires medical intervention for removal.1 This risk is entirely preventable through awareness and simple hygienic practice but represents a severe potential consequence of an oversight.

Section 5: Conclusion and Clinical Recommendations

The decision to engage in sexual activity during menstruation is a personal one, influenced by individual comfort, relationship dynamics, and cultural norms. However, from a clinical and scientific standpoint, this practice is associated with a distinct set of health risks rooted in the temporary physiological changes of the female reproductive tract. A comprehensive understanding of these risks is essential for all sexually active individuals to make informed decisions that safeguard their health and the health of their partners. The evidence indicates that during menstruation, the female body enters a state of heightened vulnerability. A combination of a physically open cervix, a neutralized vaginal pH, and the presence of blood as a microbial culture medium creates a synergistic environment that increases the efficiency of pathogen exchange and the potential for ascending infection. The following table summarizes the key health risks and the strength of the scientific evidence supporting the association with menstrual coitus. Table 1: Summary of Evidence on the Association Between Menstrual Coitus and Specific Health Risks

Health Risk Proposed Mechanism Strength of Scientific Evidence Key Research Findings & Citations Pelvic Inflammatory Disease (PID) Ascent of pathogens (STIs, BV-associated microbes) through a compromised cervical barrier, potentially facilitated by uterine contractions from intercourse. Conflicting The risk is biologically plausible.7 Some studies show a strong statistical association 23, while others find no significant link.19 The risk is most likely not from menstrual coitus alone but is significantly amplified in the presence of an underlying, untreated STI. Endometriosis Uterine contractions during orgasm enhance the retrograde flow of menstrual blood and endometrial cells into the pelvic cavity. Highly Conflicting Studies have produced diametrically opposed results. Some suggest an increased risk 33, while others suggest a protective effect or no association.37 The link remains theoretical and is not clinically proven. Blood-Borne Virus Transmission (HIV, HBV, HCV) to Male Partner Direct contact of the male urethra or micro-abrasions with infected menstrual blood, which acts as a transmission vehicle. Strong Menstrual blood is a bodily fluid capable of transmitting these viruses.38 The risk for HIV is conditional on the female partner's viral load and is effectively eliminated if she is on treatment and has an undetectable viral load (U=U).41 Bacterial/Yeast Infection Exchange (Both Partners) Altered vaginal pH during menses increases female susceptibility to yeast infections and BV.9 These can be transmitted to a male partner, potentially causing balanitis.3 Moderate to Strong The physiological basis of the pH change is well-established. The transmission of yeast causing balanitis is clinically documented. Menstruation creates a favorable environment for certain infections in the woman, which can then be exchanged. Unintended Pregnancy Survival of sperm (up to 5 days) in the reproductive tract combined with variable ovulation timing, particularly in women with short cycles. Moderate The risk is lower than mid-cycle but is biologically plausible and documented.4 It is not a reliable "safe period."

Clinical Recommendations for Risk Mitigation

Based on the available evidence, the following clinical best practices are recommended to mitigate the health risks associated with sexual intercourse during menstruation: Consistent Use of Barrier Methods: The consistent and correct use of condoms is the single most effective strategy to reduce the majority of the identified risks. Condoms provide a physical barrier that prevents the exchange of bodily fluids, thereby reducing the transmission of STIs (including blood-borne viruses like HIV and Hepatitis), blocking the ascent of bacteria that could lead to PID, and preventing unintended pregnancy.2 Open Communication and Regular STI Testing: Honest communication between partners about sexual history and STI status is a fundamental component of sexual health. Given that many STIs are asymptomatic, regular screening for all sexually active individuals is crucial for early detection and treatment. Treating existing infections is the most effective way to prevent transmission and to reduce the risk of long-term complications like PID.7 Awareness of HIV Status and Treatment (U=U): For couples where one partner is living with HIV, understanding and discussing the U=U principle is essential for accurately assessing transmission risk. Effective antiretroviral therapy that leads to a sustained undetectable viral load prevents the sexual transmission of HIV.41 Hygienic Practices: It is critical to ensure a tampon is always removed prior to penetrative intercourse to avoid the serious risk of a retained tampon and subsequent infection.1 In conclusion, while the choice to have sex during menstruation is personal, it is not without potential health consequences. An understanding of the underlying physiological changes and the associated, evidence-based risks empowers individuals and couples to make informed decisions, utilize protective measures, and engage in practices that prioritize their long-term sexual and reproductive health. 참고 자료 Sex on Your Period: Side Effects, Benefits, and Safety, 8월 2, 2025에 액세스, https://www.verywellhealth.com/sex-during-your-period-2721991 Is It OK to Have Sex While You Have Your Period? (for Teens) | Nemours KidsHealth, 8월 2, 2025에 액세스, https://kidshealth.org/en/teens/sex-period.html Sex during menstruation: Safety, can you get pregnant, and benefits, 8월 2, 2025에 액세스, https://www.medicalnewstoday.com/articles/321667 Sex During Periods: Benefits, Side Effects, Pregnancy Risk - Healthline, 8월 2, 2025에 액세스, https://www.healthline.com/health/womens-health/sex-during-periods Pelvic Inflammatory Disease - StatPearls - NCBI Bookshelf, 8월 2, 2025에 액세스, https://www.ncbi.nlm.nih.gov/books/NBK499959/ Cervicitis - Symptoms and causes - Mayo Clinic, 8월 2, 2025에 액세스, https://www.mayoclinic.org/diseases-conditions/cervicitis/symptoms-causes/syc-20370814 Pelvic inflammatory disease (PID) - Symptoms & causes - Mayo Clinic, 8월 2, 2025에 액세스, https://www.mayoclinic.org/diseases-conditions/pelvic-inflammatory-disease/symptoms-causes/syc-20352594 Pelvic Inflammatory Disease (PID): Symptoms & Treatment - Cleveland Clinic, 8월 2, 2025에 액세스, https://my.clevelandclinic.org/health/diseases/9129-pelvic-inflammatory-disease-pid Period Sex: What You Should Know About Safety, Benefits, and Risks - Everyday Health, 8월 2, 2025에 액세스, https://www.everydayhealth.com/news/it-safe-have-sex-during-your-period/ Cervix Before Period: How to Check, Changes Throughout Cycle, More - Healthline, 8월 2, 2025에 액세스, https://www.healthline.com/health/cervix-before-period Pelvic Inflammatory Disease (PID) - Gynecology and Obstetrics - Merck Manuals, 8월 2, 2025에 액세스, https://www.merckmanuals.com/professional/gynecology-and-obstetrics/vaginitis-cervicitis-and-pelvic-inflammatory-disease/pelvic-inflammatory-disease-pid Vaginal pH balance: Normal levels and natural remedies - Medical News Today, 8월 2, 2025에 액세스, https://www.medicalnewstoday.com/articles/322537 Vaginal pH Balance: Normal vs. Unbalanced, Symptoms, More - Healthline, 8월 2, 2025에 액세스, https://www.healthline.com/health/womens-health/vaginal-ph-balance Understanding Vaginal pH: What's Normal and When to See Your OB/GYN - Raleigh-OBGYN, 8월 2, 2025에 액세스, https://www.raleighob.com/understanding-vaginal-ph/ Vaginal microecological characteristics of women in different physiological and pathological period - Frontiers, 8월 2, 2025에 액세스, https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.959793/full Periods & vaginal microbiota: Science in progress… | Content for the lay public, 8월 2, 2025에 액세스, https://www.biocodexmicrobiotainstitute.com/en/periods-vaginal-microbiota-science-progress Role of Vaginal pH in STD Susceptibility | Hope Across The Globe, 8월 2, 2025에 액세스, https://hopeacrosstheglobe.org/the-role-of-vaginal-ph-in-std-susceptibility/ The immune system and the menstrual cycle - Clue app, 8월 2, 2025에 액세스, https://helloclue.com/articles/cycle-a-z/the-immune-system-and-the-menstrual-cycle Does intercourse during menses increase the risk for sexually transmitted disease? - PubMed, 8월 2, 2025에 액세스, https://pubmed.ncbi.nlm.nih.gov/20577749/ Pelvic Inflammatory Disease: Diagnosis, Management, and Prevention - AAFP, 8월 2, 2025에 액세스, https://www.aafp.org/pubs/afp/issues/2019/0915/p357.html Pelvic Inflammatory Disease - AAFP, 8월 2, 2025에 액세스, https://www.aafp.org/pubs/afp/issues/2012/0415/p791.html Symptoms of Pelvic Infection - MyHealth Alberta, 8월 2, 2025에 액세스, https://myhealth.alberta.ca/Health/pages/conditions.aspx?hwid=sig52761 Risk factors for pelvic inflammatory disease. A case control study, 8월 2, 2025에 액세스, https://pubmed.ncbi.nlm.nih.gov/8724516/ I had sex with my girlfriend while she was on her period, will I be affected with any diseases?, 8월 2, 2025에 액세스, https://youngwomenshealth.org/askus/sex_period_std/ On the causation of pelvic inflammatory disease - PubMed, 8월 2, 2025에 액세스, https://pubmed.ncbi.nlm.nih.gov/6372489/ Pelvic Inflammatory Disease: Current concepts in pathogenesis, diagnosis and treatment, 8월 2, 2025에 액세스, https://pmc.ncbi.nlm.nih.gov/articles/PMC3843151/ Coitus during menses. Its effect on endometriosis and pelvic ..., 8월 2, 2025에 액세스, https://pubmed.ncbi.nlm.nih.gov/2585390/ STDs That Affect Your Period | STDs & Menstruation | Everlywell, 8월 2, 2025에 액세스, https://www.everlywell.com/blog/sti-testing/stds-that-affect-your-period/ Sexually transmitted disease (STD) symptoms - Mayo Clinic, 8월 2, 2025에 액세스, https://www.mayoclinic.org/diseases-conditions/sexually-transmitted-diseases-stds/in-depth/std-symptoms/art-20047081 Endometriosis - Symptoms and causes - Mayo Clinic, 8월 2, 2025에 액세스, https://www.mayoclinic.org/diseases-conditions/endometriosis/symptoms-causes/syc-20354656 Endometriosis - World Health Organization (WHO), 8월 2, 2025에 액세스, https://www.who.int/news-room/fact-sheets/detail/endometriosis Endometriosis > Fact Sheets > Yale Medicine, 8월 2, 2025에 액세스, https://www.yalemedicine.org/conditions/endometriosis Coital Retrograde Menstruation as a Risk Factor for Pelvic Endometriosis - QScience.com, 8월 2, 2025에 액세스, https://www.qscience.com/content/journals/10.5339/qmj.2011.1.9?crawler=true&mimetype=application/pdf Could sexual activity during menses be a risk factor in endometriosis? - EndoNews.com, 8월 2, 2025에 액세스, https://www.endonews.com/could-sexual-activity-during-menses-be-a-risk-factor-in-endometriosis- Association between Sexual Activity during Menstruation and Endometriosis: A Case-Control Study - PMC, 8월 2, 2025에 액세스, https://pmc.ncbi.nlm.nih.gov/articles/PMC6642425/ Sexual activity during menstruation: Any impact on endometriosis development?, 8월 2, 2025에 액세스, https://www.endonews.com/sexual-activity-during-menstruation-any-impact-on-endometriosis-development Sexual Activity, Orgasm and Tampon Use Are Associated with a Decreased Risk for Endometriosis - ResearchGate, 8월 2, 2025에 액세스, https://www.researchgate.net/publication/11320843_Sexual_Activity_Orgasm_and_Tampon_Use_Are_Associated_with_a_Decreased_Risk_for_Endometriosis Can a Man Get an Infection From Period Blood? - Verywell Health, 8월 2, 2025에 액세스, https://www.verywellhealth.com/infection-from-period-blood-5409610 Sexually Transmitted Blood Borne Infections (STBBI) - Ottawa Public Health, 8월 2, 2025에 액세스, https://www.ottawapublichealth.ca/en/public-health-topics/sexually-transmitted-blood-borne-infections.aspx Can you get an STD from period blood? - Better2Know, 8월 2, 2025에 액세스, https://www.better2know.com/en/blog/can-you-get-an-std-from-period-blood Can You Get HIV (or Any STI) From Period Blood? - TheBody, 8월 2, 2025에 액세스, https://www.thebody.com/article/hiv-and-menstruation Menstrual health and HIV - Aidsmap, 8월 2, 2025에 액세스, https://www.aidsmap.com/about-hiv/menstrual-health-and-hiv Yeast infection in men: How can I tell if I have one? - Mayo Clinic, 8월 2, 2025에 액세스, https://www.mayoclinic.org/healthy-lifestyle/mens-health/expert-answers/male-yeast-infection/faq-20058464 Sexually Transmitted Infections: Symptoms, Diagnosis & Treatment - Urology Care Foundation, 8월 2, 2025에 액세스, https://www.urologyhealth.org/urology-a-z/s/sexually-transmitted-infections Cervicitis: Causes, Symptoms, Diagnosis & Treatment - Cleveland Clinic, 8월 2, 2025에 액세스, https://my.clevelandclinic.org/health/diseases/15360-cervicitis Is Sex During Your Period Safe? Benefits, Pregnancy Risk, and STIs - Healthgrades Health Library, 8월 2, 2025에 액세스, https://resources.healthgrades.com/right-care/womens-health/sex-during-period Pelvic Inflammatory Disease (PID) - STI Treatment Guidelines - CDC, 8월 2, 2025에 액세스, https://www.cdc.gov/std/treatment-guidelines/pid.htm