不妊治療中の夫婦へ：周囲の気遣いと伝えにくさへの対処法
男性不妊治療と禁欲期間の関係について
男性不妊治療において、禁欲期間の長さが受精率や妊娠率に影響を与えることが研究で明らかにされています。本記事では、男性不妊治療と禁欲期間の関係について詳しく解説し、その適切な期間や最新の研究成果を紹介します。
短い禁欲期間が生殖成績に良い影響を与える
最近の研究によれば、短い射精禁欲期間が妊娠率や生まれる赤ちゃんの数を向上させ、さらに精子のDNA損傷の可能性を減らすことが示唆されています[2 。また、短い禁欲期間と長い禁欲期間のカップル間で流産率に有意差は見られなかったという報告もあります[3 ]。これらの結果から、人工受精治療を受ける患者に対して短い禁欲期間が推奨されることがわかります。
禁欲期間と精子の質
禁欲期間が精子の質に与える影響についても研究が行われています。ある研究では、禁欲期間が短いほど精子の運動性や形態が良好であることが示されました[8 。このことから、禁欲期間を短くすることが精子の健康にプラスの影響を与えると考えられます。
A禁欲期間 --> B精子の質
B --> C受精率・妊娠率
どのくらいの禁欲期間が適切か？
適切な禁欲期間については、個人差があるため一概には言えません。しかし、研究によれば、2日から7日の禁欲期間が推奨されることが多いです[8 。しかし、最適な禁欲期間は個々の状況や治療法によって異なるため、医師と相談して決定することが重要です。
禁欲期間の長さが生殖能力に与える影響
禁欲期間が長すぎると、精子の質が低下し、受精率や妊娠率に悪影響を与える可能性があります。特に、精子の運動性や形態が低下することで、妊娠の確率が減少することが考えられます。一方で、禁欲期間が短すぎる場合、射精回数が増えるため、精子の数が減少する可能性があります。このため、適切な禁欲期間を見つけることが男性の生殖能力向上に重要です。
まとめ
男性不妊治療において、禁欲期間の適切な長さが重要であることがわかります。短い禁欲期間が精子の質や受精率、妊娠率に良い影響を与えるとの研究結果がある一方で、適切な期間は個人差があります。そのため、医師と相談しながら、自分に最適な禁欲期間を見つけることが大切です。
参考資料
1 () "Lifestyle Factors and Relationships Between Infertility and General Health. 5. Clinicians should counsel infertile men or men with abnormal semen parameters of the health risks associated with abnormal sperm production. (Moderate Recommendation; Evidence Level: Grade B) 6."
URL: https://www.auanet.org/guidelines-and-quality/guidelines/male-infertility
2 () "Overall, the review findings suggest that shorter ejaculation abstinence periods improved the rates of pregnancy and live births, while also reducing the likelihood of DNA fragmentation in ..."
URL: https://www.news-medical.net/news/20230320/Shorter-ejaculation-abstinence-times-linked-to-better-reproductive-outcomes-during-fertility-treatments.aspx
3 () "No significant difference in miscarriage rates between the short and long SAP couples was found (p = .88). The meta-analysis indicates that a shorter abstinence period could result in higher implantation and pregnancy rates for patients undertaking ART treatments."
URL: https://journals.sagepub.com/doi/full/10.1177/1557988320933758
4 () "Diagnosing male infertility problems usually involves: General physical examination and medical history. This includes examining your genitals and asking questions about any inherited conditions, chronic health problems, illnesses, injuries or surgeries that could affect fertility."
URL: https://www.mayoclinic.org/diseases-conditions/male-infertility/diagnosis-treatment/drc-20374780
5 () "In Karimpur's study in 2011, varicocele was responsible for 42.7% of cases of infertility in males (19). The higher prevalence of varicocele in the infertile men population is the most important evidence supporting the theory of the relationship between varicocele and male infertility (29)."
URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8458922/
6 () "The semen parameters of the men in couples trying to achieve a pregnancy might have changed due to the increased age at marriage. In this study, as expected, men with secondary infertility were older than men with primary infertility, consistent with other reports (Walsh et al., 2009). However, there were no differences in patient age between ..."
URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7517893/
7 () "Male reproduction is a complex process, and numerous medical conditions have the potential to alter spermatogenesis. In addition, male factor infertility may be a biomarker for future health. In the present review, we discuss the current literature regarding the association between systemic diseases …"
URL: https://pubmed.ncbi.nlm.nih.gov/32089256/
8 () "Tom Merton / Getty Images. If you want to have a baby, you need to have sex around the time of ovulation.But having frequent sex throughout the month also can boost fertility. That said, research also has shown that short periods of abstinence could have the potential to benefit sperm health—whether you are trying to conceive naturally or will be providing a sperm sample for insemination."
URL: https://www.verywellfamily.com/tips-to-increase-fertility-for-men-1959906
9 () "Infertility is defined as not being able to become pregnant after having regular intercourse (sex) without birth control after one year (or after six months if a woman is 35 or older). Infertility is common. Out of 100 couples in the United States, about 12 to 13 of them have trouble becoming pregnant. About one-third of infertility cases are ..."
URL: https://opa.hhs.gov/reproductive-health/understanding-fertility-basics
10 () "Obesity-Induced OS in Male Infertility. Obesity ensues when there is an energy imbalance between the energy consumed and energy expended, therein leading to excessive accumulation of fat ().Obesity is a multifactorial disorder influenced by genetic or environmental factors, and the incidence has tripled since 1975 as reported by the WHO ().In 2016, more than 1.9 billion adults of ≥18 years ..."
URL: https://www.frontiersin.org/articles/10.3389/frph.2022.822257/full
11 () "Male infertility is any health issue in a man that lowers the chances of his female partner getting pregnant. About 13 out of 100 couples can't get pregnant with unprotected sex. There are many causes for infertility in men and women. In over a third of infertility cases, the problem is with the man. This is most often due to problems with his ..."
URL: https://www.urologyhealth.org/urology-a-z/m/male-infertility
12 () "Abstinence and outercourse have lots of benefits. Both abstinence and outercourse are simple, free, and work really well to prevent pregnancy. In fact, abstinence is the only 100% effective way to avoid pregnancy. And outercourse really lowers your risk a lot. There are other benefits of abstinence. People choose abstinence to: wait until they ..."
URL: https://www.plannedparenthood.org/learn/birth-control/abstinence-and-outercourse/what-are-benefits-and-disadvantages-abstinence-and-outercourse
13 () "Infertility is typically defined as the inability to conceive after at least one year of regular, unprotected sex. This affects 15-20% of couples. 1 A male factor is estimated to be present in about 50% of cases, with sole responsibility in 30% of cases and a co-contributing female factor in 20% of factors. 2 Male infertility is associated with significant psychosocial and marital stress. 3"
URL: https://www.racgp.org.au/afp/2017/september/male-infertility/
14 () "Prevention. Male infertility describes a reproductive issue that results in a male being unable to impregnate their fertile partner. Studies indicate that approximately 15% of American heterosexual couples will encounter fertility issues when trying to conceive. Male infertility is a contributing factor to as many as half of all these cases and ..."
URL: https://www.verywellfamily.com/what-is-male-infertility-5212728
15 () "Infertility is medically defined as occurring when a woman is unable to get pregnant despite having unprotected sex for a year or longer. Because barriers fertility can exist in both men and women ..."
URL: https://www.psychologytoday.com/us/basics/infertility
16 () "Discover some signs of infertility in both men and women, as well as the risk factors, medical conditions, and drugs that may contribute to it. Also learn about diet tips, natural treatments ..."
URL: https://www.healthline.com/health/infertility
17 () "Medication. Medical therapies can be very effective for men with certain causes of infertility, such as hormonal abnormalities. For men with low testosterone, a number of medications, such as clomiphene citrate, human chorionic gonadotropin (HCG) and anastrozole, can help to boost the body's natural production of testosterone."
URL: https://www.nm.org/conditions-and-care-areas/urology/male-infertility
18 () "A lab analyzes your semen specimen. In some cases, urine may be tested for the presence of sperm. Hormone testing. You may have a blood test to determine your level of testosterone and other male hormones. Genetic testing. Genetic testing may be done to determine whether there's a genetic defect causing infertility."
URL: https://www.mayoclinic.org/diseases-conditions/infertility/diagnosis-treatment/drc-20354322
