The Male Reproductive System
The male reproductive system is both internal and external. Internally, the testicles located in the scrotal sac produce sperm and testosterone. Sperm production takes approximately 10-12 weeks to occur and once sperm mature, they leave the testes and enter the epididymis where they are stored and nourished for approximately 14 days. They then move into the vas deferens until ejaculation. At the time of ejaculation, they leave the vas deferens and combine with fluid from the seminal vesicles and prostate gland to create semen which is expelled from the penis.
During intercourse, normally millions of sperm are deposited into the vagina. As they make their way through the female reproductive tract (vagina / cervix / uterus / fallopian tubes) their numbers drop drastically until only a few hundred sperm get close to the egg; although several sperm try, only one sperm will, on occasion, successfully fertilize the egg within the fallopian tube. Sperm can survive in the female reproductive tract for 2 to 3 days and the time that the egg is within the fallopian tube ranges from 12 to 24 hours.
Just like in women, the main pituitary hormones that regulate the reproductive process are FSH (follicle stimulating hormone) which stimulates production of sperm in the testicles, and LH (luteinizing hormone) which stimulates the production of testosterone.
Factors Influencing Male Infertility
- Behavioral Factors: Nutrition, exercise, smoking, drug, and alcohol intake can influence overall health and fertility.
- Medications: Several medications, including those used to treat high blood pressure or ulcers, can influence a man’s sperm count and libido and should be discussed with the prescribing primary care physician. The use of testosterone injections or gels will cause severe effects on sperm production and should be discontinued when attempting to achieve pregnancy.
- Drugs: The use of cigarettes, marijuana, anabolic steroids, and cocaine may have profound effects on sperm counts. At times, in the case of steroids, this effect may be irreversible.
What Causes Male Factor Infertility?
Male factor infertility as the sole cause of infertility accounts for 40% of infertility cases. Causes of male infertility are somewhat limited. This diagnosis can be seen in men who are diagnosed with a varicocele, which is an enlarged vein within one or both of the testicles. However, in many cases, urologists may determine that it is of no clinical significance. Male infertility can also occur as a result of trauma or surgery to the testicles. In addition, scientific studies have also shown that in some cases of male infertility, there may be a significant genetic component which may be heritable. Men with an otherwise undiagnosed mutation in the cystic fibrosis gene may also suffer from congenital absence of a portion of the reproductive tract called the vas deferens. In some cases, known or unknown environmental exposures may contribute to decrease sperm counts or viability. Primary testicular failure can also be a cause of infertility, however, this is rare and diagnosed by checking blood hormone levels. Despite the above causes, a significant portion of male infertility remains unexplained.
How Is Male Factor Infertility Diagnosed?
Semen Analysis: this test is performed by one of our highly skilled andrologists who perform microscopic evaluation of the sperm and evaluate key parameters such as:
- Volume – The amount of semen produced in a single ejaculate
- Concentration – The number of sperm seen per milliliter of seminal fluid
- Motility – The percentage of sperm that are moving in the sample
- Progression – A measure of how well the moving sperm are moving
- Kruger Strict Morphology – This is the percentage of normally shaped sperm present; this impacts sperm’s ability to fertilize an egg on its own
- Presence of white blood cells and viscosity – Presence of white blood cells may indicate an infection or inflammatory process in the male reproductive tract. This usually requires referral to an urologist and possibly treatment with antibiotics for 30 days prior to repeat testing.
Since only highly trained andrologists can perform this test, we will ask that this test be performed within our Center. Crucial information obtained from the semen analysis for characteristics such as sperm count and shape helps us determine what technique to use to facilitate the sperm fertilizing the egg. These options include timed intercourse, intrauterine insemination, conventional IVF, or IVF with ICSI (intracytoplasmic sperm injection).
- Endocrine Blood Tests: For men who have abnormal semen analysis results, blood tests to measure hormones can uncover potential causes of infertility. The main hormones that usually are tested include FSH, LH, estrogen, prolactin, thyroid, and testosterone. These results along with the semen analysis and physical exam may aid the urologist and determining the cause of the abnormality.
- Infectious Screening: all males who seek care within our facility will undergo HIV, Hepatitis B, Hepatitis C, and Syphilis blood screening. Since these organisms may be passed through the semen, this is a requirement by the State of Arizona prior to using sperm for insemination or cryopreservation.
- Karyotype (Chromosome analysis): Usually recommended based on medical history or previous pregnancy attempts, this is a chromosome analysis which may identify potentially significant abnormalities which prevent fertilization and pregnancy. In addition, chromosome abnormalities may also be responsible for increased miscarriage rates. Subsequent treatment options may include Preimplantation Genetic Screening or Diagnosis with IVF or the use of donor sperm.
- Y Chromosome Deletion Testing: This test is ordered when sperm concentrations on semen analysis are below a threshold value. In some cases of very low sperm concentrations, structural abnormalities in a portion of the Y chromosome that controls development of sperm in the testicles lead to decreased natural pregnancy rate. Using thereproductive technique of ICSI along with IVF, fertilization can usually be achieved; however these abnormalities may be passed on to any male offspring.
- Sperm Chromatin Structure Assay (SCSA): This is a relatively new testing procedure which is implemented in cases of recurrent pregnancy loss and failed fertilization possibly related to male factor infertility. This test analyzes for defects in DNA fragmentation in the sperm. Studies have shown that significant abnormalities predict reduced probability for natural conception. Fortunately,Fertility Care’sprocedures like IVF with ICSI compensate for these decreased statistics. However, even with thesetechniques, the scientific data to date suggests a pregnancy rate reduced by 66% and a doubling of the spontaneous pregnancy loss rate. Therefore, this test is reserved for certain of our patients suffering from recurrent pregnancy loss or unexpected and otherwise unexplained repeated unsuccessful IVF cycles.
- Cystic Fibrosis Genetic Screening: has been associated with congenital absence of the vas deferens (a key element of the male reproductive tract).
- Urologist Consultation: Men who have severe abnormalities in their semen analysis will be referred to a urologist for a complete physical evaluation to rule out the presence of testicular masses or anatomic abnormalities. The urologist may also recommend hormonal testing and subsequent treatments to improve sperm parameters. In certain circumstances, the urologist may work with Advanced Fertility Care Physicians to perform surgical procedures to access sperm from the male reproductive tract for the use in more fertility treatment.
How Is Male Factor Infertlity Treated?
The good news for couples who have male factor infertility is that it is one of the most easily treatable conditions. In severe cases of male factor, treatment begins initially with a visit to a specially trained urologist who is used to assessing and treating male factor infertility. If anatomic issues are present, these may need to be addressed surgically by the urologist. In many cases, however, fertility treatments such as artificial insemination, also known as intrauterine insemination (IUI) may be all that is needed to overcome these minor issues. In slightly more severe cases of male factor, IVF with intracytoplasmic sperm injection (ICSI), in which the sperm are individually chosen and used to fertilize eggs harvested from the female is performed. Only in very specialized situations would moreurological procedures such as percutaneous epididymal sperm aspiration (PESA), testicular sperm aspiration (TESA), testicular sperm extraction (TESE), or microsurgical epididymal sperm aspiration (MESA) be required.
Regardless of the treatment needed, the outcome with the appropriate fertility treatment is very positive.