Common Causes Male Overview Male Overview
For a man to be fertile, his sperm cells must be healthy and be transported to their destination – the egg. Most cases of male infertility are due to sperm abnormalities, yet any of the following can play a role:
- Low sperm count
- Abnormally shaped sperm cells
- Sperm that are immobile or have impaired movement
- Impaired delivery of sperm
Sperm basics
Fertilization depends on sperm that are properly shaped (morphology) and able to move (motility) rapidly and accurately toward the egg. Impaired motility and morphology can result in sperm not reaching the egg.
Sperm count or concentration refers to the number of sperm cells per milliliter of semen. Men with 10 million or fewer sperm per milliliter are considered subfertile. Approximately 20 million or higher is considered average; 40 million sperm or higher per milliliter indicates increased fertility.
Low Sperm Count (Oligospermia or Azoospermia)
In terms of the male’s role, conception really is a game of numbers. Fundamentally, the more sperm cells a man produces, the greater the likelihood that one of the billions will hit their target – the egg cell.
Spermatogenesis
Spermatogenesis is simply the process in which spermatogonia, the building blocks of sperm, develop into mature sperm. Just as the female body has a hormonal relay system to produce egg cells ready for fertilization, the male body has its counterpart in the endocrine (hormonal) system’s series of events to create sperm cells:
Genetic Causes of Male Infertility
Genetic anomalies can be the cause of severe sperm abnormalities in men. For most of these men to become fathers, they will need , intracytoplasmic sperm injection (ICSI) , a laboratory process of injecting sperm directly into an egg with a tiny needle as part of in vitro fertilization (IVF ).
Diethylstilbestrol (DES) Sons
Diethylstilbestrol (DES) is a medication once prescribed in the United States to prevent miscarriage or premature delivery. Doctors stopped prescribing DES after the discovery of medical problems in the children of women who had taken it while pregnant – known as DES sons and DES daughters [link].
Pregnancy with Advanced Paternal Age
It has become common knowledge that women's fertility declines with age. In contrast, the assumption traditionally has been that men have no similar "biological clock," that they are virtually as fertile at age 60 or 70 as at age 30. Increasing studies, however, now strongly indicate that assumption to be incorrect. It appears that men, too, may need to start thinking about biological parenthood before they turn 40.
