Male infertility can be assessed again clinically
by evaluation of the history and physical exam.
On history, one should always ask the patient about potential
causes of infertility that they may have experienced.
These for example would include trauma to
the testicles or any prior condition that
may have affected their
ability to generate sperm.
Have they had a developmental delay in the history or do they
have any family history of patients with genetic disorders?
Illness that required medications that could
potentially be toxic to spermogenesis.
Have they had any chronic illnesses?
Infections, prior surgery, drugs,
environmental exposure such as toxins in the
workplace, sexual history and prior fertility history
On physical exam, one is looking for
any evidence of androgen deficiency
and one also wants to do a
very detailed testicular exam
particularly looking for decrease in size of the
testicles or a decrease in the density of the testicles.
This can sometimes be done with
comparison to an orchiometer
Semen analysis would follow next.
Collect 2-3 days after sexual abstinence.
Abnormal semen analysis should always be repeated
in at least 2 weeks to confirm the diagnosis.
Abnormal results should generally be
referred to a reproductive endocrinologist.
Here's an algorithm to remind you of
the normal male reproductive axis.
Pulses of GnRH elicit pulses
of luteinizing hormone and FSH
FSH acts on the Sertoli cells
which assist sperm maturation
and produce inhibin B which is the major
negative regulator of basal FSH production.
The Leydig cells produce testosterone which feeds back
negatively to inhibit GnRH and luteinizing hormone release
Some testosterone is irreversibly converted
to dihydrotestosterone or estradiol
which are both more potent than testosterone
in suppressing GnRH and lutenizing hormone.