Page and Houlding developed a nomogram for predicting a male patient's fertility based on spermatozoal number, motility and head normalcy.
Nomogram components:
(1) column 1: spermatozoal number
(2) column 2: intermediate state determined by drawing a line from column 1 to 3
(3) column 3: percent motile spermatozoa 2 hours after ejaculation
(4) column 4: fertility index, determined by a line drawn from column 2 to column 5
(5) column 5: normal head forms in percent
|
Component |
Values |
Data Range |
Column Display |
|---|---|---|---|
|
spermatozoal number |
millions per mL |
10 (and under) to 80 (and over) |
|
|
intermediate state |
unitless |
0 to 19 |
linear |
|
motile spermatozoa |
percent |
10 (and under) to 55 (and over) |
nonlinear intervals |
|
fertility index |
unitless |
0.1 to 80 |
log10 |
|
normal head forms |
percent |
75 (and under) to 88 (and over) |
possibly log10 |
value for column 2 from column 1 and 3 =
= (-0.003086 * ((motile sperm in percent)^2)) + (0.404984 * (motile sperm in percent)) + (-0.001146 * ((sperm number in millions)^2)) + (0.2374 * (sperm number in millions)) – 5.686822
log10(value for fertility index) =
= (0.102068 * (value from column 2)) + B
|
Percent Head Normalcy |
value for B |
|---|---|
|
75 and under |
-1 |
|
76-80 |
(0.13435 * (percent normal)) – 10.94573 |
|
81 – 88 (and over) |
(0.0251 * (percent normal)) – 2.201767 |
fertility index =
= 10^(log10 value)
Interpretation:
• minimum fertility index: 0.1
• maximum fertility index: 80
|
Fertility Index |
Fertility |
|---|---|
|
0.1 to 5 |
probably infertile |
|
5 to 50 |
possibly fertile |
|
50 to 80 |
fertile |
NOTE: The value for the fertility index I get by this method differs a little from that given by the nomogram, but it looks close enough for clinical use. The calculation of the column 2 value is close to that given by the nomogram. The problem appears to be in the calculation of the log10 value with the deviation amplified by the exponential.
Purpose: To evaluate a man's fertility based on sperm analysis using the nomogram of Page and Houlding.
Specialty: Urology, Clinical Laboratory
Objective: other testing, criteria for diagnosis, differential diagnosis and mimics, red flags
ICD-10: N46,
