The Capillary Tube Test for Evaluating the Sperm and Cervical Mucus Interaction

 

Procedure:

(1) The apparatus is described on pages 110-111 of the WHO Manual (1999). This involves capillary tubes filled with cervical mucus having one end sealed and the other placed in a cup-shaped reservoir into which the patient's sperm is placed.

(2) The sperm should not be more than 1 hour post-ejaculation.

(3) The tubes are placed on a gradated slide to allow distance measurements along the capillary tube. This is then placed in a Petri dish holding a damp sponge to prevent drying of the samples.

(4) Initial readings are done at 2 hours.

(5) At 24 hours a reading of sperm movement is made.

 

Parameters measured:

(1) migration distance

(2) penetration density (number of sperm per low power microscopic field)

(3) migration reduction (change in rank order numbers)

(4) duration of progressive movements of sperm in the cervical mucus

 

migration distance at 2 hours =

= distance in cm that the sperm have migrated from the reservoir

 

penetration density at 2 hours =

= mean number of sperm per low power field in 5 microscopic fields

 

where:

• The examination is done at 1 cm and 4.5 cm along the capillary tube.

• The examination is done at low power with 10x objective and 10x ocular lenses.

• The larger of the two values is used for classification of the test results.

Penetration Density	Rank Order Number
0	1
1 - 5	2
6 - 10	3
11 - 20	4
21 - 50	5
51 - 100	6
> 100	7

 

migration reduction from 1 to 4.5 cm at 2 hours =

= (rank order number at 1 cm) - (rank order number at 4.5 cm)

 

duration of progressive movements =

= number of hours forward motility is demonstrated by the spermatozoa in the cervical mucus

 

where:

• The evaluation for motility is determined at 2 and 24 hours.

 

Interpretation

 

Test Findings	Classification
migration distance <=1 cm, AND penetration density at 1 cm = 0	negative
migration distance < 3 cm, OR penetration density < 10, OR migration reduction > 3, OR duration of movements in mucus <= 2 hours	poor
migration distance = 4.5 cm, AND penetration density > 50, AND migration reduction < 3, AND duration of movements in mucus > 24 hours	good
all other combinations	fair