Volume 162 l'\umber 3
CLINICAL SECTION Clinical Opinion The validity of the postcoital test Carolyn S. Griffith, MD, and David A. Grimes, MD
Los Angeles, California Opinion is divided on the clinical usefulness of the postcoital (Sims-Huhner) test in diagnosing infertility. To evaluate the validity of this test, we reviewed the world's literature In English and calculated four indexes of validity for each study with sufficient information. The sensitivity of the test ranged from 0.09 to 0.71, specificity from 0.62 to 1.00, predictive value of abnormal from 0.56 to 1.00, and predictive value of normal from 0.25 to 0.75. In addition to the problem of poor validity, the test suffers from a lack of standard methodology, lack of a uniform definition of normal, and unknown reproducibility. The postcoital test lacks validity as a test for infertility. (AM J OSSTET GVNECOL 1990;162:615-20.)
Key words: Postcoital test, infertility, semen, cervical mucus What is unacceptable is to persist in demonstrably ineffective practices either because we fail to collect systematic information about the effects of our actions or because we establish and respond to inappropriate incentives. 1 Since it was first described by the father of American gynecology in 1866,2 the postcoital test (also known as the Sims-Huhner test) has been widely used in infertility investigations. Despite more than a century of experience with this test, its clinical utility is still debated in the literature. Some investigators' suggest that it is so informative that it eliminates the need for semen analysis, whereas others' contend that it merely confirms the occurrence of vaginal intercourse. Because of this disagreement and the widespread use of this test, we conducted a review of the literature and analyzed the validity of the postcoital test for predicting infertility.
Material and methods We conducted a Medline search of publications in English related to the postcoital test. We also consulted textbook chapters, review articles, and infertility experts in our search for relevant literature. For inclusion in our study, investigations had to include sufficient description of material and methods to allow for anal-
From the Department of ObstetriCs and Gynecology, UniverSIty of Southern California School of Medicine. Reprznt requests: Davul A. Grimes, MD, Women's HospItal, Room LJ013, 1240 N. MISSIOn Road, Los Angeles, CA 90033. 6/1/16661
ysis, the results of the postcoital test had to be categorized as either positive or negative (i.e., normal or abnormal), and the numbers of pregnancies had to be reported. For each study"lU we calculated four indexes of test validity: sensitivity, specificity, and the predictive value of abnormal and normal results. The sensitivity of the postcoital test as a diagnostic test describes its ability to detect infertility. The specificity describes its ability to identify fertility. The predictive value of abnormal is the likelihood that a couple with an abnormal postcoital test result is actually infertile. The predictive value of normal is the likelihood that a couple with a normal test result is fertile. We also examined the correlation between sperm density and pregnancy rates in those studies providing this information and plotted receiver-operating characteristic curves" for the two largest studies.' 10 The postcoital test involves two assessments: (1) an evaluation of the characteristics of the mucus: amount, viscosity, spinnbarkeit, and cellularity and (2) a measure of the number and motility of sperm found. Abundant, clear, highly elastic mucus of the periovulatory period is optimal for sperm penetration. Such mucus may be available for only 1 to 2 days of the cycle.'" Not all the reports we analyzed correlated the quality of the mucus with the pregnancy rate. Some treated quality of the mucus and sperm density as separate diagnostic entities. 5 • 10 Others 8 made the presence of good mucus a prerequisite for a valid test. Still others 7 9 studied populations undergoing ovulation induction and thus were able to control ovulation timing and mucus characteristics. Since the value of good mucus is widely accepted 615
616 Griffith and Grimes
March 1990
Am J Obstet Gynecol
Table I. Summary of patient evaluations in studies of the postcoital test Diagnostic tests Author and reference no.
Patient population
Jette and Glass*5
Infertility patients
Giner et al. 6
Fertile with recent spontaneous abortions Ovulation-induction patients Infertility patients
Franken and Slabber7 Hull et al.·t Skaf and Kemmann Collins et al. 10
9
*
Ovulation-induction patients Infertility patients
I
Hysterosalpingogram
I
Seman analysIS
Interval from coitus to test (hr)
Excluswns
Laparoscopy
Artifical insemination, ovulation induction NS
NS
NS
NS
CLINICAL SECTION Clinical Opinion The validity of the postcoital test Carolyn S. Griffith, MD, and David A. Grimes, MD
Los Angeles, California Opinion is divided on the clinical usefulness of the postcoital (Sims-Huhner) test in diagnosing infertility. To evaluate the validity of this test, we reviewed the world's literature In English and calculated four indexes of validity for each study with sufficient information. The sensitivity of the test ranged from 0.09 to 0.71, specificity from 0.62 to 1.00, predictive value of abnormal from 0.56 to 1.00, and predictive value of normal from 0.25 to 0.75. In addition to the problem of poor validity, the test suffers from a lack of standard methodology, lack of a uniform definition of normal, and unknown reproducibility. The postcoital test lacks validity as a test for infertility. (AM J OSSTET GVNECOL 1990;162:615-20.)
Key words: Postcoital test, infertility, semen, cervical mucus What is unacceptable is to persist in demonstrably ineffective practices either because we fail to collect systematic information about the effects of our actions or because we establish and respond to inappropriate incentives. 1 Since it was first described by the father of American gynecology in 1866,2 the postcoital test (also known as the Sims-Huhner test) has been widely used in infertility investigations. Despite more than a century of experience with this test, its clinical utility is still debated in the literature. Some investigators' suggest that it is so informative that it eliminates the need for semen analysis, whereas others' contend that it merely confirms the occurrence of vaginal intercourse. Because of this disagreement and the widespread use of this test, we conducted a review of the literature and analyzed the validity of the postcoital test for predicting infertility.
Material and methods We conducted a Medline search of publications in English related to the postcoital test. We also consulted textbook chapters, review articles, and infertility experts in our search for relevant literature. For inclusion in our study, investigations had to include sufficient description of material and methods to allow for anal-
From the Department of ObstetriCs and Gynecology, UniverSIty of Southern California School of Medicine. Reprznt requests: Davul A. Grimes, MD, Women's HospItal, Room LJ013, 1240 N. MISSIOn Road, Los Angeles, CA 90033. 6/1/16661
ysis, the results of the postcoital test had to be categorized as either positive or negative (i.e., normal or abnormal), and the numbers of pregnancies had to be reported. For each study"lU we calculated four indexes of test validity: sensitivity, specificity, and the predictive value of abnormal and normal results. The sensitivity of the postcoital test as a diagnostic test describes its ability to detect infertility. The specificity describes its ability to identify fertility. The predictive value of abnormal is the likelihood that a couple with an abnormal postcoital test result is actually infertile. The predictive value of normal is the likelihood that a couple with a normal test result is fertile. We also examined the correlation between sperm density and pregnancy rates in those studies providing this information and plotted receiver-operating characteristic curves" for the two largest studies.' 10 The postcoital test involves two assessments: (1) an evaluation of the characteristics of the mucus: amount, viscosity, spinnbarkeit, and cellularity and (2) a measure of the number and motility of sperm found. Abundant, clear, highly elastic mucus of the periovulatory period is optimal for sperm penetration. Such mucus may be available for only 1 to 2 days of the cycle.'" Not all the reports we analyzed correlated the quality of the mucus with the pregnancy rate. Some treated quality of the mucus and sperm density as separate diagnostic entities. 5 • 10 Others 8 made the presence of good mucus a prerequisite for a valid test. Still others 7 9 studied populations undergoing ovulation induction and thus were able to control ovulation timing and mucus characteristics. Since the value of good mucus is widely accepted 615
616 Griffith and Grimes
March 1990
Am J Obstet Gynecol
Table I. Summary of patient evaluations in studies of the postcoital test Diagnostic tests Author and reference no.
Patient population
Jette and Glass*5
Infertility patients
Giner et al. 6
Fertile with recent spontaneous abortions Ovulation-induction patients Infertility patients
Franken and Slabber7 Hull et al.·t Skaf and Kemmann Collins et al. 10
9
*
Ovulation-induction patients Infertility patients
I
Hysterosalpingogram
I
Seman analysIS
Interval from coitus to test (hr)
Excluswns
Laparoscopy
Artifical insemination, ovulation induction NS
NS
NS
NS
