Objective To determine whether routine testing for serum Chlamydia trachoma
tis antibodies, considered in combination with a woman's clinical features,
may avoid the need for diagnostic laparoscopy in routine investigation for
infertility.
Design Retrospective case notes analysis.
Setting Secondary level care infertility clinic.
Population Eighty women who had undergone both laparoscopy and serum Chlamy
dia trachomatis antibody testing.
Methods Ascertainment of any history of suspected pelvic inflammatory disea
se, pelvic pain, cervical intraepithelial neoplasia, pelvic surgery or appe
ndicectomy; any abnormality an clinical pelvic examination; the findings at
laparoscopy; the result of serum Chlamydia trachomatis antibody testing by
enzyme-linked immunosorbent assay (ELISA) screening with microimmunofluore
scence (MIF) confirmatory diagnostic testing. The usefulness of clinical fe
atures, the serum Chlamydia trachomatis antibody test and these two variabl
es combined in the detection of tubal disease: and pelvic pathology of rele
vance to infertility were measured statistically.
Main outcome measures Specificity, sensitivity, positive predictive value,
negative predictive value and likelihood ratio for each of the tests.
Results The combination of any positive clinical feature with a positive te
st for serum Chlamydia trachomatis antibodies detects tubal disease with se
nsitivity 92%, specificity 70%, positive predictive value 72%, negative pre
dictive value 91% and likelihood ratio 3.1; it detects bilateral, tubal obs
truction with sensitivity 84%, specificity 51%, positive predictive value 3
5%, negative predictive value 91% and likelihood ratio 1.7; it detects pelv
ic pathology relevant: to infertility with sensitivity 76%, specificity 71%
, positive predictive value 80%, negative predictive value 65% and likeliho
od ratio 2.6. The negative predictive value for pelvic pathology from the u
se of clinical features in addition to the chlamydia antibody test is not s
ignificantly higher than that from the chlamydia antibody test alone (53%).
Conclusions A policy of selective laparoscopy in routine investigation for
infertility, based on the result of the test for serum Chlamydia trachomati
s antibodies and a woman's clinical features, is not supported.