Serum C-reactive protein and Chlamydia trachomatis antibodies in preterm delivery.
OBJECTIVE
To assess the association between Chlamydia trachomatis antibodies, antibodies to C trachomatis heat shock proteins 60 and 10, and C-reactive protein (CRP) levels in maternal serum measured by highly sensitive CRP assay during the first trimester and spontaneous preterm delivery before 37 weeks of gestation.


METHODS
This was a nested case-control study of 104 spontaneous preterm singleton deliveries (cases) and 402 term singleton deliveries, as controls, of mothers belonging to the population-based Northern Finland 1966 Birth Cohort. Data on 2,309 first deliveries were available from the Finnish Medical Birth Register. Serum C trachomatis and C pneumoniae antibodies were measured by the microimmunofluorescence test and chlamydial heat shock proteins 60 and 10 antibodies by enzyme immunoassay using recombinant proteins as antigens, and highly sensitive CRP levels were quantified with highly sensitive immunoenzymometric assay.


RESULTS
Highly sensitive CRP levels were higher and C trachomatis immunoglobulin G levels (pools and individual serotypes) were more often present (thought not nominally significantly in all cases) in the women with preterm compared with term deliveries. Elevated immunoglobulin G levels of C trachomatis antibodies or elevated highly sensitive CRP levels alone, however, did not increase the estimated risk for preterm delivery, but when they were present simultaneously, the estimated risk for preterm delivery was 4-fold (odds ratio 4.3, 95% confidence interval 2.0-9.3). Among the women delivered at or before 34 weeks of gestation, the estimated risk was even more evident (odds ratio 5.6, 95% confidence interval 2.1-14.5). The preterm delivery rate was 26.5% for those with C trachomatis antibodies and 18.8% for those without C trachomatis antibodies.


CONCLUSIONS
The results of the present study suggest that chlamydial infection in the first trimester is associated with preterm delivery.


METHODS
II-2.
Karinen
Liisa
L
Department of Obstetrics and Gynecology, University Hospital of Oulu, Finland. Liisa.Karinen@oulu.fi
Pouta
Anneli
A
Bloigu
Aini
A
Koskela
Pentti
P
Paldanius
Mika
M
Leinonen
Maija
M
Saikku
Pekka
P
Jêrvelin
Marjo-Riitta
MR
Hartikainen
Anna-Liisa
AL
D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis*; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000032:analysis / Q000378:metabolism*; D016022:Case-Control Studies; D018834:Chaperonin 60 / Q000032:analysis / Q000378:metabolism; D002692:Chlamydia trachomatis / Q000276:immunology* / Q000302:isolation & purification; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008423:Maternal Age; D007752:Obstetric Labor, Premature / Q000209:etiology* / Q000401:mortality; D016017:Odds Ratio; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis*; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011336:Probability; D018570:Risk Assessment; D012680:Sensitivity and Specificity
D000907:Antibodies, Bacterial; D015415:Biomarkers; D018834:Chaperonin 60; D002097:C-Reactive Protein