Association of Chlamydia trachomatis and Mycoplasma hominis with intrauterine growth retardation and preterm delivery. The John Hopkins Study of Cervicitis and Adverse Pregnancy Outcome.

The authors conducted a prospective study of risk factors for intrauterine growth retardation (birth weight less than a standard (race- and sex-adjusted) 10th percentile for gestational age) and preterm birth (birth prior to 37 weeks gestation) in a high-risk, inner-city, obstetric population, with special interest in pathogens colonizing the maternal genital tract. A total of 801 women within 22 to 30 weeks of gestation were enrolled and interviewed. Subjects were cultured for Gardnerella vaginalis, group B streptococcus, Trichomonas vaginalis, Neisseria gonorrhoeae, Bacteroides fragilis, Mycoplasma hominis, Ureaplasma urealyticum, Chlamydia trachomatis, and Candida albicans, and they were followed to delivery. Intrauterine growth retardation and preterm delivery occurred in 8% and 13% of these pregnancies, respectively. After adjustment for other important risk factors, colonization with C. trachomatis was significantly associated both with intrauterine growth retardation (odds ratio = 2.4, 90% confidence interval 1.32-4.18) and preterm delivery (odds ratio = 1.6, 90% confidence interval 1.01-2.50). Colonization with C. albicans was significantly associated with intrauterine growth retardation (odds ratio = 1.9, 90% confidence interval 1.20-3.14); colonization with M. hominis was significantly associated with preterm birth (odds ratio = 2.0, 90% confidence interval 1.42-2.93). These associations support the probable role of infection in preterm and intrauterine growth retardation births and suggest the need for carefully designed intervention studies.