Microbial flora of the lower genital tract during pregnancy: relationship to morbidity.

Nineteen genera and groups of micro-organisms were isolated from the lower genital tract of 280 women at their first antenatal visit. Chlamydia, viruses, and T-strain mycoplasmas were not sought, and only routine methods of anaerobic culture were used. Growth was recorded as scanty, moderate or heavy. The population studied was grouped according to age, parity, gestational stage at booking, presence and degree of severity of lower genital tract morbidity, past history of vulvovaginitis, and suspicion of lower genital tract morbidity as evidenced by a request for a report on the microbiological findings. The frequency of isolation of the various microbes in health and in disease is given. The grading of Gram-stained smears bore no relation to the isolation rates of lactobacilli, but there was a significant increase (p less than 0-001) in the isolation rates of each of the following: Mycoplasma hominis, Bacteroides spp., Trichomonas vaginalis, Gram-variable cocco-bacilli, and anaerobic streptococci in those patients with smears in which lactobacilli were adjudged to be absent. The isolation of faecal streptococci was increased (p less than 0-001) in women aged more than 34 years. Escherichia coli (p less than 0-05) and anaerobic and microaerophilic streptococci (p less than 0-02) were isolated more frequently from those booking after the 25th week of pregnancy. The incidence of M. hominis (p less than 0-02) and of anaerobic streptococci (p less than 0-05) increased between the first and third trimesters. No significance positive correlations were established between the isolation rates of the various microbes and objective assessment of lower genital tract morbidity or the demonstration of pus cells, but lactobacilli were isolated less frequently (p less than 0-01) from those with morbidity. The isolation of Candida albicans (p less than 0-02), T. vaginalis (p less than 0-05), and M. hominis (p less than 0.05) was increased in patients in whom vulvovaginitis was suspected, and that of T. vaginalis (p less than 0-05) was increased in those with a past history of vulvovaginitis. The study indicates that, other than the pathogens T. vaginalis and C. albicans, only M. Hominis could be suspected, on statistical grounds, of being associated with disease of the lower genital tract during early pregnancy.