The role of mycoplasmas, ureaplasmas and chlamydiae in the genital tract of women presenting in spontaneous early preterm labour.

The genital carriage of Ureaplasma urealyticum, Mycoplasma hominis and Chlamydia trachomatis was assessed in 72 women admitted to hospital in spontaneous preterm labour and in 26 women requiring preterm delivery for other reasons who formed a control group. Women in preterm labour significantly more often carried ureaplasmas, had large numbers of M. hominis and subsequently developed chorioamnionitis than women in the control group. M. hominis, in particular, occurred more frequently and in large numbers in women who had chorioamnionitis associated with ruptured membranes. Genital carriage of the various micro-organisms appeared not to be associated with fetal growth retardation, although subsequent isolation of ureaplasmas from infants was common. It is suggested that mid-second-trimester vaginal specimens should be cultured on a research basis to establish whether these various micro-organisms identify women at risk of labouring preterm.