Spontaneous abortion‐an infectious aetiology?

Abstract

The role of Chlamydia trachomatis, genital mycoplasmas, Campylobacter spp. and other aerobic and anaerobic bacteria in the aetiology of spontaneous abortion was investigated prospectively in 24 1 pregnant women at a community hospital. Sixteen women who had threatened abortions were a little younger, of lower social class and had had more previous spontaneous abortions than the 76 women who aborted or the 149 women whose pregnancies were not complicated in the early stages by haemorrhage. The demographic characteristics of the latter two groups of women were similar. C. trachomatis was isolated from the cervix of only one woman and she had no genital-tract bleeding at any stage in her pregnancy. Mycoplasma hominis was isolated most often from the women who had threatened abortions but otherwise the prevalence of the other various micro-organisms was similar in women who had spontaneous abortions, threatened abortions, and in those who had pregnancies uncomplicated by vaginal bleeding. It was clear, therefore, that C. trachomatis played no role in the aetiology of spontaneous abortion in the population studied and there was no suggestion that any of the other micro-organisms were involved either.

Adverse pregnancy and birth outcomes associated withMycoplasma hominis, Ureaplasma urealyticumandUreaplasma parvum: a systematic review and meta-analysis

“…Of the 57 studies, we identified 42 reporting on M. hominis (proportion detected <1%–70%), 31 reporting on U. urealyticum (proportion detected 0%–91%) and 12 reporting on U. parvum (2%–100%) and median sample size 250, interquartile range (IQR) 145–613, range 3732 to 910533 (table 1, online supplemental file, table S1). There were 26 cohort studies (online supplemental file, table 2.1),1 6 8 12 15 33–53 25 case–control studies (online supplemental file, table 2.2)7 9–11 32 54–73 and six cross-sectional studies (online supplemental file, table 2.3). 74–79 Most studies were from high-income settings (39/57) (online supplemental file, table S3.1-S3.3); ethnicity was reported in 24 studies, and maternal smoking in 12 (online supplemental file, table S4.1-S4.3).…”

“…In 10 studies with data about PND,8 35 40 45 51 54 55 76 77 meta-analysis of unadjusted ORs found an association with M. hominis (3696 women, summary OR 2.70, 95% CI 1.31 to 4.54; I 2 30.4%; prediction interval 0.52 to 13.94) (online supplemental file, figure S3.3). In 10 studies with data about SA,6 7 11 35 36 39 40 51 55 63 there was no association with M. hominis in meta-analysis of unadjusted ORs (4531 women, summary OR 0.93, 95% CI 0.44 to 1.49; I 2 50.2%; prediction interval 0.12 to 7.14) (online supplemental file, figure S3.4). No results of multivariable analyses were reported for PND or SA.…”

Mycoplasmas in pregnancy

“…What also remains unanswered is whether ureaplasmas alone without BV are associated with SPTL and PTB. On the one hand, some investigators have been unable to find a relationship between the presence of ureaplasmas and fetal loss, 70,71 yet in other studies, the isolation of these organisms was much more common among PTBs, miscarriages and stillbirths than from healthy infants born at term or following therapeutic abortion, and was not entirely the result of superficial contamination as, in some instances, organisms were isolated from deep fetal tissues (lungs, brain, heart and viscera). 3 In the case of preterm infants, taking one study as an example, ureaplasmas were isolated from 62 (86%) women who delivered after SPTL and from 12 (46%) women who delivered electively for fetomaternal indications (P < 0.01).…”