Hum Reprod Update. 1999 Jul-Aug;5(4):373-85.

Hypothesis on the role of sub-clinical bacteria of the endometrium (bacteria endometrialis) in gynaecological and obstetric enigmas.
Viniker DA.

Department of Obstetrics and Gynaecology, Whipps Cross Hospital, London, UK.

Unexplained infertility, recurrent abortion, dysfunctional uterine bleeding, pelvic pain, premenstrual syndrome, premature labour, placental insufficiency and pre-eclampsia are examples of common obstetric and gynaecological problems that frequently defy adequate explanation. Bacterial vaginosis, a non-inflammatory condition, is associated with premature labour, but antibiotics administered topically provide less effective prophylaxis than those administered orally. This would indicate that bacterial vaginosis might be a marker for significant genital tract bacteria, but some pathology is dependent on micro-organisms ascending out of reach of topical antibiotics. The author was led to consider the hypothesis that micro-organisms, possibly those associated with bacterial vaginosis, surreptitiously inhabit the uterine cavity (bacteria endometrialis) where they are culprits of some common gynaecological and obstetric enigmas. The objective of this review is to provide an initial theoretical examination of this hypothesis. Bacteria in the endometrium have been associated with infertility. Antiphospholipids have been linked to recurrent miscarriage and pre-eclampsia and with infections including Mycoplasma. Pre-eclampsia might be explained by an exaggerated host response to intrauterine micro-organisms or bacterial toxins. The hypothesis that one common factor, bacteria endometrialis, could provide a plausible explanation for a variety of obstetric and gynaecological mysteries is particularly intriguing. There is sufficient evidence to justify further investigation.