[Usefulness of vaginal pH measurements in the identification of potential preterm births].

Ascending infections of the female genital tract as a cause of preterm birth have become major importance regarding the prevention of preterm birth. Measurements of the vaginal pH value are able to verify a alkalinisation of the vagina caused by a atypical vaginal flora. In a prospective study we measured the vaginal pH value using indicator paper and evaluated the results of a vaginal and cervical smear of 162 single pregnancies from 26 to 30 weeks of gestation. In contrast to normal pregnancies there is a relation between a pathological pH value > 4.5 and consequent preterm birth in pregnancies with preterm labour but also in pregnancies with other risk factors without symptoms of preterm labour.