Utilidad de la determinación del pH vaginal para el diagnóstico de las vulvovaginitis y su relación con la patología obstétrica

Objective

To assess the usefulness of vaginal pH determination in the first prenatal visit in the diagnosis of vulvovaginitis and its association with obstetric abnormalities.

Material and methods

We determined vaginal pH in the first prenatal visit in 200 low-risk pregnancies. In 103 women, vaginal secretions were cultured, independently of their symptoms. In the remaining 97 women, culture was performed only if symptoms were present and/or pH was >4.5. Treatment was prescribed in symptomatic women only. The pregnancies were followed up to evaluate obstetric abnormalities and data on deliveries.

Results

The mean pH in the study sample was 4.41 (4.04–4.78). We found a statistically significant association (P<.000) between an increase in vaginal pH over 4.5 and isolation through culture of Gardnerella vaginalis (G. vaginalis), with an OR of 35.15 (4.67–730.39). Most cultures were normal. In order of frequency, the identified microorganisms were Candida albicans (C. albicans) (17.5%), G. vaginalis (7.8%) and Streptococcus agalactiae (7.8%). More than 85% of the carriers were asymptomatic. Obstetric pathology in our sample consisted of preterm labor (2%), premature rupture of membranes (2%), preterm delivery (4.5%) and miscarriage (6%).

Conclusions

Vaginal pH determination might be an effective screening test for the diagnosis of bacterial vaginosis. The most prevalent microorganism in our sample was C. albicans and most carriers were asymptomatic. We found no relationship between obstetric pathology and the microorganisms isolated in cultures of vaginal secretions.