Elevated vaginal pH in the absence of current vaginal infection, still a challenging obstetrical problem

Abstract

Objective: To assess the association of vaginal pH ≥ 5 in the absence of vaginal infection with systemic inflammation and adverse pregnancy outcome.

Methods: Four-hundred sixty pregnant women completed the study, upon enrollment Vaginal pH was measured for all women, maternal and umbilical sera were obtained for determining C-reactive protein (CRP) and uric acid levels. Umbilical blood was tested for gas parameters, 1 and 5 min Apgar scores, the need for neonatal resuscitation and neonatal intensive care unit (NICU) admission were recorded.

Results: Elevated vaginal pH was significantly associated with preterm birth (odds ratio (OR), 2.23; 95% confidence interval (CI), 1.04-4.76), emergency cesarean section (OR 2.57; 95% CI 1.32-5), neonatal resuscitation in the delivery room (OR 2.85; 95% CI 1.1-7.38), elevated cord base deficit (OR 8.01; 95% CI 1.61-39.81), low cord bicarbonate (OR 4.16, 95% CI 1.33-12.92) and NICU admission (OR 2.02; 95% CI 1.12-3.66). Increased vaginal pH was also significantly associated with maternal leukocytosis, hyperuricemia and elevated CRP levels in maternal and umbilical sera.

Conclusions: Elevated vaginal pH in the absence of current vaginal infection still constitutes a risk for adverse pregnancy outcome which is mediated by systemic inflammatory response.