Is There Any Relationship between Maternal Vitamin D Levels and Asymptomatic Bacteriuria? A Preliminary Study

Hypothesis: Vitamin D has been considered to play important roles in maintaining pregnancy. Also, this vitamin is considered to regulate immune response and thus may be important for pregnant women also to maintain no-infection of which preterm delivery is especially important. Since vitamin D regulates maternal anti-infection function and since Asymptomatic bacteriuria (ASB) causes various adverse outcomes in pregnancy, we hypothesized that maternal serum vitamin D level may be related with the presence/absence of ASB. The present study was an effort to determine this. The study included 215 pregnant women, attended the Ondokuz Mayis University Hospital antenatal care polyclinic, Samsun, Turkey, in the summer for initial visits between 6- and 14-weeks’ gestation. Women with symptoms suggestive of urinary tract infection, a history of antibiotic use within the previous two weeks, ongoing antibiotic therapy or urinary system instrumentation, a diagnosis of vitamin D insufficiency or deficiency, and those taking vitamin D supplements were excluded. Demographic data features of the sampled women were analyzed retrospectively. 10 ml maternal peripheral venous blood samples were collected and the concentrations of 25(OH)D3 in the serum were analyzed. Mid-stream morning urine samples were obtained and analyzed at the microbiology laboratory according to established procedures. ASB was reported if bacteria were present at specified quantitative counts (≥105 CFU/ml) in the urine without any sign or symptom. Participants were divided into two groups: ASB (-)—participants without ASB (n = 200) and: ASB (+)—participants with ASB (n = 15). There was no statistically significant relationship between the two groups in terms of demographic features. There was no statistically significant relationship between the distribution of maternal 25(OH)D3 levels in the two groups (p > 0.05). The comparison of maternal median 25(OH)D3 levels between the two groups showed no statistically significant difference (p = 0.576). No statistically significant correlation was found between 25(OH)D3 levels and age, gravida, parity, body weight, or gestation week (p > 0.05). Although there was no significant relationship between maternal vitamin D levels and ASB in this research, further studies in larger groups will increasingly highlight and clarify this topic.