This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diagnosis of Pregnancy, Subject name: Gynaecology & Obstetrics
Vaginal changes in normal pregnancy show: 
Select and explain. 
A. High pH, B. Increased lactobacilli, C. Increased anaerobic bacteria, D. Decrease in glycogen contents
B: Increased lactobacilli
Answer: B: Increased lactobacilli 
Explanation: The considerably increased volume of cervical secretions within the vagina during pregnancy consists of a somewhat thick, white discharge. The pH is acidic, varying from 3.5 to 6. This results from increased production of lactic acid from glycogen in the vaginal epithelium by the action of Lactobacillus acidophilus. The number of Lactobacilli also increase.