Lactobacilli Deficiency in Infertile Women Seeking IVF in Arash Hospital: An Imbalance in the Genital Microbiome

It is estimated that infertility affects approximately 9-30% of couples in their reproductive age and microorganisms may play an important role in such genital system dysfunction. The aim of this study was to investigate the presence of lactobacilli, Gardnerella, Enterobacteriaceae, and streptococci in the vagina, cervix and endometrium of women who referred for infertility and the healthy women who referred for oocyte donation.

The endometrial, cervical and vaginal swab specimens were collected three days after the end of menstruation and cultured to isolate lactobacilli. DNA form these specimens was extracted and subjected to quantitative real-time PCR to determine the frequency of the above bacteria. All uterine biopsy samples were tested for the presence of bacterial DNA by PCR method.

94% of uterine biopsy samples contained bacterial DNA. The frequency of lactobacilli identified by real-time quantitative PCR in these two groups was 40% (endometrial samples), 70% (cervical samples), and 80% (vaginal samples), which differed from lactobacilli isolated by the culture method. The number of lactobacilli from cervical endometrium of healthy donors was higher than in the diseased group. There was a significant difference in the mean of Gardnerella bacteria in the cervix and endometrium and Streptococcus in the cervix (p<0.05).

Considering the decrease of lactobacilli and the increase of other bacteria, it is suggested to consider the composition and number of bacteria in the genital tract of asymptomatic infertile women as one of the possible causes of infertility.