Relationships between female infertility and female genital infections and pelvic inflammatory disease: a population-based nested controlled study

OBJECTIVES: Our purpose was to examine the associations of female genital infections and certain comorbidities with infertility. METHODS: The Taiwan National Health Research Database was searched for women with a new diagnosis of infertility between 2000 and 2013. Women without a diagnosis of infertility served as a control group and were matched with the infertility cases by age (±3 years) and index year. They were divided into two groups: ≤40 years old and >40 years old. Univariate and multivariate conditional logistic regression models were employed to identify the risk factors associated with infertility. RESULTS: A total of 18,276 women with a new diagnosis of infertility and 73,104 matched controls (mean cohort age, 31±6.2 years) were included. According to the adjusted multivariate analysis, pelvic inflammatory disease involving the ovary, fallopian tube, pelvic cellular tissue, peritoneum (odds ratio (OR)=4.823), and uterus (OR=3.050) and cervical, vaginal, and vulvar inflammation (OR=7.788) were associated with an increased risk of infertility in women aged ≤40 years. In women aged >40 years, pelvic inflammatory disease of the ovary, fallopian tube, pelvic cellular tissue, and peritoneum (OR=6.028) and cervical, vaginal, and vulvar inflammation (OR=6.648) were associated with infertility. Obesity, lipid metabolism disorders, dysthyroidism, abortion (spontaneous or induced), bacterial vaginosis, endometritis, and tubo-ovarian abscess were associated with an increased risk of infertility according to the univariate analysis but not the multivariate analysis. CONCLUSIONS: Female genital tract infections, but not the comorbidities studied here, are associated with an increased risk of infertility.