The impact of bacterial and uterine factors on subfertility

Abstract

This thesis aimed to assess the impact of bacterial vaginosis (BV) and caesarean section scars on subfertility. In chapter 2 the relationship between (asymptomatic) bacterial vaginosis and pregnancy rates during intra uterine insemination or in vitro fertilization treatment (IVF) is investigated. The incidence of BV was 26%. This chapter reveals a higher incidence of miscarriages and a tendency to lower live birth rates among participants testing positive for BV. Chapter 3 showed that a simple pH-measurement could accurately predict if subfertile participants are BV positive. During fertility treatments, the vaginal microbiome of participants changes, as shown in chapter 4. Chapter 5 shows no difference in the time to pregnancy based on BV-status in participants at initial fertility assessment. However, participants with a lower chance to conceive tended to have a longer time to pregnancy if they were BV positive. Chapter 6 shows that participants with a previous caesarean delivery had significant lower live birth rates during IVF treatment compared to a previous vaginal delivery. The review of chapter 7 showed an adverse effect on live birth rates in persons with a caesarean scar niche. A potential relationship between abnormal microbiome (or BV) and a niche could not be accurately assessed.