Fig. 7: Cervical shortening is associated with activation of the adaptive and innate immune response, especially in the presence of Lactobacillus iners.

Cervicovaginal immune mediators were analysed in women between 12–16 weeks gestation prior to intervention (a–e). Thirteen women had a cervical length (CL) ≤ 25 mm and 96 women had a cervical length >25 mm. Median concentrations of IgM (a), C5 (b), C5a (c), IL-6 (d), and IL-10 (e) are presented, n = 109 women. Statistical analysis was performed using a one-sided Mann–Whitney test. The percentage of women with a short cervix (≤25 mm) or long cervix (>25 mm) with L. iners at 12–16 weeks is presented in f, and the proportion of L. iners sequences is presented in g, n = 111 women. Immune mediators were analysed and compared between women who had L. iners (CST III) who developed cervical shortening (CL ≤ 25 mm) and women who maintained a CL > 25 mm. Mediators of microbial recognition included MBL (h), IgM (i), IgG1 (j), IgG2 (k), IgG3 (l), IgG4 (m), C3b (n), C5 (o), C5a (p), IL-8 (q), IL-6 (r), IL-1β (s), IL-10 (t), n = 64 samples. Statistical analyses were performed using a one-sided Chi square to compare proportions of VMG 3 between women with a CL ≤ 25 mm and >25 mm (f), and a one-sided Mann–Whitney to compare differences between sequence percentages and immune mediators (g–t), (h–t). Data are presented as median values and interquartile ranges (25th and 75th percentiles). Source data are provided as a Source Data file.