Extended Data Fig. 7. Mode of delivery and the detection of bacterial signals.

a, b) The association of vaginal lactobacilli with the mode of delivery, as determined by the analysis of 466 samples by 16S amplicon sequencing which were successfully sequenced twice using Mpbio (a) and Qiagen (b) DNA isolation. Comparisons of the Mpbio and Qiagen DNA isolations highlight that the same patterns are observed in the associations with mode of delivery. Comparisons also show that the Qiagen DNA isolation was more sensitive, resulting in twice as many signals above the 1% threshold. Figures c-h were generated using all 498 placental samples using the highest value of either DNA isolation method for each bacterial group per sample. c, d) S. agalactiae was not associated with the mode of delivery irrespective of whether a 0.1% threshold was used (the 16S detection limit, relevant for detecting traces of contamination during delivery) or whether a 1% threshold was used (the minimum percentage considered to be potentially ecologically relevant). e, f) The Ureaplasma genus was associated with the mode of delivery, comparable to Figure 2c which describes the combination of all vaginosis associated bacteria. g, h) F. nucleatum was not associated with the mode of delivery, irrespective of threshold. Comparisons between modes of delivery were performed by Mann-Whitney U tests. * P < 0.05, ** P < 0.01, *** P < 0.001.