TABLE 1.

General properties of individual studies included in the meta-analysis: vaginal microbiome of five cohorts of term and preterm patients: Hyman et al. (2014), Romero et al. (2014b), DiGiulio et al. (2015), Callahan et al. (2017), and Stout et al. (2017).

	Callahan et al., 2017	DiGiulio et al., 2015	Hyman et al., 2014	Romero et al., 2014b	Stout et al., 2017
Number of participants	135	37	82	87	74
Number sampled while pregnant	135	37	82	87	74
Number delivering preterm	50	5	16	18	23
Overall preterm ratio	37%	12.5%	21%	17.33%	31.1%
Number sampled during trimester 1	42 (10 PTB)	21 (4 PTB)	37 (5 PTB)	6 (2 PTB)	14 (4 PTB)
Number sampled during trimester 2	135 (50 PTB)	31 (4 PTB)	50 (10 PTB)	76 (17 PTB)	55 (18 PTB)
Number sampled during trimester 3	123 (39 PTB)	36 (4 PTB)	46 (9 PTB)	60 (5 PTB)	59 (17 PTB)
Sampling time points	One per week	One per week	One per trimester	One every 4 weeks (<24 GW) One every 2 weeks (>24 GW)	One per trimester
Number of samples collected during trimester 1	116 (28 PTB)	58 (12 PTB)	27 (4 PTB)	4 (2 PTB)	15 (4 PTB)
Number of samples collected during trimester 2	987 (310 PTB)	303 (46 PTB)	49 (10 PTB)	178 (47 PTB)	56 (19 PTB)
Number of samples collected during trimester 3	909 (204 PTB)	270 (21 PTB)	28 (8 PTB)	141 (7 PTB)	60 (18 PTB)
Number of samples from white individuals	578 (65 PTB)	413 (45 PTB)	51 (11 PTB)	14 (4 PTB)	33 (9 PTB)
Number of samples from black individuals	1004 (356 PTB)	16 (0 PTB)	8 (2 PTB)	281 (52 PTB)	88 (30 PTB)
Number of samples from Asian individuals	110 (15 PTB)	45 (0 PTB)	17 (5 PTB)	5 (0 PTB)	0 (0 PTB)
Number of samples from other race individuals	267 (95 PTB)	157 (34 PTB)	28 (4 PTB)	28 (4 PTB)	10 (2 PTB)