Table 1.
Characteristics of all participants and by number of bacterial reads (≥ 100 and < 100).
| All participants (n = 141) | ≥ 100 reads (n = 92) | < 100 readsa (n = 49) | P ≥ 100 vs. < 100 readsb | |
|---|---|---|---|---|
| Median female age in years (IQR) | 35.7 (31.9–39.4) | 34.9 (31.2–39.4) | 36.5 (33.9–39.8) | 0.055 |
| Median female BMI in kg/m2 (IQR) c | 23.8 (21.6–26.4) | 23.5 (21.8–25.6) | 24.1 (21.4–27.9) | 0.214 |
| Median duration of infertility in months (IQR) | 30.0 (22.5–43.0) | 29.5 (23.0–43.0) | 31.0 (20.0–43.5) | 0.952 |
| Female smokers, n (%) d | 18 (12.8) | 8 (8.7) | 10 (20.4) | 0.061 |
| Type of infertility of female, n (%) e | 0.157 | |||
| Primary | 73 (51.8) | 52 (56.5) | 21 (42.9) | |
| Secondary | 68 (48.2) | 40 (43.5) | 28 (57.1) | |
| Cause of infertility, n (%) | 0.929 | |||
| Male factor | 69 (48.9) | 46 (50.0) | 23 (46.9) | |
| Unexplained | 60 (42.6) | 38 (41.3) | 22 (44.9) | |
| Otherf | 12 (8.5) | 8 (12.7) | 4 (8.2) | |
| Median # previous embryo transfers per participant (IQR) | 2.0 (1.0–3.0) | 2.0 (1.0–3.0) | 2.0 (1.0–3.0) | 0.854 |
| Pregnancy outcome during follow-up, n (%) | 0.593 | |||
| Live birthg | 61 (43.3) | 38 (41.3) | 23 (46.9) | |
| No live birth | 80 (56.7) | 54 (58.7) | 26 (53.1) | |
| No pregnancy | 70 (87.5) | 46 (85.2) | 24 (92.3) | |
| Pregnancy loss | 10 (12.5) | 8 (14.8) | 2 (7.7) | |
| Median number of reads per sample (IQR) | 442 (45–6067) | 2167 (532–11,839) | 13 (2–45) |
BMI body mass index, IQR interquartile range.
aSeven samples had 0 reads. The clinical characteristics of this group did not differ from the other 42 women who had between 1 and 99 reads, with the exception of smoking.
bAll continuous variables were compared using the Wilcoxon rank sum test, whereas all categorical variables were compared using the Fisher’s exact test.
cData was missing for one participant in the ≥ 100 reads group.
dData was missing for one participant in the < 100 reads group.
ePrimary: female has never conceived before. Secondary: female has conceived before.
fOther causes of infertility are tubal factor (≥ 100 reads: n = 1, < 100 reads: n = 4), ovulatory disorder (≥ 100 reads: n = 3), endometriosis (≥ 100 reads: n = 1) and mixed causes (≥ 100 reads: n = 3).
gOne woman conceived spontaneously, and all other women conceived via IVF/ICSI. The sample of the woman who conceived spontaneously had < 100 bacterial reads and was therefore not included in the analyses.