Table 1. Baseline Participant Characteristics.
| Characteristics | Pessary (n = 280) | Usual care (n = 264) |
|---|---|---|
| Maternal age, mean (SD), y | 29.9 (6.0) | 29.1 (5.9) |
| Race and ethnicity, No. (%)a | ||
| American Indian or Alaska Native | 1 (0.4) | 0 |
| Asian | 12 (4.3) | 16 (6.1) |
| Non-Hispanic Black | 132 (47.1) | 127 (48.1) |
| Hispanic | 62 (22.1) | 56 (21.2) |
| Native Hawaiian or Pacific Islander | 0 | 1 (0.4) |
| Non-Hispanic White | 61 (21.8) | 53 (20.1) |
| More than 1 race | 2 (1.0) | 2 (1.0) |
| Not reported or unknown | 10 (3.6) | 9 (3.4) |
| Body mass index at first clinic visit, median (IQR)b | 28.8 (24.3-34.2) (n = 276) | 28.6 (23.2-33.4) (n = 263) |
| <30 | 153 (55.4) | 162 (61.6) |
| 30.0-34.9 | 61 (22.1) | 49 (18.6) |
| 35.0-39.9 | 29 (10.5) | 30 (11.4) |
| ≥40.0 | 33 (12.0) | 22 (8.4) |
| Cigarette use during pregnancy, No. (%) | 30 (10.7) | 21 (8.0) |
| Married or living with partner, No. (%) | 167 (59.6) | 168 (63.6) |
| Employed full- or part-time, No. (%) | 191 (68.2) | 172 (65.2) |
| More than 12 y of education, No./total (%) | 176/280 (62.9) | 155/263 (58.9) |
| Insurance, No. (%) | ||
| Private | 145 (51.8) | 137 (51.9) |
| Government | 127 (45.4) | 121 (45.8) |
| Self-pay | 8 (2.9) | 6 (2.3) |
| Prior cervical surgery, No. (%)c | 33 (11.8) | 31 (11.7) |
| Previous pregnancy regardless of outcome, No. (%) | 103 (36.8) | 87 (33.0) |
| Total prior term deliveries, median (IQR) | 0 (0-1) | 0 (0-1) |
| Type of pregnancy, No. (%) | ||
| Spontaneous | 257 (91.8) | 245 (92.8) |
| In vitro fertilization | 18 (6.4) | 15 (5.7) |
| Ovulation induction/artificial insemination | 5 (1.8) | 4 (1.5) |
| Vaginal infection prior to enrollment, No. (%)d | 57 (20.4) | 55 (20.8) |
| Cervical length at screening, median (IQR), mm | 13.3 (9.1-17.2) | 13.7 (8.3-17.5) |
| <10 mm, No. (%) | 80 (28.6) | 82 (31.1) |
| Amniotic cavity debris on screening ultrasound, No./total (%) | 50/276 (18.1) | 44 (16.7) |
| Gestation at enrollment, median (IQR), wk | 21.7 (20.6-22.9) | 21.9 (20.7-23.2) |
| Time from screening to randomization, median (IQR), d | 0 (0-3) | 0 (0-3) |
| Current or planned progesterone use, No. (%) | 277 (98.9) | 261 (98.9) |
| Nugent score, No./total (%)e | ||
| 0-3 (normal flora) | 168/251 (66.9) | 161/234 (68.8) |
| 4-6 (intermediate) | 39/251 (15.5) | 34/234 (14.5) |
| 7-10 (bacterial vaginosis) | 44/251 (17.5) | 39/234 (16.7) |
a
Race and ethnicity are based on participant self-report.
b
Calculated as weight in kilograms divided by height in meters squared.
c
Any cervical surgery, including cervical cone, or loop electrosurgical excision procedure.
d
Includes chlamydia, gonorrhea, syphilis, trichomonas, bacterial vaginosis, genital herpes, HIV, hepatitis B, hepatitis C, hepatitis D, pyelonephritis, cystitis, or candidiasis diagnosed during the current pregnancy.
e
The Nugent score is a summary evaluation from the Gram stain of vaginal swabs. It ranges from 0 to 10, with scores of 7 or higher indicating bacterial vaginosis.