Table 2. Characteristics and birth outcomes of pregnant women with active syphilis treated with amoxicillin or ampicillin, by syphilis stage, Japan, 2010–2018*.
| Category | Early syphilis, n = 31 | Late syphilis, n = 49 | p value† |
|---|---|---|---|
| Age, y | 26 (21–28) | 25 (22–27) | 0.63 |
| Japanese | 29/31 (94) | 46/49 (94) | 1.00 |
| HIV co-infection |
0/31 |
1/49 (2) |
1.00 |
| Diagnosis and treatment | |||
| Rapid plasma reagin titer at diagnosis | 44 (27–64) | 58 (29–83) | 0.64 |
| Amoxicillin | 28/31 (90) | 38/49 (78) | 0.23 |
| Ampicillin | 3/31 (10) | 11/49 (22) | |
| Antimicrobial drug dosage, mg/d | 1,500 (1,500–1,500) | 1,500 (1,500–1,500) | 0.56 |
| Received 1,500 mg/d | 26/31 (84) | 35/49 (71) | 0.22 |
| Total duration of treatment, d‡ | 30 (28–64) | 78 (51–104) | 0.004 |
| Duration of treatment at delivery, d‡ | 30 (26–56) | 70 (29-98) | 0.016 |
| Gestational age at diagnosis, wk‡ | 15.1 (11.1–27.5) | 13.3 (12–25.6) | 0.70 |
| Gestational age at treatment, wk‡ | 17.3 (13.3–28.7) | 14.7 (13–26) | 0.62 |
| Gestational age at delivery, wk‡ | 39.4 (38.1–40.6) | 38.9 (37.7–40.5) | 0.10 |
| Time from treatment to delivery, wk‡ |
15.7 (0.4–25.9) |
23 (16.7–27.2) |
0.73 |
| Birth outcomes | |||
| Live birth with congenital syphilis diagnosis | 0/26 | 13/45 (29) | 0.009 |
| Stillbirth | 0/26 | 1/45 (2) | |
| Miscarriage | 0/26 | 1/45 (2) | |
| Birth weight, g‡ | 2,902 (2,652–3,184) | 2,942 (2,555–3,155) | 0.88 |
| Low birth weight, <2,500 g‡ | 3/26 (12) | 8/45 (18) | 0.52 |
| Very low birth weight, <1,500 g‡ | 0/26 | 3/45 (7) | 0.29 |
*Values are no./total (%) or median (interquartile range). †Used the Student t-test for continuous variables and either the χ2 test or Fisher exact test for categorical variables. ‡Denominators varied because of missing data. Anywhere from 1 to 11 cases might be missing.