Comparisons according to penicillin allergy status at initial prenatal visit and whether allergy testing was performed
| Characteristic | Penicillin allergy reported at prenatal visit | P value* | ||
| No (n=1030) | Yes and either a documented valid allergy or tested (n=125)† | Yes and not tested (n=111)† | ||
| Gravidity during pregnancy, median (IQR) | 2 (1, 3) | 2 (1, 3) | 2 (2, 4) | 0.014 |
| Parity during pregnancy, median (IQR) | 1 (0, 2) | 1 (0, 2) | 1 (0, 2) | 0.17 |
| Age (years), mean (SD) | 30.2 (5.1) | 30.4 (4.2) | 30.7 (4.9) | 0.67 |
| Prepregnancy BMI (kg/m2) | N=763 | N=114 | N=81 | 0.46 |
| Median (IQR) | 25.1 (21.8, 30.1) | 24.4 (22.2, 28.9) | 24.7 (22.8, 32.1) | |
| Alcohol use | 0.006 | |||
| Yes | 295 (28.6%) | 56 (44.8%) | 37 (33.3%) | |
| No | 693 (67.3%) | 66 (52.8%) | 71 (64.0%) | |
| Not documented | 42 (4.1%) | 3 (2.4%) | 3 (2.7%) | |
| Tobacco use | 0.64 | |||
| Yes | 89 (8.6%) | 9 (7.2%) | 11 (9.9%) | |
| No | 929 (90.2%) | 116 (92.8%) | 98 (88.3%) | |
| Not documented | 12 (1.2%) | 0 (0.0%) | 2 (1.8%) | |
| Illicit drug use | 0.82 | |||
| Yes | 45 (4.4%) | 5 (4.0%) | 6 (5.4%) | |
| No | 943 (91.6%) | 117 (93.6%) | 102 (91.9%) | |
| Not documented | 42 (4.1%) | 3 (2.4%) | 3 (2.7%) | |
| Marital status | 0.09 | |||
| Married or life partnership | 791 (76.8%) | 106 (84.8%) | 82 (73.9%) | |
| Single, divorced, separated or widowed | 239 (23.2%) | 19 (15.2%) | 29 (26.1%) | |
| Education level | 0.002 | |||
| High school degree or less education | 163 (15.8%) | 6 (4.8%) | 16 (14.4%) | |
| Associate degree or some college | 223 (21.7%) | 28 (22.4%) | 26 (23.4%) | |
| Bachelor’s degree or more | 570 (55.3%) | 88 (70.4%) | 66 (59.5%) | |
| Not documented | 74 (7.2%) | 3 (2.4%) | 3 (2.7%) | |
| Group B Streptococcus testing | 0.002 | |||
| Positive | 178 (17.3%) | 21 (16.8%) | 20 (18.0%) | |
| Negative | 626 (60.8%) | 95 (76.0%) | 64 (57.7%) | |
| Not documented or not done | 226 (21.9%) | 9 (7.2%) | 27 (24.3%) | |
| Pregnancy outcomes, among those who delivered at an affiliated institution | N=806 | N=119 | N=90 | |
| Delivery route | 0.026 | |||
| Caesarean delivery | 230 (28.5%) | 37 (31.1%) | 38 (42.2%) | |
| Vaginal | 576 (71.5%) | 82 (68.9%) | 52 (57.8%) | |
| Gestational age (weeks), median (IQR) | 39.1 (38.4, 40) | 39.3 (38.4, 40.0) | 39.0 (37.6, 39.4) | 0.019 |
| Birth weight (g), median (IQR) | 3395 (3050, 3742) | 3480 (3170, 3720) | 3375 (2900, 3680) | 0.18 |
IQR=25th and 75th percentiles.
*Comparisons between the groups were evaluated using an F-test from a one-way analysis of variance model for age, the non-parametric Kruskal-Wallis test for all other continuous or count variables and the χ2 test for all other variables. A p value <0.05 indicates that at least two of the three subgroups are significantly different from each other. For patient characteristics with an overall p value <0.05, additional pairwise comparisons were performed between the subgroups and the significant results of these comparisons are reported in the ‘Results’ section.
†Among the 236 patients with a penicillin allergy reported at a prenatal visit, 125 had either a documented valid penicillin allergy (n=24) or were tested during the current pregnancy (n=101). The remaining 111 were not tested because either testing was not offered (n=62) or the patient refused (n=49).
BMI, body mass index.