Table 3. Association between class of antibiotic and number and timing of antibiotic prescriptions in pregnancy with cerebral palsy and/or epilepsy in childhood.
| Number (%) of women | Number of children with cerebral palsy and/or epilepsy | Follow-up in child-years-at-risk (CYAR) | Incidence rate of cerebral palsy and/or epilepsy per 100,000 CYAR (95% confidence interval) | Unadjusted hazard ratio (95% confidence interval) | Adjusted†‡ hazard ratio (95% confidence interval) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| TYPE†—Group of antibiotic prescribed (n = 41,276 women with single prescriptions for most commonly prescribed antibiotics in pregnancy) | Penicillins | 27,577 | (66.8%) | 156 | 108,630 | 143.6 | (122.8, 168.0) | [Ref] | [Ref] | ||
| Cephalosporins, carbapenems, and other beta-lactams | 7,740 | (18.8%) | 40 | 28,327 | 141.2 | (103.6, 192.5) | 0.96 | (0.68, 1.36) | 0.99 | (0.69, 1.41) | |
| Sulphonamides and trimethoprim | 1,375 | (3.3%) | 7 | 5,169 | 135.4 | (64.6, 284.1) | 0.93 | (0.45, 1.95) | 0.89 | (0.43, 1.85) | |
| Nitrofurantoin | 802 | (1.0%) | 6 | 2,900 | 206.9 | (93.0, 460.5) | 1.42 | (0.65, 3.13) | 1.31 | (0.58, 2.92) | |
| Metronidazole and tinidazole | 1,033 | (2.5%) | 9 | 3,987 | 225.7 | (117.4, 433.8) | 1.56 | (0.82, 2.99) | 1.5 | (0.78, 2.88) | |
| Macrolides | 2,749 | (6.7%) | 28 | 11,012 | 254.3 | (175.6, 368.3) | 1.77** | (1.18, 2.68) | 1.78** | (1.18, 2.69) | |
| NUMBER‡—No. antibiotic prescriptions (n = 195,909 women with any number of prescriptions) | 0 | 131,286 | (67.0%) | 739 | 514,030 | 143.8 | (133.8, 154.5) | [Ref] | [Ref] | ||
| 1 | 42,065 | (21.5%) | 252 | 163,203 | 154.4 | (136.5, 174.7) | 1.07 | (0.92, 1.25) | 0.98 | (0.84, 1.14) | |
| 2 | 14,166 | (7.2%) | 96 | 54,385 | 176.5 | (144.5, 215.6) | 1.22 | (1.00, 1.50) | 1.04 | (0.84, 1.29) | |
| 3+ | 8,392 | (4.3%) | 83 | 31,792 | 261.1 | (210.5, 323.7) | 1.80*** | (1.41, 2.31) | 1.40* | (1.07, 1.83) | |
| TIMING†—by lunar month of antibiotic prescription (n = 42,065 women with single prescriptions) | M1 | 4,182 | (9.9%) | 24 | 16,452 | 145.9 | (97.8, 217.6) | [Ref] | [Ref] | ||
| M2 | 3,689 | (8.8%) | 18 | 13,888 | 129.6 | (81.7, 205.7) | 0.88 | (0.47, 1.65) | 0.89 | (0.47, 1.67) | |
| M3 | 3,655 | (8.7%) | 22 | 13,591 | 161.9 | (106.6, 245.8) | 1.09 | (0.63, 1.90) | 1.12 | (0.64, 1.94) | |
| M4 | 4,387 | (10.4%) | 23 | 16,746 | 137.3 | (91.3, 206.7) | 0.93 | (0.51, 1.73) | 0.95 | (0.51, 1.76) | |
| M5 | 4,356 | (10.4%) | 19 | 16,819 | 113 | (72.1, 177.1) | 0.77 | (0.43, 1.38) | 0.78 | (0.43, 1.42) | |
| M6 | 4,227 | (10.0%) | 31 | 16,345 | 189.7 | (133.4, 269.7) | 1.3 | (0.76, 2.22) | 1.3 | (0.75, 2.23) | |
| M7 | 4,246 | (10.1%) | 31 | 16,757 | 185 | (130.1, 263.1) | 1.27 | (0.76, 2.13) | 1.29 | (0.77, 2.16) | |
| M8 | 4,222 | (10.0%) | 35 | 16,580 | 211.1 | (151.7, 294.0) | 1.45 | (0.89, 2.34) | 1.45 | (0.89, 2.36) | |
| M9 | 4,434 | (10.5%) | 26 | 17,515 | 148.4 | (101.1, 218.0) | 1.02 | (0.58, 1.79) | 1.03 | (0.58, 1.82) | |
| M10 | 4,667 | (11.1%) | 23 | 18,511 | 124.3 | (82.6, 187.0) | 0.85 | (0.48, 1.53) | 0.87 | (0.48, 1.56) | |
* p<0.05
** p<0.01
*** p<0.001
† Analyses on TYPE and TIMING of prescription—Cox regression models adjusted for year of delivery, Townsend quintile, and potentially neurologically-damaging infection recorded during pregnancy.
‡ Analysis on NUMBER of prescriptions—Cox regression model adjusted for maternal age, Townsend quintile, year of delivery, smoking/tobacco use, alcohol problems, obesity, illicit drug use, treatment of chronic medical conditions and potentially neurologically-damaging infection during pregnancy.