Table 1.
Baseline characteristics of matched pregnancy cohorts on propensity scores
| Characteristics | Macrolides v penicillin | Macrolides v recent use of macrolides | Macrolides v no antibiotics used | |||||
|---|---|---|---|---|---|---|---|---|
| Macrolides (n=13 017) |
Penicillin (n=13 017) | Macrolides (n=11 908) |
Recent use (n=11 908) | Macrolides (n=13 019) |
No antibiotics used (n=52 075) | |||
| GA at the start of drug use (median (IQR)) | 28 (13-54) | 27 (12-52) | 27 (12-52) | 28 (13-54) | ||||
| Age at pregnancy onset | ||||||||
| ≤19 | 584 (4.5) | 453 (3.5) | 496 (4.2) | 479 (4.0) | 586 (4.5) | 2428 (4.7) | ||
| 20-24 | 2321 (17.8) | 2267 (17.4) | 2112 (17.7) | 2107 (17.7) | 2321 (17.8) | 9513 (18.3) | ||
| 25-29 | 3909 (30.0) | 4051 (31.1) | 3625 (30.4) | 3696 (31.0) | 3909 (30.0) | 15576 (29.9) | ||
| 30-34 | 3969 (30.5) | 4038 (31.0) | 3646 (30.6) | 3629 (30.5) | 3969 (30.5) | 15864 (30.5) | ||
| ≥35 | 2234 (17.2) | 2208 (17.0) | 2029 (17.0) | 1997 (16.8) | 2234 (17.2) | 8694 (16.7) | ||
| Married or living with partner | 10129 (77.8) | 10282 (79.0) | 9269 (77.8) | 9356 (78.6) | 10129 (77.8) | 40548 (77.9) | ||
| Place of birth | ||||||||
| Denmark | 11475 (88.2) | 11514 (88.5) | 10593 (89.0) | 10727 (90.1) | 11476 (88.2) | 46278 (88.9) | ||
| Europe | 563 (4.3) | 527 (4.1) | 491 (4.1) | 432 (3.6) | 563 (4.3) | 2070 (4.0) | ||
| Outside of Europe | 979 (7.5) | 976 (7.5) | 824 (6.9) | 749 (6.3) | 980 (7.5) | 3727 (7.2) | ||
| Region of residence | ||||||||
| Capital Region of Denmark | 4241 (32.6) | 4312 (33.1) | 3822 (32.1) | 3934 (33.0) | 4241 (32.6) | 16994 (32.6) | ||
| Region Zealand | 2075 (15.9) | 2040 (15.7) | 1917 (16.1) | 1899 (16.0) | 2075 (15.9) | 8345 (16.0) | ||
| Region of Southern Denmark | 2870 (22.1) | 2948 (22.7) | 2645 (22.2) | 2634 (22.1) | 2871 (22.1) | 11492 (22.1) | ||
| Central Denmark Region | 2588 (19.9) | 2537 (19.5) | 2380 (20.0) | 2342 (19.7) | 2589 (19.9) | 10448 (20.1) | ||
| North Denmark Region | 1243 (9.6) | 1180 (9.1) | 1144 (9.6) | 1099 (9.2) | 1243 (9.6) | 4796 (9.2) | ||
| Gross household income* | ||||||||
| 1 | 4280 (32.9) | 4095 (31.5) | 3407 (28.6) | 3307 (27.8) | 4636 (35.6) | 18519 (35.6) | ||
| 2 | 3184 (24.5) | 3204 (24.6) | 3048 (25.6) | 2923 (24.6) | 3292 (25.3) | 13205 (25.4) | ||
| 3 | 2777 (21.3) | 2857 (22.0) | 2819 (23.7) | 2924 (24.6) | 2691 (20.7) | 10793 (20.7) | ||
| 4 | 2776 (21.3) | 2861 (22.0) | 2634 (22.1) | 2754 (23.1) | 2400 (18.4) | 9558 (18.4) | ||
| Education level (years) | ||||||||
| <12 | 4550 (35.0) | 4409 (33.9) | 4174 (35.1) | 4062 (34.1) | 4552 (35.0) | 18508 (35.5) | ||
| 12-13 | 1913 (14.7) | 1927 (14.8) | 1752 (14.7) | 1737 (14.6) | 1913 (14.7) | 7470 (14.3) | ||
| 14-15 | 3181 (24.4) | 3259 (25.0) | 2954 (24.8) | 2973 (25.0) | 3181 (24.4) | 12754 (24.5) | ||
| >15 | 3373 (25.9) | 3422 (26.3) | 3028 (25.4) | 3136 (26.3) | 3373 (25.9) | 13343 (25.6) | ||
| Year of start of pregnancy | ||||||||
| 1997-2000 | 3798 (29.2) | 3880 (29.8) | 3468 (29.1) | 3584 (30.1) | 3799 (29.2) | 15336 (29.5) | ||
| 2001-2004 | 3211 (24.7) | 3263 (25.1) | 2923 (24.6) | 2845 (23.9) | 3212 (24.7) | 12749 (24.5) | ||
| 2005-2008 | 2459 (18.9) | 2438 (18.7) | 2260 (19.0) | 2327 (19.5) | 2459 (18.9) | 9894 (19.0) | ||
| 2009-2012 | 2222 (17.1) | 2160 (16.6) | 2040 (17.1) | 1983 (16.7) | 2222 (17.1) | 8955 (17.2) | ||
| 2013-2016 | 1327 (10.2) | 1276 (9.8) | 1217 (10.2) | 1169 (9.8) | 1327 (10.2) | 5141 (9.9) | ||
| Parity | ||||||||
| 1 | 5940 (45.6) | 5945 (45.7) | 5474 (46.0) | 5590 (46.9) | 6006 (46.1) | 24690 (47.4) | ||
| 2 | 4589 (35.3) | 4643 (35.7) | 4151 (34.9) | 4163 (35.0) | 4525 (34.8) | 17734 (34.1) | ||
| ≥3 | 2488 (19.1) | 2429 (18.7) | 2283 (19.2) | 2155 (18.1) | 2488 (19.1) | 9651 (18.5) | ||
| Multiple birth pregnancy | 459 (3.5) | 409 (3.1) | 453 (3.8) | 638 (5.4) | 459 (3.5) | 1429 (2.7) | ||
| Smoking during pregnancy | 3378 (26.0) | 3226 (24.8) | 3120 (26.2) | 3017 (25.3) | 3379 (26.0) | 13205 (25.4) | ||
| Previous pregnancy with major birth defect | 196 (1.5) | 171 (1.3) | 181 (1.5) | 160 (1.3) | 196 (1.5) | 607 (1.2) | ||
| Antidiabetic drug use in past year | 170 (1.3) | 163 (1.3) | 170 (1.4) | 146 (1.2) | 170 (1.3) | 500 (1.0) | ||
| Drugs used for IVF in past 3 months | 489 (3.8) | 457 (3.5) | 487 (4.1) | 497 (4.2) | 489 (3.8) | 1766 (3.4) | ||
| No of drugs used in past year | ||||||||
| 1-2 | 3937 (30.3) | 3921 (30.1) | 3932 (33.0) | 3705 (31.1) | 4120 (31.7) | 16866 (32.4) | ||
| 3-4 | 3443 (26.5) | 3465 (26.6) | 3438 (28.9) | 3476 (29.2) | 3350 (25.7) | 13770 (26.4) | ||
| ≥5 | 4239 (32.6) | 4317 (33.2) | 4219 (35.4) | 4215 (35.4) | 3967 (30.5) | 15296 (29.4) | ||
| No of inpatient hospital admissions in past year | ||||||||
| 1 | 1540 (11.8) | 1491 (11.5) | 1444 (12.1) | 1321 (11.1) | 1540 (11.8) | 5464 (10.5) | ||
| 2 | 354 (2.7) | 342 (2.6) | 325 (2.7) | 286 (2.4) | 354 (2.7) | 1131 (2.2) | ||
| ≥3 | 112 (0.9) | 98 (0.8) | 105 (0.9) | 92 (0.8) | 112 (0.9) | 325 (0.6) | ||
| No of outpatient contacts in past year | ||||||||
| 1 | 1822 (14.0) | 1776 (13.6) | 1701 (14.3) | 1541 (12.9) | 1822 (14.0) | 6612 (12.7) | ||
| 2 | 659 (5.1) | 618 (4.8) | 621 (5.2) | 560 (4.7) | 659 (5.1) | 2080 (4.0) | ||
| ≥3 | 290 (2.2) | 271 (2.1) | 282 (2.4) | 235 (2.0) | 290 (2.2) | 945 (1.8) | ||
GA=gestational age (days since start of pregnancy), IQR=interquartile range, IVF=in vitro fertilisation.
Values are number (%) unless otherwise stated. Percentages might not total 100 because of rounding.
*
Income categorised into quarters.