Table 3.
Unexpected medical visits and potential side effects by region: Aspirin Supplementation for Pregnancy Indicated Risk Reduction In Nulliparas trial
| Variable | Int P value | Total (n=11,879) | Africa (n=3735) | India (n=4818) | Pakistan (n=1625) | Guatemala (n=1701) |
|---|---|---|---|---|---|---|
| Participants with at least 1 unexpected emergency medical visit, RR (95% CI) | .002 | 0.98 (0.90–1.06) | 1.25 (1.09–1.43) | 1.00 (0.94–1.06) | 0.99 (0.88–1.11) | 0.74 (0.57–0.95) |
| Aspirin | 2015/5943 (33.9) | 368/1861 (19.8) | 1228/2411 (50.9) | 330/821 (40.2) | 89/850 (10.5) | |
| Placebo | 1974/5936 (33.3) | 297/1874 (15.8) | 1228/2407 (51.0) | 328/804 (40.8) | 121/851 (14.2) | |
| Biweekly monitoring of potential side effects | ||||||
| Participants with at least 1 potential side effect, RR (95% CI) | .423 | 1.01 (0.97–1.06) | 1.06 (0.97–1.17) | 0.99 (0.94–1.03) | 1.03 (0.97–1.08) | 0.98 (0.85–1.12) |
| Aspirin | 2947/5943 (49.6) | 625/1861 (33.6) | 1434/2411 (59.5) | 625/821 (76.1) | 263/850 (30.9) | |
| Placebo | 2910/5936 (49.0) | 591/1874 (31.5) | 1452/2407 (60.3) | 597/804 (74.3) | 270/851 (31.7) | |
| Participants with at least 1 episode of nausea, RR (95% CI) | .927 | 0.99 (0.92–1.06) | 1.00 (0.85–1.17) | 0.97 (0.89–1.04) | 1.00 (0.93–1.09) | 0.99 (0.80–1.22) |
| Aspirin | 1691/5943 (28.5) | 252/1861 (13.5) | 817/2411 (33.9) | 482/821 (58.7) | 140/850 (16.5) | |
| Placebo | 1711/5936 (28.8) | 255/1874 (13.6) | 844/2407 (35.1) | 470/804 (58.5) | 142/851 (16.7) | |
| Participants with at least 1 episode of vomiting, RR (95% CI) | .295 | 0.94 (0.86–1.03) | 0.94 (0.78–1.13) | 0.97 (0.90–1.05) | 1.05 (0.96–1.15) | 0.81 (0.61–1.09) |
| Aspirin | 1587/5943 (26.7) | 199/1861 (10.7) | 881/2411 (36.5) | 434/821 (52.9) | 73/850 (8.6) | |
| Placebo | 1611/5936 (27.1) | 213/1874 (11.4) | 903/2407 (37.5) | 405/804 (50.4) | 90/851 (10.6) | |
| Participants with at least 1 episode of rash or hives, RR (95% CI) | .007 | 1.19 (0.95–1.47) | 2.18 (1.25–3.80) | 1.33 (0.96–1.84) | 1.16 (0.90–1.51) | 0.58 (0.34–0.99) |
| Aspirin | 251/5943 (4.2) | 39/1861 (2.1) | 84/2411 (3.5) | 107/821 (13.0) | 21/850 (2.5) | |
| Placebo | 207/5936 (3.5) | 18/1874 (1.0) | 63/2407 (2.6) | 90/804 (11.2) | 36/851 (4.2) | |
| Participants with at least 1 episode of diarrhea, RR (95% CI) | .919 | 1.05 (0.91–1.23) | 1.15 (0.85–1.55) | 1.06 (0.89–1.26) | 0.98 (0.69–1.40) | 1.03 (0.73–1.46) |
| Aspirin | 452/5943 (7.6) | 88/1861 (4.7) | 246/2411 (10.2) | 56/821 (6.8) | 62/850 (7.3) | |
| Placebo | 425/5936 (7.2) | 77/1874 (4.1) | 232/2407 (9.6) | 56/804 (7.0) | 60/851 (7.1) | |
| Participants with at least 1 episode of gastritis, RR (95% CI) | .380 | 0.99 (0.89–1.10) | 1.07 (0.84–1.36) | 0.91 (0.80–1.02) | 0.90 (0.76–1.05) | 1.10 (0.84–1.44) |
| Aspirin | 853/5943 (14.4) | 124/1861 (6.7) | 415/2411 (17.2) | 214/821 (26.1) | 100/850 (11.8) | |
| Placebo | 899/5936 (15.1) | 117/1874 (6.2) | 457/2407 (19.0) | 234/804 (29.1) | 91/851 (10.7) | |
| Participants with at least 1 episode of vaginal bleeding, RR (95% CI) | .349 | 0.83 (0.69–1.02) | 1.05 (0.71–1.54) | 0.92 (0.69–1.21) | 0.85 (0.59–1.24) | 0.59 (0.36–0.98) |
| Aspirin | 214/5943 (3.6) | 52/1861 (2.8) | 91/2411 (3.8) | 48/821 (5.8) | 23/850 (2.7) | |
| Placebo | 243/5936 (4.1) | 50/1874 (2.7) | 99/2407 (4.1) | 55/804 (6.8) | 39/851 (4.6) | |
| Participants with at least 1 episode of allergic reaction, RR (95% CI) | .823 | 0.84 (0.39–1.78) | 1.34 (0.47–3.86) | 0.75 (0.26–2.15) | 0.49 (0.04–5.39) | 1.00 (0.35–2.84) |
| Aspirin | 22/5943 (0.4) | 8/1861 (0.4) | 6/2411 (0.2) | 1/821 (0.1) | 7/850 (0.8) | |
| Placebo | 23/5936 (0.4) | 6/1874 (0.3) | 8/2407 (0.3) | 2/804 (0.2) | 7/851 (0.8) | |
| Participants with at least 1 episode of other potential side effect, RR (95% CI) | .677 | 1.03 (0.94–1.13) | 1.10 (0.95–1.28) | 1.00 (0.94–1.07) | 0.98 (0.86–1.12) | 1.03 (0.76–1.39) |
| Aspirin | 1673/5943 (28.2) | 305/1861 (16.4) | 1013/2411 (42.0) | 277/821 (33.7) | 78/850 (9.2) | |
| Placebo | 1640/5936 (27.6) | 279/1874 (14.9) | 1008/2407 (41.9) | 277/804 (34.5) | 76/851 (8.9) |
Data are presented number/total number (percentage), unless otherwise specified. Unexpected emergency medical visits may have been related to potential side effects but are analyzed separately from potential side effects reported at biweekly visits. The denominator is any participant included in the safety population, and the numerator is participants with at least 1 report of the event. The most commonly reported other potential side effects include cold/cough or fever, abdominal pain or discomfort, and headache.
CI, confidence interval; Int, interaction; RR, relative risk.
Short. Aspirin safety during pregnancy in low- and middle-income countries. Am J Obstet Gynecol Glob Rep 2021.