Table 1. Characteristics of women who used and did not use non-steroidal anti-inflammatory drugs (NSAIDs) in gestational weeks 0–12.a .
| Characteristic | Subcategory | NSAID used (n = 3,023) | No NSAID used (n = 64,074) |
| Age at delivery | <20 y | 42 (1.4) | 689 (1.1) |
| 20–29 y | 1,320 (43.7) | 28,406 (44.3) | |
| 30–39 y | 1,607 (53.2) | 33,774 (52.7) | |
| ≥40 y | 54 (1.8) | 1,205 (1.9) | |
| Education | <10 y | 96 (3.2) | 1,989 (3.1) |
| 10–12 y | 1,134 (37.5) | 21,575 (33.7) | |
| >12 y | 1,639 (54.2) | 37,109 (57.9) | |
| Other | 62 (2.1) | 1,091 (1.7) | |
| Missing | 92 (3.0) | 2,310 (3.6) | |
| Married/cohabiting | Married/cohabiting | 2,862 (94.7) | 61,541 (96.0) |
| Other | 143 (4.7) | 2,232 (3.5) | |
| Missing | 18 (0.6) | 301 (0.5) | |
| Parity | 0 previous live births | 1,393 (46.1) | 27,732 (43.3) |
| ≥1 previous live births | 1,629 (53.9) | 36,337 (56.7) | |
| Missing | 1 (0.0) | 5 (0.0) | |
| Previous miscarriages, stillbirth, or induced abortions | None | 1,874 (62.0) | 41,175 (64.3) |
| Miscarriage or stillbirth | 572 (18.9) | 11,661 (18.2) | |
| Induced abortion | 401 (13.3) | 7,190 (11.2) | |
| Induced abortion and miscarriage or stillbirth | 123 (4.1) | 2,347 (3.7) | |
| Missing | 53 (1.8) | 1,701 (2.7) | |
| Prepregnancy body-mass indexb | Underweight | 74 (2.4) | 1,947 (3.0) |
| Normal weight | 1,795 (59.4) | 40,534 (63.2) | |
| Overweight | 684 (22.6) | 13,782 (21.5) | |
| Obese | 398 (13.2) | 5,917 (9.2) | |
| Missing | 72 (2.4) | 1,894 (3.0) | |
| Any folic acid usec | Yes | 1,916 (63.4) | 40,611 (63.4) |
| No | 1,107 (36.6) | 23,463 (36.6) | |
| Pregnancy outcome | Live birth, still alive | 2,993 (99.0) | 63,622 (99.3) |
| Live birth, died during follow-up | 10 (0.3) | 158 (0.2) | |
| Stillbirth | 19 (0.6) | 271 (0.4) | |
| Induced abortion | 1 (0.0) | 23 (0.0) |
a
Data from the Norwegian Mother and Child Cohort Study, 1999–2006. All data are presented as a number (%). Percentages may not add up to 100% due to rounding.
b
The body-mass index is the weight in kilograms divided by the square of the height in meters: underweight: <18.5 kg/m2, normal weight: 18.5–24.9 kg/m2; overweight: 25.0–29.9 kg/m2, obese: ≥30 kg/m2.
c
Folic acid use is reported from the 4 weeks prior to pregnancy through week 8 of gestation.