Background
Methods
Study design
Data collection
Exposure variables, obstetric outcomes, and confounding factors
Statistical analyses
Results
All participants | Preconception dysmenorrhea group | Reference group | P value | |
---|---|---|---|---|
Variable | N = 80,242 | N = 8247 | N = 71,995 | |
Maternal medical background | ||||
Maternal age, % (N) | < 0.001 | |||
< 20 years | 0.6 (452) | 0.7 (58) | 0.5 (394) | |
20–29 years | 71.5 (57,371) | 74.3 (6127) | 71.2 (51,244) | |
≥30 years | 27.9 (22,419) | 25.0 (2062) | 28.3 (20,357) | |
Nulliparous, % (N) | 39.4 (31,621) | 49.0 (4039) | 38.3 (27,582) | < 0.001 |
Smoking during pregnancy, % (N) | 4.4 (3567) | 4.4 (364) | 4.4 (3203) | 0.883 |
Alcohol consumption, % (N) | 2.8 (2284) | 2.7 (221) | 2.9 (2063) | 0.337 |
Maternal education, % (N) | < 0.001 | |||
< 10 years | 4.3 (3457) | 4.4 (366) | 4.3 (3091) | |
10–12 years | 30.7 (24,598) | 26.9 (2219) | 31.1 (22,379) | |
13–16 years | 63.6 (50,997) | 66.9 (5521) | 63.2 (45,476) | |
≥17 years | 1.5 (1190) | 1.7 (141) | 1.5 (1049) | |
Annual household income, % (N) | 0.003 | |||
< 2,000,000 JPY | 5.5 (4375) | 5.1 (419) | 5.5 (3956) | |
2,000,000–5,999,999 JPY | 67.5 (54,172) | 66.4 (5474) | 67.6 (48,698) | |
6,000,000–9,999,999 JPY | 22.7 (18,248) | 24.3 (2004) | 22.6 (16,244) | |
≥10,000,000 JPY | 4.3 (3447) | 4.2 (350) | 4.3 (3097) | |
Maternal pre-pregnancy BMI, % (N) | < 0.001 | |||
< 18.5 kg/m2 | 15.7 (12,629) | 18.0 (1482) | 15.5 (11,147) | |
18.5–25.0 kg/m2 | 73.6 (59,089) | 72.2 (5957) | 73.8 (53,132) | |
≥25.0 kg/m2 | 10.6 (8524) | 9.8 (808) | 10.7 (7716) | |
Excessive GWG (≥ 12 kg), % (N) | 29.9 (23,976) | 29.9 (2462) | 29.9 (21,514) | 0.956 |
Obstetric outcomes | ||||
PTB before 37 weeks, % (N) | 4.4 (3507) | 4.6 (376) | 4.3 (3131) | 0.376 |
PTB before 34 weeks, % (N) | 0.8 (670) | 0.8 (69) | 0.8 (601) | 0.986 |
SGA, % (N) | 5.0 (3977) | 4.8 (397) | 5.0 (3580) | 0.529 |
pPROM, % (N) | 1.1 (858) | 1.1 (93) | 1.1 (765) | 0.586 |
HDP, % (N) | 3.1 (2465) | 2.9 (236) | 3.1 (2229) | 0.243 |
Obstetric outcomes | PTB < 37 weeks | PTB < 34 weeks | SGA | pPROM | HDP |
---|---|---|---|---|---|
Odds ratios (95% CI) | |||||
Exposure | |||||
Reference group | Ref | ||||
MD group N = 6784 | N = 292 (4.3%) | N = 56 (0.8%) | N = 332 (4.9%) | N = 79 (1.2%) | N = 194 (2.9%) |
cOR | 0.99 (0.88, 1.12) | 0.99 (0.75, 1.30) | 0.98 (0.88, 1.10) | 1.10 (0.87, 1.39) | 0.92 (0.79, 1.07) |
aOR | 1.00 (0.88, 1.13) | 0.99 (0.75, 1.30) | 0.96 (0.85, 1.07) | 1.07 (0.85, 1.35) | 0.90 (0.78, 1.05) |
SD group N = 1463 | N = 84 (5.7%) | N = 13 (0.9%) | N = 65 (4.4%) | N = 14 (1.0%) | N = 42 (2.9%) |
cOR | 1.34 (1.07, 1.68) | 1.07 (0.61, 1.85) | 0.89 (0.69, 1.14) | 0.90 (0.53, 1.53) | 0.93 (0.68, 1.26) |
aOR | 1.37 (1.10, 1.72) | 1.07 (0.62, 1.87) | 0.86 (0.67, 1.10) | 0.86 (0.50, 1.46) | 0.83 (0.61, 1.14) |
Obstetric outcomes | PTB < 37 weeks | PTB < 34 weeks | SGA | pPROM | HDP |
---|---|---|---|---|---|
Odds ratios (95% CI) | |||||
Exposure | |||||
Reference group | Ref | ||||
MPD group N = 5990 | N = 244 (4.1%) | N = 48 (0.8%) | N = 286 (4.8%) | N = 66 (1.1%) | N = 167 (2.8%) |
cOR | 0.93 (0.82, 1.07) | 0.96 (0.71, 1.29) | 0.96 (0.85, 1.08) | 1.04 (0.81, 1.34) | 0.90 (0.77, 1.05) |
aOR | 0.95 (0.83, 1.08) | 0.97 (0.72, 1.31) | 0.94 (0.83, 1.06) | 1.02 (0.79, 1.32) | 0.91 (0.77, 1.07) |
SPD group N = 1163 | N = 63 (5.4%) | N = 9 (0.8%) | N = 53 (4.6%) | N = 9 (0.8%) | N = 36 (3.1%) |
cOR | 1.26 (0.98, 1.63) | 0.93 (0.48, 1.79) | 0.91 (0.69, 1.20) | 0.73 (0.38, 1.41) | 1.00 (0.72, 1.40) |
aOR | 1.32 (1.02, 1.71) | 0.96 (0.50, 1.86) | 0.88 (0.67, 1.17) | 0.70 (0.36, 1.36) | 0.95 (0.68, 1.33) |