Background
Methods
Study population and data sources
Ascertainment of diseases
Diseases | ICD10-AM codes |
---|---|
Cardiac diseases | Diagnoses: I00-02, I05-09, I10-I15, I20-25, I26-28, I30-52, O90.3, Q20-Q25 (when assessing the birth admission records codes such as I21, I24, I30, I33, I40, I46 and I50 were excluded) Procedure: 38603-00, 38600-00, 38256-00, 38256-01, 38256-02, 38278-00, 38278-01, 38284-00, 90202-00, 38470-00, 38473-00, 38281-01, 38281-02, 38281-03, 38281-04, 38281-05, 38281-06, 38281-07, 38281-07, 38281-08, 38281-09, 38281-10, 38281-00, 38278-02, 38456-07, 90203-00, 38284-01, 90219-00, 38281-11, 38281-12, 38212-00, 38209-00, 38200-00, 38203-00, 38206-00, 35324-00, 35315-00, 35315-01, 35304-01, 35305-00, 35304-00, 35305-01, 35310-00, 35310-01, 35310-03, 35310-04, 35310-02, 35310-05 (assessed only on hospital records before the birth admission) |
Chronic kidney disease | Diagnoses: E10.2, E11.2, E12.2, E13.2, E14.2, I12-13, I15.0, I15.1, N00-08, N11-12, N14-16, N18-19, N25-28, N39.1, N39.2, Q60-63, T82.4, T86.1, Z49, Z94.0, Z99.2 Procedure: 36561-00, 36503-00, 36503-01, 13100-06, 13100-07, 13100-08, 13100-00 (assessed only on hospital records before the birth admission) |
Asthma/Chronic obstructive pulmonary disease | Diagnoses: J40-J47, J98, R05 |
Psychiatric disorders | Diagnoses: F20-F25, F28-F34, F38, F39, F53.1 |
Pre-existing hypertension | Diagnoses: O10, O11, I10-I15 or chronic hypertension* in birth data |
Pre-existing diabetes | Diagnoses: O24.0-O24.3, E10-E14 (excluded records that were also coded with O24.4) |
Thyroid disorders | Diagnoses: E00-E07, E89.0, O90.5 Procedure: 30075-03, 30094-10, 30296-00, 30297-00, 30297-01, 30306-00, 30308-00, 30309-00, 30310-00, 36503-01, 90041-00, 90046-00, 90046-01, 90047-00, 90047-01, 90047-02 (assessed only on hospital records before the birth admission) |
Autoimmune diseases^ | Diagnoses: K50, K51, M32, L93, D69.3, G35, L40, E06.3, M05, M06, K90.0, I77.6, I80, L95, M30, M31, D51.0, G70.0, K75.4, M08.1, M45, M33.2, K74.3, M33.0, M33.1 |
Obstetric haemorrhage&
| Diagnoses: O72, O67, O46.0, O44.1, O43.2, Z51.3, D62 Procedure: 13706-01, 13706-02, 13706-03, 92061-00, 92062-00, 90482-00, 90483-00 |
Data analysis
Results
Time sequence | No. (%) of women (N = 53,438) | No. (%) of hospital records (N = 113,478) |
---|---|---|
Transfer admission* | 1,806 (3.4%) | 1,831 (1.6%) |
At birth admission | 53,438 (100%) | 53,438 (47.1%) |
During pregnancy | 15,284 (28.6%) | 25,351 (22.3%) |
Estimated day preceding pregnancy to <2 years prior to delivery | 9,845 (18.4%) | 16,640 (14.7%) |
2 to <3 years prior to delivery | 4,662 (8.7%) | 6,930 (6.1%) |
3 to <4 years prior to delivery | 3,672 (6.9%) | 5,158 (4.5%) |
4 to <5 years prior to delivery | 2,954 (5.5%) | 4,130 (3.6%) |
Lookback period: | ||||||
---|---|---|---|---|---|---|
'Birth' | 'Pregnancy' | '2 years' | '3 years' | '4 years' | '5 years' | |
Cardiac diseases
| ||||||
No. | 194 | 273 | 357 | 392 | 425 | 445 |
% of total cases | 43.6% | 61.3% | 80.2% | 88.1% | 95.5% | 100.0% |
Prevalence | 0.36% | 0.51% | 0.67% | 0.73% | 0.80% | 0.83% |
Chronic renal disease
| ||||||
No. | 67 | 217 | 279 | 324 | 354 | 377 |
% of total cases | 17.8% | 57.6% | 74.0% | 85.9% | 93.9% | 100.0% |
Prevalence | 0.13% | 0.41% | 0.52% | 0.61% | 0.66% | 0.71% |
Asthma/COPD*
| ||||||
No. | 473 | 682 | 984 | 1,087 | 1,175 | 1,255 |
% of total cases | 37.7% | 54.3% | 78.4% | 86.6% | 93.6% | 100.0% |
Prevalence | 0.89% | 1.28% | 1.84% | 2.03% | 2.20% | 2.35% |
Psychiatric disorders
| ||||||
No. | 325 | 424 | 619 | 705 | 783 | 829 |
% of total cases | 39.2% | 51.1% | 74.7% | 85.0% | 94.5% | 100.0% |
Prevalence | 0.61% | 0.79% | 1.16% | 1.32% | 1.47% | 1.55% |
Pre-existing hypertension
| ||||||
No. | 420 | 515 | 535 | 540 | 546 | 549 |
% of total cases | 76.5% | 93.8% | 97.4% | 98.4% | 99.5% | 100.0% |
Prevalence | 0.79% | 0.96% | 1.00% | 1.01% | 1.02% | 1.03% |
Pre-existing diabetes
| ||||||
No. | 250 | 265 | 289 | 297 | 300 | 305 |
% of total cases | 82.0% | 86.9% | 94.8% | 97.4% | 98.4% | 100.0% |
Prevalence | 0.47% | 0.50% | 0.54% | 0.56% | 0.56% | 0.57% |
Thyroid disorders
| ||||||
No. | 173 | 204 | 240 | 253 | 266 | 275 |
% of total cases | 62.9% | 74.2% | 87.3% | 92.0% | 96.7% | 100.0% |
Prevalence | 0.32% | 0.38% | 0.45% | 0.47% | 0.50% | 0.51% |
Autoimmune diseases^
| ||||||
No. | 202 | 247 | 323 | 374 | 401 | 426 |
% of total cases | 47.4% | 58.0% | 75.8% | 87.8% | 94.1% | 100.0% |
Prevalence | 0.38% | 0.46% | 0.60% | 0.70% | 0.75% | 0.80% |
Type of diseases | Lookback periods: | |||||
---|---|---|---|---|---|---|
'Birth' | 'Pregnancy' | '2 years' | '3 years' | '4 years' | '5 years' | |
Cardiac diseases
| ||||||
OR (95% CI) | 1.55 (1.03-2.33) | 1.45 (1.02-2.07) | 1.42 (1.04-1.93) | 1.34 (0.99-1.81) | 1.28 (0.95-1.72) | 1.21 (0.90-1.63) |
P value | 0.04 | 0.04 | 0.03 | 0.06 | 0.11 | 0.21 |
Chronic renal disease
| ||||||
OR (95% CI) | 3.00 (1.71-5.26) | 1.68 (1.16-2.45) | 1.58 (1.13-2.22) | 1.49 (1.08-2.06) | 1.45 (1.07-1.99) | 1.42 (1.05-1.92) |
P value | <0.001 | 0.007 | 0.008 | 0.02 | 0.02 | 0.02 |
Psychiatric disorders
| ||||||
OR (95% CI) | 1.67 (1.22-2.27) | 1.50 (1.13-1.98) | 1.36 (1.07-1.73) | 1.30 (1.03-1.63) | 1.28 (1.02-1.59) | 1.24 (1.00-1.54) |
P value | 0.001 | 0.005 | 0.01 | 0.03 | 0.03 | 0.05 |
Pre-existing hypertension
| ||||||
OR (95% CI) | 1.22 (0.90-1.65) | 1.18 (0.89-1.55) | 1.17 (0.89-1.54) | 1.16 (0.88-1.52) | 1.15 (0.87-1.51) | 1.14 (0.87-1.50) |
P value | 0.20 | 0.25 | 0.25 | 0.28 | 0.32 | 0.35 |
Pre-existing diabetes
| ||||||
OR (95% CI) | 1.06 (0.70-1.60) | 1.12 (0.76-1.66) | 1.10 (0.76-1.61) | 1.15 (0.80-1.66) | 1.14 (0.79-1.64) | 1.12 (0.77-1.61) |
P value | 0.79 | 0.52 | 0.61 | 0.46 | 0.49 | 0.56 |
Asthma/COPD*
| ||||||
OR (95% CI) | 1.22 (0.92-1.63) | 1.20 (0.94-1.53) | 1.19 (0.98-1.46) | 1.16 (0.95-1.41) | 1.13 (0.94-1.37) | 1.09 (0.90-1.31) |
P value | 0.18 | 0.15 | 0.09 | 0.14 | 0.20 | 0.37 |
Thyroid disorders
| ||||||
OR (95% CI) | 1.38 (0.88-2.16) | 1.39 (0.92-2.10) | 1.41 (0.97-2.06) | 1.38 (0.95-2.00) | 1.39 (0.97-2.00) | 1.34 (0.93-1.92) |
P value | 0.16 | 0.12 | 0.07 | 0.09 | 0.07 | 0.11 |
Autoimmune diseases^
| ||||||
OR (95% CI) | 1.34 (0.88-2.04) | 1.31 (0.89-1.92) | 1.23 (0.87-1.73) | 1.17 (0.84-1.62) | 1.23 (0.90-1.68) | 1.24 (0.92-1.67) |
P value | 0.17 | 0.17 | 0.24 | 0.35 | 0.19 | 0.17 |
Model 1* (n = 53,191): | Model 2**(n = 53,191): | |||
---|---|---|---|---|
Covariates: | OR (95%CI) | P | OR (95%CI) | P |
Chronic renal diseases (yes) | 2.85 (1.58-5.12) | <0.001 | 1.63 (1.11-2.40) | 0.01 |
Psychiatric disorders (yes) | 1.48 (1.08-2.02) | 0.01 | 1.38 (1.04-1.84) | 0.03 |
Baby's gender (female) | 1.15 (1.09-1.22) | <0.001 | 1.15 (1.09-1.22) | <0.001 |
Birth weight (per 100 g) | 1.05 (1.05-1.06) | <0.001 | 1.05 (1.05-1.06) | <0.001 |
Multiple births (yes) | 2.28 (1.86-2.78) | <0.001 | 2.27 (1.86-2.78) | <0.001 |
Gestational age
| <0.001 | <0.001 | ||
Preterm (20 - 36 weeks) | 2.11 (1.85-2.40) | 2.12 (1.86-2.41) | ||
Term (37 - 41 weeks) | 1.00 | 1.00 | ||
Postterm (≥42 weeks) | 0.99 (0.82-1.19) | 0.99 (0.82-1.20) | ||
Maternal age
| 0.11 | 0.10 | ||
<20 years | 1.03 (0.92-1.15) | 1.02 (0.91-1.15) | ||
20 - 34 years | 1.00 | 1.00 | ||
≥35 years | 1.10 (1.01-1.19) | 1.10 (1.01-1.19) | ||
Onset of labor + mode of delivery
| <0.001 | <0.001 | ||
Elective CS^ (no labor) | 1.07 (0.96-1.20) | 1.08 (0.96-1.20) | ||
Emergency CS + induction/augmentation | 0.87 (0.78-0.98) | 0.88 (0.78-0.98) | ||
Instrumental + induction/augmentation | 1.99 (1.81-2.19) | 1.99 (1.82-2.19) | ||
Vaginal + induction/augmentation | 1.43 (1.31-1.56) | 1.43 (1.31-1.56) | ||
Emergency CS (spontaneous labor) | 0.77 (0.67-0.90) | 0.77 (0.67-0.90) | ||
Instrumental (spontaneous labor) | 1.58 (1.40-1.77) | 1.58 (1.41-1.77) | ||
Vaginal (spontaneous labor) | 1.00 | 1.00 | ||
Type of hospital (tertiary vs. other) | 1.54 (1.45-1.64) | <0.001 | 1.54 (1.45-1.64) | <0.001 |
C-statistic (95% CI) |
C-statistic (95% CI) | |||
Predictive ability
| 0.6240 (0.6157-0.6322) | 0.6238 (0.6156-0.6320) | ||
P for comparing the two correlated C statistics: 0.61 |