Table 1 |
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|
Maternal characteristics and rate of placenta previa (per 1000 births) in second births |
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|
Number (%) of births |
Placenta Previa Rate |
Unadjusted OR (95% CI)** |
Adjusted OR (95% CI)** |
|
|
|
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|
Previous cesarean delivery |
p < 0.001 |
p < 0.001 |
||
|
Yes |
86055 (21.5) |
8.7 |
1.88 (1.71-2.07) |
1.60 (1.44-1.76) |
|
No |
313619 (78.5) |
4.4 |
- |
- |
|
Previous placenta previa |
p < 0.001 |
p < 0.001 |
||
|
Yes |
1429 (0.4) |
43.4 |
7.74 (5.80-10.34) |
4.77 (3.55-6.42) |
|
No |
398245 (99.6) |
5.2 |
- |
- |
|
Maternal age* |
p < 0.001 |
p < 0.001 |
||
|
<20 |
15393 (3.9) |
1.9 |
0.56 (0.38-0.82) |
0.58 (0.39-0.86) |
|
20-29 |
191151 (47.8) |
3.6 |
- |
- |
|
30-39 |
184237 (46.1) |
7.1 |
2.01 (1.82-2.22) |
1.83 (1.65-2.05) |
|
≥40 |
8887 (2.2) |
13.2 |
3.60 (2.90-4.46) |
3.01 (2.41-3.75) |
|
Ethnicity* |
p = 0.053 |
p = 0.387 |
||
|
White |
275181 (80.4) |
5.6 |
- |
- |
|
Asian |
42486 (12.4) |
4.8 |
0.86 (0.74-0.99) |
1.03 (0.89-1.21) |
|
Black |
12158 (3.6) |
5.0 |
0.91 (0.70-1.17) |
0.96 (0.74-1.25) |
|
Other |
12448 (3.6) |
6.7 |
1.19 (0.96-1.50) |
1.22 (0.97-1.52) |
|
Deprivation* |
p < 0.001 |
p = 0.180 |
||
|
Q1 Most deprived |
122039 (30.6) |
4.0 |
- |
- |
|
Q2 |
90740 (22.8) |
5.1 |
1.30 (1.14-1.49) |
1.10 (0.96-1.26) |
|
Q3 |
85913 (21.6) |
6.1 |
1.52 (1.33-1.73) |
1.15 (0.99-1.32) |
|
Q4 Least deprived |
99403 (25.0) |
6.5 |
1.63 (1.44-1.85) |
1.16 (1.01-1.33) |
|
Pre-existing hypertension |
p = 0.080 |
p = 0.026 |
||
|
Yes |
5730 (1.4) |
3.5 |
0.69 (0.44-1.08) |
0.62 (0.39-0.98) |
|
No |
393944 (98.6) |
5.4 |
- |
- |
|
Gestational hypertension*** |
p = 0.322 |
p = 0.098 |
||
|
Yes |
8464 (2.1) |
5.1 |
0.85 (0.60-1.19) |
0.76 (0.54-1.07) |
|
No |
391210 (97.9) |
5.3 |
- |
- |
|
Gestational diabetes |
p = 0.337 |
p = 0.892 |
||
|
Yes |
5586 (1.4) |
5.9 |
1.19 (0.84-1.69) |
0.98 (0.69-1.39) |
|
No |
394088 (98.6) |
5.3 |
- |
- |
|
Polyhydramnios |
p = 0.003 |
p = 0.009 |
||
|
Yes |
1985 (0.5) |
11.1 |
2.11 (1.35-3.28) |
1.92 (1.23-3.00) |
|
No |
397689 (99.5) |
5.3 |
- |
- |
|
Inter-birth interval |
p < 0.001 |
p < 0.001 |
||
|
<1 |
7511 (1.9) |
6.4 |
1.38 (1.02-1.87) |
2.08 (1.53-2.83) |
|
1 to 2 |
120803 (30.2) |
4.8 |
0.92 (0.81-1.03) |
1.01 (0.90-1.14) |
|
2 to 3 |
133834 (33.5) |
5.2 |
- |
- |
|
3 to 4 |
73992 (18.5) |
5.5 |
1.08 (0.95-1.23) |
1.08 (0.94-1.23) |
|
4 to 5 |
35557 (8.9) |
6.1 |
1.19 (1.01-1.40) |
1.19 (1.01-1.40) |
|
≥5 |
27977 (7.0) |
6.6 |
1.29 (1.09-1.53) |
1.32 (1.11-1.57) |
|
|
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|
* Not including missing values (Maternal age n = 6, 0.0%; Deprivation n = 1549, 0.4%; Ethnicity n = 57401, 14.6% of data missing) ** The model was adjusted for all the variables presented in the table. P-values from the likelihood ratio test *** Gestational hypertension includes pre-eclampsia and eclampsia |
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|
Gurol-Urganci et al. BMC Pregnancy and Childbirth 2011 11:95 doi:10.1186/1471-2393-11-95 |
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