Table 1 Characteristics of all pregnant women with placenta previa about retained products of concepts (RPOC)

Maternal age

  > 35 years

14

(58.3%)

140

(45.0%)

0.29

  < 35 years

10

(41.7%)

171

(55.0%)

Gestational age at delivery

  > 37 weeks

14

(58.3%)

199

(64.0%)

0.66

  < 37 weeks

10

(41.7%)

112

(36.0%)

Parity

 Primipara

9

(37.5%)

161

(51.8%)

0.21

 Multipara

15

(62.5%)

150

(48.2%)

In vitro fertilization pregnancy

 Yes

5

(20.8%)

38

(12.2%)

0.21

 No

19

(79.2%)

273

(87.8%)

Tocolytic agent use

 Yes

14

(58.3%)

124

(39.9%)

0.09

 No

10

(41.7%)

187

(60.1%)

Warning bleeding^a

 Yes

11

(45.8%)

86

(27.7%)

0.07

 No

13

(54.2%)

225

(72.3%)

Prior cesarean section

 Yes

11

(45.8%)

33

(10.6%)

 < 0.01

 No

13

(54.2%)

278

(89.4%)

The mode of cesarean section

 Emergency

6

(25.0%)

67

(21.5%)

0.80

 Elective

18

(75.0%)

244

(78.5%)

The classification of placenta previa

 major previa^b

18

(75.0%)

137

(44.0%)

 < 0.01

 minor previa^c

6

(25.0%)

174

(56.0%)

Main location of placenta

 Anterior wall

6

(25.0%)

34

(10.9%)

0.052

 Posterior wall

18

(75.0%)

277

(89.1%)

Placenta accreta spectrum

 Yes

9

(37.5%)

2

(0.6%)

 < 0.01

 No

15

(62.5%)

309

(99.4%)

Prior endometrial curettage

 Yes

8

(33.3%)

83

(26.7%)

0.48

 No

16

(66.7%)

228

(73.3%)

Magnetic resonance imaging after operation

 Yes

14

(58.3%)

14

(4.5%)

 < 0.01

 No

10

(41.7%)

297

(95.5%)

Intraoperative blood loss (ml)

 median (range)

1849

(724–4936)

1119

(265–3418)

 < 0.01

Postpartum hemorrhage (ml)

 median (range)

1868

(20–8748)

120

(0–3261)

 < 0.01

Total blood loss (ml)

 median (range)

4025

(789–13,172)

1270

(287–5121)

 < 0.01