Table 2 Maternal and pregnancy characteristics by site for the analysis population

Maternal age

  < 20

23,462 (16.2)

4,935 (22.1)

4,651 (23.9)

4,870 (21.5)

4,300 (17.3)

2,348 (15.0)

564 (2.9)

566 (3.6)

1,228 (25.2)

 20–35

113,304 (78.0)

15,332 (68.7)

13,309 (68.4)

16,642 (73.6)

18,114 (72.8)

13,196 (84.5)

18,919 (96.4)

14,323 (90.3)

3,469 (71.3)

  > 35

8,440 (5.8)

2,047 (9.2)

1,490 (7.7)

1,095 (4.8)

2,458 (9.9)

69 (0.4)

138 (0.7)

975 (6.1)

168 (3.5)

Maternal education

 No formal education

27,165 (18.7)

7,895 (35.4)

1,276 (6.6)

212 (0.9)

2,379 (9.6)

1,377 (8.8)

363 (1.9)

13,346 (84.1)

317 (6.5)

 Primary/secondary

107,046 (73.7)

14,350 (64.3)

17,823 (91.6)

20,003 (88.5)

20,290 (81.6)

12,165 (77.9)

15,881 (80.9)

2,316 (14.6)

4,218 (86.7)

 University + 

10,995 (7.6)

69 (0.3)

351 (1.8)

2,392 (10.6)

2,203 (8.9)

2,071 (13.3)

3,377 (17.2)

202 (1.3)

330 (6.8)

Parity

 0

47,785 (32.9)

4,415 (19.8)

6,403 (32.9)

7,768 (34.4)

7,828 (31.5)

6,026 (38.6)

9,953 (50.7)

3,472 (21.9)

1,920 (39.5)

 1

38,439 (26.5)

3,581 (16.0)

4,640 (23.9)

5,345 (23.6)

6,206 (25.0)

5,921 (37.9)

7,827 (39.9)

3,137 (19.8)

1,782 (36.6)

 2

21,679 (14.9)

3,058 (13.7)

3,313 (17.0)

3,585 (15.9)

4,161 (16.7)

2,657 (17.0)

1,477 (7.5)

2,561 (16.1)

867 (17.8)

 3

13,513 (9.3)

3,073 (13.8)

2,263 (11.6)

2,521 (11.2)

2,360 (9.5)

724 (4.6)

267 (1.4)

2,064 (13.0)

241 (5.0)

 4 + 

23,790 (16.4)

8,187 (36.7)

2,831 (14.6)

3,388 (15.0)

4,317 (17.4)

285 (1.8)

97 (0.5)

4,630 (29.2)

55 (1.1)

Maternal height in cm, mean (std)

154.2 (7.5)

156.5 (6.6)

158.0 (6.5)

160.3 (6.7)

146.8 (5.4)

152.0 (5.5)

152.7 (5.6)

154.5 (5.6)

151.2 (6.4)

Maternal weight in kg, mean (std)

53.7 (10.5)

52.6 (7.3)

59.5 (10.6)

61.1 (9.1)

56.5 (9.8)

46.8 (8.2)

46.1 (7.9)

50.1 (9.5)

52.8 (9.7)

Socioeconomic status score

  < 34

50,593 (34.8)

21,101 (94.6)

7,819 (40.2)

15,428 (68.2)

1,543 (6.2)

245 (1.6)

249 (1.3)

3,809 (24.0)

399 (8.2)

 34–65

62,074 (42.7)

1,213 (5.4)

10,337 (53.1)

6,938 (30.7)

15,791 (63.5)

7,188 (46.0)

8,099 (41.3)

8,632 (54.4)

3,876 (79.7)

 66 + 

32,539 (22.4)

0 (0.0)

1,294 (6.7)

241 (1.1)

7,538 (30.3)

8,180 (52.4)

11,273 (57.5)

3,423 (21.6)

590 (12.1)

Previous livebirth

 Yes

93,797 (64.6)

17,231 (77.2)

12,578 (64.7)

14,211 (62.9)

16,329 (65.7)

9,246 (59.2)

9,352 (47.7)

12,054 (76.0)

2,796 (57.5)

 No

3,624 (2.5)

668 (3.0)

469 (2.4)

628 (2.8)

715 (2.9)

341 (2.2)

316 (1.6)

338 (2.1)

149 (3.1)

 No previous pregnancy lasting 20 + weeks

47,785 (32.9)

4,415 (19.8)

6,403 (32.9)

7,768 (34.4)

7,828 (31.5)

6,026 (38.6)

9,953 (50.7)

3,472 (21.9)

1,920 (39.5)

Number of antenatal care visits

 0

4,250 (2.9)

438 (2.0)

19 (0.1)

198 (0.9)

1,031 (4.1)

1 (0.0)

6 (0.0)

378 (2.4)

2,179 (44.8)

 1–3

47,759 (32.9)

11,303 (50.7)

6,305 (32.4)

7,814 (34.6)

8,088 (32.5)

2,349 (15.0)

1,483 (7.6)

8,187 (51.6)

2,230 (45.8)

 4 + 

93,197 (64.2)

10,573 (47.4)

13,126 (67.5)

14,595 (64.6)

15,753 (63.3)

13,263 (84.9)

18,132 (92.4)

7,299 (46.0)

456 (9.4)

Iron supplement

138,318 (95.3)

21,165 (94.9)

19,405 (99.8)

22,369 (98.9)

23,818 (95.8)

15,546 (99.6)

19,559 (99.7)

12,572 (79.2)

3,884 (79.8)

Vitamin or calcium supplement

111,436 (76.7)

3,151 (14.1)

16,284 (83.7)

22,393 (99.1)

17,924 (72.1)

15,411 (98.7)

19,566 (99.7)

12,909 (81.4)

3,798 (78.1)

Hypertensive disorder

3,332 (2.3)

18 (0.1)

237 (1.2)

113 (0.5)

1,022 (4.1)

791 (5.1)

526 (2.7)

455 (2.9)

170 (3.5)

Severe antepartum hemorrhage

904 (0.6)

73 (0.3)

116 (0.6)

182 (0.8)

43 (0.2)

100 (0.6)

53 (0.3)

284 (1.8)

53 (1.1)

Severe infection during pregnancy

1,936 (1.3)

703 (3.2)

38 (0.2)

271 (1.2)

248 (1.0)

76 (0.5)

126 (0.6)

452 (2.8)

22 (0.5)