Table 1 Baseline demographic and clinical characteristics by infant gender

Infants (%)¹

297,509

154,790 (52.03)

142,719 (47.97)

Maternal age, N (%)^2,3

297,229

154,622

142,607

0.1934

 < 20

18,151 (6.1)

9325 (6.0)

8,826 (6.2)

 20—35

273,435 (92.0)

142,340 (92.1)

131,095 (91.9)

 > 35

5643 (1.9)

2957 (1.9)

2686 (1.9)

Maternal education, N (%)^2,3

296,599

154,306

142,293

0.2556

 No formal schooling

100,006 (33.7)

52,010 (33.7)

47,996 (33.7)

 Primary or Secondary

168,503 (56.8)

87,759 (56.9)

80,744 (56.7)

 University+

28,090 (9.5)

14,537 (9.4)

13,553 (9.5)

Parity, N (%)^2,3

294,655

153,310

141,345

0.6322

 0

107,334 (36.4)

55,783 (36.4)

51,551 (36.5)

 1–2

134,820 (45.8)

70,097 (45.7)

64,723 (45.8)

 3–4

29,601 (10.0)

15,511 (10.1)

14,090 (10.0)

 ≥ 5

22,900 (7.8)

11,919 (7.8)

10,981 (7.8)

Antenatal care, N (%)^2,3

218,046

113,154

104,892

0.2955

 ≥ 4 ANC visits

134,446 (61.7)

69,784 (61.7)

64,662 (61.6)

 < 4 ANC visits

83,600 (38.3)

43,370 (38.3)

40,230 (38.4)

Trimester of first ANC visit, N (%)^2,3

259,453

135,254

124,199

0.0050

 First (0–14 weeks)

170,639 (65.8)

88,475 (65.4)

82,164 (66.2)

 Second (15–28 weeks)

65,488 (25.2)

34,465 (25.5)

31,023 (25.0)

 Third (29–42 weeks)

23,326 (9.0)

12,314 (9.1)

11,012 (8.9)

Complications of pregnancy, N (%)^2,3

 Evidence of hypertensive disease/severe pre-eclampsia/eclampsia

10,072/297,108 (3.4)

5260/154,604 (3.4)

4812/142,504 (3.4)

0.4986

 Severe antepartum hemorrhage

4341/297,198 (1.5)

2361/154,652 (1.5)

980/142,546 (1.4)

0.0022

 BMI ≥ 25

21,660/291,335 (7.4)

11,313/151,628 (7.5)

10,347/139,707 (7.4)

0.5177

 Hemoglobin measured at/before enrollment < 8 mg/dl

5762/212,960 (2.7)

2930/110,629 (2.6)

2832/102,331 (2.8)

0.1905

 Hemoglobin measured after enrollment and before delivery < 8 mg/dl

2794/79,063 (3.5)

1424/40,865 (3.5)

1370/38,198 (3.6)

0.4455

 Multiple birth

5297/297,444 (1.8)

2,704/154,748 (1.7)

2593/142,696 (1.8)

0.1330