Table 1 Distribution of independent variables based on LBW in urban and rural India

Grouping factor

 Region

  Central

19.88 (11,181)

18.83 (2251)

20.16 (8929)

  East

17.61 (9027)

16.98 (1587)

17.75 (7441)

  North

18.71 (5415)

19.20 (1760)

18.49 (3656)

  Northeast

14.93 (1121)

13.84 (160)

15.14 (962)

  South

16.04 (6026)

15.16 (2238)

16.60 (3788)

  West

19.48 (5397)

17.87 (2052)

20.63 (3345)

  χ²-value [p-value]

326.12 [< 0.001]

102.28 [< 0.001]

246.47 [< 0.001]

Explanatory factors

 Religion

  Hindu

18.55 (30,987)

17.93 (7672)

18.76 (23,315)

  Muslim

16.83 (5534)

15.88 (1963)

17.40 (3571)

  Christian

15.85 (691)

15.11 (199)

16.17 (492)

  Other^a

19.35 (955)

15.21 (213)

21.00 (742)

  χ²-value [p-value]

75.18 [< 0.001]

37.48 [< 0.001]

46.86 [< 0.001]

 Social category

  Schedule tribe

18.76 (3893)

14.71 (362)

19.30 (3531)

  Schedule caste

19.54 (9328)

18.74 (2146)

19.79 (7182)

  OBC

17.79 (16,171)

17.30 (4369)

17.98 (11,802)

  General

17.32 (6627)

16.34 (2477)

17.96 (4151)

  χ²-value [p-value]

91.90 [< 0.001]

37.80 [< 0.001]

62.89 [< 0.001]

 Birth order

  1st

18.92 (16,090)

17.44 (4442)

19.56 (11,649)

  2nd

17.50 (12,531)

16.61 (3515)

17.87 (9017)

  3rd

17.75 (5470)

17.54 (1270)

17.82 (4199)

   ≥ 4th

18.73 (4075)

20.53 (820)

18.32 (3255)

  χ²-value [p-value]

61.45 [< 0.001]

36.55 [< 0.001]

64.33 [< 0.001]

 Place of delivery

  Home

21.56 (2660)

20.83 (370)

21.68 (2290)

  Institution

18.03 (35,430)

17.23 (9648)

18.35 (25,782)

  χ²-value [p-value]

96.75 [< 0.001]

15.58 [< 0.001]

71.83 [< 0.001]

 Family size

   ≤ 4

18.65 (10,176)

16.83 (2970)

19.52 (7206)

   > 4

18.10 (27,990)

17.59 (7077)

18.28 (20,914)

  χ²-value [p-value]

8.30 [0.004]

4.97 [0.026]

28.65 [< 0.001]

 Wealth Index

  Poor

20.25 (18,463)

21.01 (1505)

20.18 (16,958)

  Middle

17.47 (7378)

18.48 (1817)

17.17 (5561)

  Rich

16.26 (12,325)

16.45 (6725)

16.04 (5601)

  χ²-value [p-value]

461.96 [< 0.001]

98.72 [< 0.001]

334.25 [< 0.001]

 Mother's age group (years)

  15–24

19.84 (13,818)

18.11 (2721)

20.31 (11,096)

  25–34

17.44 (21,453)

17.07 (6340)

17.60 (15,113)

  35–49

17.47 (2896)

17.27 (986)

17.58 (1910)

  χ²-value [p-value]

177.99 [< 0.001]

8.07 [0.018]

169.40 [< 0.001]

 Intended pregnancy

  Wanted then

18.03 (34,446)

17.08 (9094)

18.39 (25,352)

  Wanted later

21.13 (2093)

21.88 (567)

20.87 (1526)

  Wanted no more

19.78 (1628)

19.01 (386)

20.04 (1242)

  χ²-value [p-value]

74.54 [< 0.001]

43.61 [< 0.001]

37.17 [< 0.001]

 Mother's education

  No education

20.10 (7824)

20.19 (1162)

20.08 (6663)

  Primary

20.63 (5125)

22.98 (1181)

20.02 (3944)

  Secondary

18.24 (20,112)

17.46 (5246)

18.54 (14,866)

  Higher

14.50 (5104)

14.52 (2458)

14.49 (2647)

 χ²-value [p-value]

515.25 [< 0.001]

240.79 [< 0.001]

278.73 [< 0.001]

  Received full ANC

  Yes

16.09 (8590)

15.30 (3031)

16.56 (5560)

  No

18.54 (19,999)

17.93 (4852)

18.74 (15,147)

  χ²-value [p-value]

146.35 [< 0.001]

56.50 [< 0.001]

75.91 [< 0.001]

 Timing of first ANC visit

  1st trimester

17.25 (19,946)

16.27 (5832)

17.69 (14,114)

  2nd trimester

18.44 (5456)

18.28 (1237)

18.49 (4219)

  3rd trimester

18.69 (1479)

18.18 (454)

18.91 (1024)

  χ²-value [p-value]

30.53 [< 0.001]

20.83 [< 0.001]

11.51 [0.003]

 Mother's BMI (kg/m²)

  Underweight

22.00 (8467)

21.55 (1428)

22.09 (7040)

  Normal

17.75 (21,919)

17.08 (5327)

17.97 (16,593)

  Overweight & Obese

16.09 (6445)

16.34 (2741)

15.91 (3705)

  χ²-value [p-value]

508.40 [< 0.001]

94.64 [< 0.001]

391.95 [< 0.001]

 Mother's Anaemia

  Non anaemic

17.69 (14,331)

17.00 (4134)

17.99 (10,197)

  Anaemic

18.60 (22,088)

17.69 (5205)

18.90 (16,883)

  χ²-value [p-value]

26.35 [< 0.001]

4.39 [0.036]

18.80 [< 0.001]