Table 2 Demographic and clinical details of mothers and children for the full sample and stratified by tertiles of fetal renal volume

n

630

447

433

210

210

210

Mother’s details

Mother’s ethnic group

White

271 (43.0)

190 (42.5)

185 (42.7)

54 (25.7)

90 (42.9)

127 (60.5)

South Asian

332 (52.7)

240 (53.7)

228 (52.7)

150 (71.4)

109 (51.9)

73 (34.8)

Other

27 (4.3)

17 (3.8)

20 (4.6)

6 (2.9)

11 (5.2)

10 (4.8)

Educational attainment

None (< 5 GCSE or equivalent)

122 (19.4)

82 (18.3)

78 (18.0)

51 (24.3)

36 (17.1)

35 (16.7)

School (≥ 5 GCSE or equivalent)

182 (28.9)

137 (30.7)

123 (28.4)

62 (29.5)

54 (25.7)

66 (31.4)

Further (A level) and higher

281 (44.6)

197 (44.1)

204 (47.1)

86 (41.0)

106 (50.5)

89 (42.4)

Others (other, overseas, unknown)

45 (7.1)

31 (6.9)

28 (6.5)

11 (5.2)

14 (6.7)

20 (9.5)

Marital status

Married

479 (76.0)

339 (75.8)

334 (77.1)

177 (84.3)

164 (78.1)

138 (65.7)

Single (never married, divorced or separated)

151 (24.0)

108 (24.2)

99 (22.9)

33 (15.7)

46 (21.9)

72 (34.3)

Housing tenure

Buying/own

420 (66.7)

294 (65.8)

296 (68.4)

148 (70.5)

146 (69.5)

126 (60.0)

Renting or other related

210 (33.3)

153 (34.2)

137 (31.6)

62 (29.5)

64 (30.5)

84 (40.0)

Employment status during pregnancy

Employed

313 (49.7)

211 (47.2)

220 (50.8)

85 (40.5)

110 (52.4)

118 (56.2)

Previously employed

167 (26.5)

135 (30.2)

102 (23.6)

56 (26.7)

54 (25.7)

57 (27.1)

Never employed

150 (23.8)

101 (22.6)

111 (25.6)

69 (32.9)

46 (21.9)

35 (16.7)

Age at antenatal booking, years

28.2 ± 5.6

28.0 ± 5.6

28.6 ± 5.6

27.6 ± 5.2

28.4 ± 5.6

28.7 ± 5.9

% missing

0.5

0.4

0.5

0.5

0.5

0.5

BMI at antenatal booking, kg/m²

26.7 ± 5.9

26.6 ± 5.7

26.8 ± 6.1

25.3 ± 5.1

27.0 ± 5.8

27.8 ± 6.3

% missing

2.5

2.9

2.5

2.4

3.3

1.9

Height at antenatal booking, cm

161.7 ± 6.3

161.5 ± 6.3

162.0 ± 6.3

160.2 ± 6.2

161.7 ± 6.0

163.1 ± 6.4

% missing

0.6

0.9

0.2

0.5

1.0

0.5

Parity

0

243 (39.5)

166 (38.2)

167 (39.7)

73 (36.0)

86 (41.8)

84 (40.8)

1

177 (28.8)

131 (30.1)

117 (27.8)

53 (26.1)

60 (29.1)

64 (31.1)

2

103 (16.8)

73 (16.8)

70 (16.6)

41 (20.2)

36 (17.5)

26 (12.6)

3+

92 (15.0)

65 (15.0)

67 (15.9)

36 (18.2)

24 (12.6)

32 (15.6)

% missing

2.4

2.7

2.8

3.3

1.9

1.9

Mother smoked during pregnancy

No

556 (88.3)

387 (86.6)

391 (90.3)

192 (91.4)

185 (88.1)

179 (85.2)

Yes

74 (11.8)

60 (13.4)

42 (9.7)

18 (8.6)

25 (11.9)

31 (14.8)

Mother drank alcohol during pregnancy

No

549 (87.1)

389 (87.0)

375 (86.6)

196 (93.3)

178 (84.8)

175 (83.3)

Yes

81 (12.9)

58 (13.0)

58 (13.4)

14 (6.7)

32 (15.2)

35 (16.7)

Gestational diabetes

No

581 (92.5)

418 (93.7)

396 (91.9)

196 (93.3)

197 (93.3)

190 (90.9)

Yes

47 (7.5)

28 (6.3)

35 (8.1)

14 (6.7)

14 (6.7)

19 (9.1)

% missing

0.3

0.2

0.5

-

0.5

0.5

Renal measures (scan)

Volume, cm³

9.67 ± 2.83

9.62 ± 2.82

9.65 ± 2.86

6.91 ± 0.90

9.29 ± 0.61

12.80 ± 2.29

Volume/estimated fetal weight, cm³/kg

4.32 ± 1.13

4.31 ± 1.16

4.30 ± 1.11

3.26 ± 0.49

4.22 ± 0.48

5.47 ± 0.94

Volume/birth weight, cm³/kg

2.92 ± 0.78

2.91 ± 0.78

2.91 ± 0.76

2.24 ± 0.39

2.87 ± 0.40

3.66 ± 0.72

Child’s

Gender

Male

331 (52.5)

224 (50.1)

234 (54.0)

97 (46.2)

100 (47.6)

134 (63.8)

Female

299 (47.5)

223 (49.9)

199 (46.0)

113 (53.8)

110 (52.4)

76 (36.2)

Gestational age at birth, weeks

39.8 ± 1.1

39.9 ± 1.1

39.8 ± 1.1

39.7 ± 1.1

39.8 ± 1.2

39.9 ± 1.2

Birth weight, g

3323 ± 483

3320 ± 464

3330 ± 492

3131 ± 421

3291 ± 454

3547 ± 479

Blood pressure

Systolic

111 ± 12

112 ± 12

111 ± 12

112 ± 11

111 ± 12

111 ± 12

Diastolic

70 ± 10

70 ± 9

70 ± 9

70 ± 9

71 ± 10

69 ± 9

% missing

4.3

2.9

5.5

5.7

1.9

5.2

Age at renal measurement, years

8.8 ± 0.9

8.9 ± 0.9

8.8 ± 0.9

8.9 ± 0.9

8.8 ± 0.9

8.8 ± 0.8

% missing

0.3

-

0.5

-

0.5

0.5

Cystatin C, mg/L

N

426

426

239

147

141

138

Mean ± SD

0.83 ± 0.08

0.83 ± 0.08

0.83 ± 0.08

0.85 ± 0.08

0.83 ± 0.08

0.82 ± 0.08

Estimated Glomerular Filtration Rate (eGFR) (Schwartz creatinine only)*

n

380

380

211

128

125

127

Mean ± SD

116.8 ± 17.3

116.8 ± 17.3

117.4 ± 16.9

114.5 ± 17.1

117.4 ± 16.8

118.4 ± 17.7

< 60

-

-

-

-

-

-

eGFR (Schwartz combined formula)*

n

361

361

201

124

118

119

Mean ± SD

91.8 ± 8.8

91.8 ± 8.8

92.3 ± 8.9

89.8 ± 8.7

92.1 ± 8.0

93.7 ± 9.3

< 60

-

-

-

-

-

-

eGFR (Zappitelli CystatinC)**

n

426

426

239

147

141

138

Mean ± SD

95.2 ± 10.3

95.2 ± 10.3

95.5 ± 10.4

93.1 ± 10.3

96.1 ± 10.1

96.6 ± 10.3

< 60

-

-

-

-

-

-

eGFR (Filler CystatinC)***

n

426

426

239

147

141

138

Mean ± SD

153.5 ± 36.5

153.5 ± 36.5

154.3 ± 36.9

146.2 ± 36.0

156.3 ± 35.5

158.5 ± 37.1

< 60

1 (0.2)

1 (0.2)

-

-

1 (0.5)

-

Albumin creatinine ratio (ACR)

N

416

238

416

150

127

139

Mean ± SD

0.7 ± 2.5

0.8 ± 3.2

0.7 ± 2.5

0.6 ± 1.0

0.6 ± 0.7

1.0 ± 4.2

< 2.5 (M)/<3.5 (F)

405 (97.4)

229 (96.2)

202 (97.4)

146 (97.3)

126 (99.2)

133 (95.7)

≥ 2.5 (M)/ ≥3.5 (F)

11 (2.6)

9 (3.8)

11 (2.6)

4 (2.7)

1 (0.8)

6 (4.3)

Protein creatinine ratio (PCR)

n

392

225

392

142

117

133

Mean ± SD

10.5 ± 4.8

10.7 ± 5.8

10.5 ± 4.8

10.4 ± 3.4

10.6 ± 2.8

10.5 ± 7.1

< 15

362 (92.4)

207 (92.0)

362 (92.4)

130 (91.6)

108 (92.3)

124 (93.2)

≥ 15

30 (7.7)

18 (8.0)

30 (7.7)

12 (8.5)

9 (7.7)

9 (6.8)

Urinary retinol binding protein (RBP) (mg/L)

< 2

429 (99.1)

247 (98.8)

429 (99.1)

155 (100)

127 (97.0)

147 (100)

3

1 (0.2)

1 (0.4)

1 (0.2)

-

1 (0.8)

-

Missing/No result

3 (0.7)

2 (0.8)

3 (0.7)

-

3 (2.3)

-