Table 3 Subgroup analysis of clinical features and pregnancy outcomes between Pr-AKI women living at low and high altitudes

Residential altitude (m)

2207.5 ± 345.4

3415.2 ± 244.4

-

2344.8 ± 199.7

3336.3 ± 146.9

-

Age (years)

27.6 ± 6.7

26.0 ± 4.6

0.333

27.9 ± 5.4

28.5 ± 5.0

0.686

BMI (kg/m²)

24.6 ± 2.4

24.2 ± 2.6

0.683

27.3 ± 5.2

27.3 ± 3.8

0.983

SBP (mmHg)

111.0 ± 14.9

110.6 ± 11.4

0.915

155.5 ± 18.2

153.8 ± 19.3

0.751

DBP (mmHg)

68.7 ± 10.2

69.6 ± 10.3

0.736

103.3 ± 13.6

101.5 ± 17.7

0.687

Hemoglobin (g/L)

105.4 ± 24.1

108.7 ± 38.6

0.718

125.5 ± 22.8

115.0 ± 29.9

0.187

Serum ALB (g/L)

27.4 ± 5.7

27.8 ± 4.7

0.826

25.7 ± 5.4

23.6 ± 6.0

0.212

SCr (umol/L)

91(76–109)

90(80–113)

0.872^a

88(76–97)

86(77–100)

0.592^a

Serum UA (umol/L)

429.1 ± 276.5

428.2 ± 112.5

0.989

481.4 ± 67.9

475.7 ± 91.5

0.809

Maternal death (n%)

1(3.4 %)

1(4.5 %)

1.000^b

1(4.7 %)

1(3.7 %)

0.511^b

Gestational age at delivery

(in weeks)

36.9 ± 3.4

37.0 ± 4.6

0.890

38.0 ± 1.8

36.3 ± 3.1

0.030

Delivery by cesarean section (n%)

8(30.8 %)

7(31.8 %)

0.938

10(47.6 %)

17(63.0 %)

0.288

Pre-term birth (n%)

7(26.9 %)

5(25.0 %)

0.883

5(23.8 %)

12(44.4 %)

0.138

Stillbirth/neonatal death (n%)

6(23.1 %)

4(19.0 %)

1.000^b

0

6(24.0 %)

0.029^b

Neonatal weight (g)

3018.2 ± 580.1

3030.6 ± 461.8

0.942

2963.9 ± 537.6

2625.0 ± 694.4

0.093

Apgar score at 1 min

7.6 ± 3.8

7.8 ± 3.7

0.904

8.8 ± 2.1

7.0 ± 3.8

0.091

IUGR (n%)

0

1(5.3 %)

0.442^b

3(20.0 %)

8(27.6 %)

0.480^b

Admission to NICU (n%)

2(7.7 %)

1(5.0 %)

1.000^b

5(27.8 %)

6(24.0 %)

1.000^b

LBWI (n%)

5(20.8 %)

2(10.0 %)

0.428^b

5(25.0 %)

12(48.0 %)

0.114

Renal recovery on discharge (n%)

22(91.7 %)

13(76.5 %)

0.212^b

9(64.3 %)

20(83.3 %)

0.245^b