Table 1 Demographics and characteristics of pregnant women who conceived by IVF, 2018–2023.

From: The effect of air pollution exposure on foetal growth restriction in pregnant women who conceived by in vitro fertilisation a cross-sectional study

Characteristic

Before PSM matching

After PSM matching

Contrl group (n = 1399)

FGR group (n = 30)

p-value

Contrl group (n = 60)

FGR group (n = 30)

p-value

Age, n (%)

  

0.849

  

1.000

 < 35 years

817 (58.40%)

17 (56.67%)

 

34 (56.67%)

17 (56.67%)

 

 ≥ 35 years

582 (41.60%)

13 (43.33%)

 

26 (43.33%)

13 (43.33%)

 

Occupation, n (%)

  

0.960

  

0.878

 Employeda

833 (59.54%)

18 (60.00%)

 

37 (61.67%)

18 (60.00%)

 

 Otherb

566 (40.46%)

12 (40.00%)

 

23 (38.33%)

12 (40.00%)

 

Ethnicity, n (%)

  

0.108

  

1.000

 Han

1,368 (97.78%)

28 (93.33%)

 

56 (93.33%)

28 (93.33%)

 

 Otherc

31 (2.22%)

2 (6.67%)

 

4 (6.67%)

2 (6.67%)

 

Pregnancy type, n (%)

  

0.352

  

1.000

 Nonprimiparous

995 (71.12%)

19 (63.33%)

 

38 (63.33%)

19 (63.33%)

 

 Primiparous

404 (28.88%)

11 (36.67%)

 

22 (36.67%)

11 (36.67%)

 

Embryo Type, n (%)

  

0.789

  

1.000

 Cleavage-stage embryo

947 (67.69%)

21 (70.00%)

 

42 (70.00%)

21 (70.00%)

 

 Blastocyst

452 (32.31%)

9 (30.00%)

 

18 (30.00%)

9 (30.00%)

 

Anemic, n (%)

  

0.131

  

1.000

 No

786 (56.18%)

21 (70.00%)

 

42 (70.00%)

21 (70.00%)

 

 Yes

613 (43.82%)

9 (30.00%)

 

18 (30.00%)

9 (30.00%)

 

Blood type, n (%)

  

0.519

  

0.714

 Type A

404 (28.88%)

6 (20.00%)

 

19 (31.67%)

6 (20.00%)

 

 Type B

347 (24.80%)

6 (20.00%)

 

10 (16.67%)

6 (20.00%)

 

 Type O

543 (38.81%)

15 (50.00%)

 

26 (43.33%)

15 (50.00%)

 

 Type AB

105 (7.51%)

3 (10.00%)

 

5 (8.33%)

3 (10.00%)

 

Infant gender, n (%)

  

0.218

  

1.000

 Male

810 (57.90%)

14 (46.67%)

 

28 (46.67%)

14 (46.67%)

 

 Female

589 (42.10%)

16 (53.33%)

 

32 (53.33%)

16 (53.33%)

 

Eclampsia, n (%)

  

< 0.001

  

0.001

 No

1,305 (93.28%)

20 (66.67%)

 

56 (93.33%)

20 (66.67%)

 

 Yes

94 (6.72%)

10 (33.33%)

 

4 (6.67%)

10 (33.33%)

 

Uterine scar, n (%)

  

0.596

  

0.488

 No

1,170 (83.63%)

24 (80.00%)

 

44 (73.33%)

24 (80.00%)

 

 Yes

229 (16.37%)

6 (20.00%)

 

16 (26.67%)

6 (20.00%)

 

Gestational diabetes mellitus, n (%)

  

0.033

  

0.143

 No

1,073 (76.70%)

18 (60.00%)

 

45 (75.00%)

18 (60.00%)

 

 Yes

326 (23.30%)

12 (40.00%)

 

15 (25.00%)

12 (40.00%)

 

Hypertension in pregnancy, n (%)

  

< 0.001

  

0.067

 No

1,354 (96.78%)

25 (83.33%)

 

57 (95.00%)

25 (83.33%)

 

 Yes

45 (3.22%)

5 (16.67%)

 

3 (5.00%)

5 (16.67%)

 

Thyroid disease in pregnancy, n (%)

  

0.265

  

0.469

 No

1,356 (96.93%)

28 (93.33%)

 

58 (96.67%)

28 (93.33%)

 

 Yes

43 (3.07%)

2 (6.67%)

 

2 (3.33%)

2 (6.67%)

 

Air pollution, mean (SD)

      

 PM2.5, µg/m3

25.35 (3.65)

26.05 (3.85)

0.287

25.93 (3.65)

26.05 (3.85)

0.871

 PM10, µg/m3

45.86 (5.69)

45.96 (5.96)

0.943

45.90 (5.26)

45.96 (5.96)

0.963

 NO2, µg/m3

36.27 (5.09)

37.82 (5.02)

0.108

37.13 (5.00)

37.83 (5.02)

0.638

 O3, µg/m3

55.99 (6.77)

50.60 (7.52)

< 0.001

54.60 (6.15)

50.60 (7.52)

0.008

 SO2, µg/m3

6.68 (0.81)

6.57 (0.75)

0.458

6.86 (1.01)

6.57 (0.75)

0.281

  1. IVF in vitro fertilization, FGR Foetal growth restriction, PM2.5 particulate matter with aerodynamic diameter of ≤ 2.5 μm, PM10 particles matter with an aerodynamic equivalent diameter ≤ 10 μm, NO2 nitrogen dioxide, O3 ozone, SO2 sulphur dioxide.
  2. aCivil servants, employees of enterprises and institutions.
  3. bSelf-employed, freelancer, farmers, unemployed individuals, students, etc.
  4. cBuyi, Korean, Dong, etc.
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