Table 3 Main factors affecting non- live birth outcomes

Infertility duration (year)

< 3

Ref

≥ 3

1.282(1.029–1.597)

0.027*

1.408(1.049–1.889)

0.023*

BMI(kg/m²)

< 18.5

Ref

18.5 ≤ BMI < 24

1.347(0.968–1.874)

0.077

1.235(0.882–1.730)

0.219

24 ≤ BMI < 28

1.460(0.974–2.187)

0.067

1.361(0.900-2.057)

0.144

≥ 28

1.831(1.007–3.330)

0.047*

1.773(0.967–3.252)

0.064

Female age(year)

< 30

Ref

30 ≤ Age < 35

0.992(0.771–1.276)

0.948

1.175(0.845–1.633)

0.337

35 ≤ Age ≤ 37

1.382(0.967–1.975)

0.076

1.517(0.944–2.439)

0.085

37< Age ≤ 40

1.997(1.359–2.934)

< 0.001*

2.121(1.233–3.647)

0.007*

Male age(year)

< 30

Ref

30 ≤ Age < 35

0.941(0.695–1.275)

0.696

0.909(0.649–1.273)

0.578

35 ≤ Age < 40

1.219(0.878–1.693)

0.236

0.930(0.609–1.419)

0.736

≥ 40

1.530(1.012–2.312)

0.044*

0.992(0.572–1.720)

0.977

Infertility type

Primary infertility

Ref

Secondary infertiliy

1.271(1.015–1.592)

0.037*

0.246(0.024–2.474)

0.234

Transplant cycle

First cycle

Ref

Second cycle

1.365(1.078–1.729)

0.010*

0.772(0.605–0.986)

0.038*

PCOS

No

Ref

Yes

1.029(0.783–1.352)

0.839

Endometriosis

No

Ref

Yes

0.868(0.459–1.642)

0.663

Diabetes

No

Ref

Yes

0.687(0.153–3.081)

0.624

Hypertension

No

Ref

Yes

0.917(0.294–2.858)

0.881

Thyroid disease

No

Ref

Yes

0.638(0.242–1.688)

0.366

Number of births

0

Ref

1–2

1.302(1.026–1.651)

0.030*

1.275(0.857–1.897)

0.232

≥ 3

1.497(0.249–9.001)

0.660

1.419(0.204–9.859)

0.723

Number of miscarriages

0

Ref

1–2

1.332(1.053–1.683)

0.017*

1.709(1.057–2.763)

0.029*

≥ 3

1.304(0.895–1.899)

0.167

1.530(0.655–3.573)

0.326

Number of pregnancies

0

Ref

1–2

1.192(0.937–1.517)

0.153

0.158(0.015–1.637)

0.122

≥ 3

1.436(1.040–1.983)

0.028*

0.158(0.013–1.843)

0.141

Number of early spontaneous abortion

0

Ref

1

1.106(0.810–1.509)

0.527

2

1.280(0.774–2.117)

0.337

Male smoking history

No

Ref

Yes

1.334(0.997–1.786)

0.053

Endometrial thickness (mm)

< 8

Ref

8–12

0.815(0.599–1.107)

0.191

> 12

0.916(0.486–1.726)

0.785