Table 4 Main factors affecting adverse pregnancy outcomes

Infertility duration (year)

< 3

Ref

≥ 3

1.180(0.895–1.556)

BMI(kg/m²³)

< 18.5

Ref

18.5 ≤ BMI < 24

1.621(1.034–2.541)

24 ≤ BMI < 28

1.925(1.133–3.269)

≥ 28

2.026(0.940–4.366)

Female age(year)

< 30

Ref

30 ≤ Age < 35

1.028(0.748–1.411)

35 ≤ Age ≤ 37

1.361(0.869–2.131)

37< Age ≤ 40

1.649(1.025–2.653)

Male age(year)

< 30

Ref

30 ≤ Age < 35

0.747(0.512–1.090)

35 ≤ Age < 40

1.138(0.764–1.694)

≥ 40

1.204(0.722–2.009)

Infertility type

Primary infertility

Ref

Secondary infertiliy

1.021(0.771–1.351)

Transplant cycle

First cycle

Ref

Second cycle

1.148(0.851–1.549)

PCOS

No

Ref

Yes

1.200(0.859–1.676)

Endometriosis

No

Ref

Yes

0.502(0.186–1.350)

Diabetes

No

Ref

Yes

1.020(0.186–5.601)

Hypertension

No

Ref

Yes

1.020(0.253–4.108)

Thyroid disease

No

Ref

Yes

1.020(0.346–3.012)

Number of births

0

Ref

1–2

1.050(0.774–1.424)

≥ 3

2.076(0.290-14.841)

Number of miscarriages

0

Ref

1–2

1.170(0.872–1.569)

≥ 3

0.990(0.604–1.621)

Number of pregnancies

0

Ref

1–2

1.020(0.757–1.376)

≥ 3

0.968(0.635–1.475)

Number of early spontaneous abortion

0

Ref

1

1.187(0.807–1.745)

2

1.614(0.897–2.902)

Male smoking history

No

Ref

Yes

1.293(0.899–1.858)

Endometrial thickness (mm)

< 8

Ref

8–12

0.890(0.603–1.314)

> 12

1.190(0.557–2.543)