Table 2 Descriptive data of the study population and results of the IVF cycle according to woman’s age category

Age < 35 years

n = 8,454

n = 1,516

Age

31.04 ± 2.73

31.50 ± 2.35

<0.001

N° oocytes retrieved

11.64 ± 7.48

10.32 ± 6.56

<0.001

Cancellation rate

2.12%

2.97%

0.0066

Fertilization rate

57.51%

60.10%

0.002

Number of embryos transferred per ET

2.16 ± 0.61

2.10 ± 0.57

<0.002

Clinical pregnancy rate

27.52%

30.14%

0.040

Miscarriage rate

6.06%

5.58%

0.463

Live birth rate

27.08%

29.48%

0.058

Age 35–40 years

n = 10,379

n = 2,067

Age

37.51 ± 1.70

37.27 ± 1.65

<0.001

N° oocytes retrieved

8.39 ± 6.24

7.82 ± 5.74

<0.001

Cancellation rate

3.63%

4.64%

0.004

Fertilization rate

61.24%

60.41%

0.204

Number of embryos transferred per ET

2.27 ± 0.76

2.18 ± 0.70

<0.001

Clinical pregnancy rate

20.70%

20.02%

0.490

Miscarriage rate

5.73%

6.07%

0.555

Live birth rate

20.32%

19.64%

0.500