Table 3 Factors affecting the formation of high quality blastocysts

Infertility duration (year)

< 3

Ref

≥ 3

0.949(0.627–1.436)

0.804

BMI(kg/m²)

< 24

Ref

≥ 24

0.762(0.485–1.198)

0.239

Female age(year)

< 35

Ref

35 ≤ age ≤ 42

0.683(0.436–1.068)

0.095

Male age(year)

< 35

Ref

≥ 35

0.534(0.351–0.812)

0.003^*

0.723(0.447–1.169)

0.186

Infertility type

Primary infertility

Ref

Secondary infertiliy

1.082(0.709–1.65)

0.716

OPU cycle

First cycle

Ref

Second cycle

0.511(0.271–0.964)

0.038^*

0.575(0.284–1.163)

0.124

Third cycle

0.437(0.140–1.367)

0.155

0.488(0.133–1.796)

0.281

Fourth cycle

0.349(0.063–1.938)

0.229

0.733(0.124–4.340)

0.732

AMH(ng/ml)

< 2

Ref

2–5

1.952(1.222–3.117)

0.005^*

1.104(0.593–2.056)

0.755

> 5

3.148(1.672–5.927)

< 0.001^*

1.543(0.660–3.608)

0.317

No. of oocytes retrieved

< 10

Ref

10–14

3.444(2.013–5.893)

< 0.001^*

3.345(1.832–6.107)

< 0.001^*

≥ 15

5.437(3.182–9.290)

< 0.001^*

3.820(1.925–7.581)

< 0.001^*

Duration of Gn treatment(day)

< 10

Ref

10–14

1.463(0.812–2.637)

0.206

≥ 15

0.765(0.319–1.837)

0.549

Gn dosage(IU)

< 1500

Ref

1500–3000

0.984(0.506–1.912)

0.961

1.382(0.634–3.014)

0.416

> 3000

0.430(0.211–0.875)

0.020^*

0.755(0.312–1.823)

0.531

Fertilization method

IVF

Ref

ICSI

0.995(0.592–1.673)

0.986

PCOS

No

Ref

Yes

1.035(0.530–2.023)

0.919

Endometriosis

No

Ref

Yes

1.488(0.538–4.114)

0.444

DOR

No

Ref

Yes

0.323(0.168–0.621)

0.001^*

1.178(0.496–2.794)

0.711

COVID-19 infection at the time of OPU

No

Ref

Yes

0.889(0.471–1.676)

0.716

1.255(0.611–2.578)

0.537

Recovery

0.613(0.387–0.971)

0.037^*

0.599(0.360–0.996)

0.048^*

Male factor

No

Ref

Yes

0.699(0.428–1.140)

0.151

Trigger day E2(pg/ml)

< 2500

Ref

2500 ≤ E2 < 4000

2.123(1.278–3.526)

0.004^*

1.016(0.546–1.889)

0.960

≥ 4000

2.972(1.382–6.393)

0.005^*

1.089(0.447–2.655)

0.852

Trigger day P(ng/ml)

< 1.5

Ref

≥ 1.5

2.743(0.742–10.139)

0.130