Table 2 Comparison of patient characteristics and stimulation protocols between the low and normal ORR groups

Age (y)

29.00 (27.00–32.00)

29.00 (27.00–32.00)

0.236

BMI (kg/m²)

23.48 (20.40–26.50)

22.89 (20.58–25.71)

0.140

Infertility years (y)

3.00 (2.00–5.00)

3.00 (2.00–5.00)

0.601

Infertility factors

Primary infertility

231 (56.90)

1058 (51.14)

0.034

Tubal factor

209 (51.48)

1076 (52.01)

0.846

Endometriosis

11 (2.71)

36 (1.74)

0.191

History of ovarian surgery

4 (0.99)

13 (0.63)

0.505

Basal testosterone (ng/mL)

2.04 (1.52–2.34)

2.02 (1.53–2.21)

0.120

AMH (ng/mL)

6.55 (5.42–8.76)

6.50 (5.27–8.66)

0.285

Antral follicle count

30.00 (26.00–37.00)

30.00 (26.00–36.00)

0.193

Duration of stimulation (d)

12.00 (10.00–15.00)

11.00 (10.00–13.00)

< 0.001

Stimulation protocol

Agonist downregulation

209 (51.48)

1046 (50.56)

Antagonist

74 (18.23)

657 (31.75)

MPA

123 (30.30)

366 (17.69)

< 0.001*

Trigger type

recombinant -hCG

295 (72.66)

1355 (65.49)

GnRH-a

90 (22.17)

529 (25.57)

GnRH-a + hCG

21 (5.17)

185 (8.94)

0.007 *

Hormones levels on the trigger day

E2 (pg/mL)

3748.43 (2408.09-5250.37)

3937.33 (2646.87-5523.43)

0.059

LH (mIU/mL)

1.57 (1.03–2.36)

1.84 (1.21–2.89)

< 0.001

P (ng/mL)

0.70 (0.48–1.04)

0.99 (0.67–1.37)

< 0.001

E2/follicle (pg/mL)

146.27 (103.36-186.75)

199.61 (151.38-253.25)

< 0.001

Interval between trigger and aspiration (h)

36.00 (36.00–37.00)

36.00 (36.00–37.00)

0.593

No. of follicles ≥ 12 mm

25.00 (19.00–35.00)

20.00 (15.00–26.00)

< 0.001

No. of retrieved oocytes

8.00 (5.00–12.00)

17.00 (13.00–23.00)

< 0.001

No. of high-quality embryos

2.00 (1.00–4.00)

5.00 (3.00–8.00)

< 0.001

Cycles with no available embryos

22 (5.42)

9 (0.43)

< 0.001

Clinical pregnancy per fresh embryo transfer

115/203 (56.65)

436/701 (62.20)

0.154

Severe OHSS

7 (1.72)

28 (1.35)

0.563