Table 2 Patient demographics and baseline characteristics

Age, years (mean ± SD)

31.2 ± 4.0

31.4 ± 4.1

29.3 ± 4.0

32.4 ± 4.1

<0.0001

Age categories

 ≤35 years, n (%)

1522 (85.4)

1161 (81.8)

117 (95.1)

90 (73.2)

 >35 years, n (%)

261 (14.6)

258 (18.2)

6 (4.9)

33 (26.8)

Weight (kg)

53.9 ± 7.7

55.7 ± 8.2

53.4 ± 7.8

55.6 ± 8.3

0.0168

Height (cm)

158.9 ± 5.4

159.4 ± 5.8

158.1 ± 5.0

160.2 ± 4.4

0.0003

BMI (kg/m²)

21.3 ± 2.7

21.9 ± 3.1

21.3 ± 2.7

21.7 ± 3.1

0.1876

ART treatment history

 First ART cycle, n (%)

1632 (91.5)

N/A

116 (94.3)

N/A

 Second ART cycle, n (%)

151 (8.5)

N/A

7 (5.7)

N/A

FSH level at baseline

 n (%)

1355 (76.0)

1348 (95.0)

119 (96.7)

123 (100.0)

 mean ± SD (IU/L)

5.9 ± 2.5

6.0 ± 2.1

4.5 ± 2.3

5.4 ± 2.4

0.0012

LH level at baseline

 n (%)

1407 (78.9)

1268 (89.4)

119 (96.7)

123 (100.0)

 mean ± SD (IU/L)

4.0 ± 2.8

3.9 ± 2.7

3.2 ± 2.3

3.3 ± 2.3

0.2709

AMH level at baseline

 n (%)

1382 (77.5)

393 (27.7)

123 (100.0)

123 (100.0)

 mean ± SD (ng/mL)

5.6 ± 4.4

3.8 ± 2.5

7.6 ± 3.4

3.1 ± 2.8

<0.0001

AFC at baseline

 n (%)

1525 (85.5)

1128 (79.5)

123 (100.0)

123 (100.0)

 mean ± SD

12.4 ± 7.3

10.9 ± 5.1

14.3 ± 7.8

7.9 ± 4.5

<0.0001

Down-regulation regimen, n (%)

 Available

1783 (100.0)

1419 (100.0)

105 (85.4)

123 (100)

 Missing

0 (0.0)

0 (0.0)

18 (14.6)

0 (0.0)

 GnRH agonist

1115 (62.5)

1419 (100)

98 (93.3)

123 (100.0)

 GnRH antagonist

659 (37.0)

0 (0.0)

7 ( 6.7)

 Both

5 (0.3)

0 (0.0)

 Other

4 (0.2)

0 (0.0)

Ovulation trigger

 n (%)

1747 (98.0)

1299 (91.5)

123 (100.0)

123 (100.0)

 Missing, n (%)

36 (2.0)

120 (8.5)

 hCG

··

1299 (100.0)

123 (100.0)

 rhCG

1556 (89.1)

··

115 (93.5)

 uhCG

144 (8.2)

··

 Agonist

35 (2.0)

··

7 (5.7)

 Combination^a

12 (0.7)

··

1 (0.8)

r-hLH co-administration, n (%)

333 (18.7)

366 (25.8)

40 (32.5)

26 (21.1)