Table 1 Characteristics of inculded studies

Haas et al. (2020) [14]

None

Yes

Morning of the trigger day

2016–2018

Age 18–41 y; BMI 18–35 kg/m2; AMH > 1 ng/ml; AFC 6–20; FSH < 20 IU/l; first three IVF cycle

E2 levels > 15,000 pmol/l; moderate–severe endometriosis

146

hCG 10,000 IU and GnRH agonist 0.5 mg

hCG 10,000 IU and placebo

Mahajan et al. (2016) [21]

None

Yes

NR

NR

Aged 24–43; AMH < 4 ng/ml; AFCs/ovary < 12

None

76

hCG 5000 IU and GnRH agonist 1 mg

hCG 10,000 IU

Ali et al. (2020) [13]

None

Yes

NR

2016–2018

First ICSI cycle; aged less than 40 y; BMI 18–30 kg/m2; AMH > 1 ng/ml; normal, mild or moderate male factor infertility

Azoospermic males

160

250 IU of recombinant HCG and GnRH agonist 1 mg

250 IU of recombinant HCG

Schachter et al. (2008) [24]

NR

Yes

Onset of intervention

NR

Failed at least one IVF-ET cycle on GnRH agonist long protocol; hysterosalpingogram or hysteroscopy history; BMI 18–30 kg/m2;

Lack of oocytes aspirated in previous cycles;

211

hCG 5000 IU and GnRH agonist 0.2 mg

hCG 5000 IU

Haas et al. (2019) [19]

None

Yes

NR

2015–2017

Poor responders defined with the Bologna criteria.

None

23

hCG 6500 IU and GnRH agonist (dose not reported)

hCG 6.500 IU

Eftekhar et al. (2017) [20]

None

Yes

Leading follicles reached 17 mm in diameter

2014–2015

Aged less than 42 y; BMI 18–30 kg/m2; moderate ovarian response

Endocrine disorders; PCOS; UA; RIF; azoospermia; day-3 FSH ≥ 10 IU/L or AMH ≤1.0 ng/mL

192

hCG 6500 IU and GnRH agonist 0.2 mg

hCG 6.500 IU

Kim et al. (2014) [22]

NR

Yes

NR

NR

Women with regular ovulatory cycles

PCOS, metabolic disorders

120

250 μg rhCG and GnRH agonist 0.1 mg

250 μg rhCG and placebo

Decleer et al. (2014) [23]

NR

Yes

NR

2011–2013

Tubal or male infertility, BMI < 32, age ≤ 38 y, frst, second and third IVF cycle.

Azospermia, UA, PCOS, endocrine disorders, endometriosis

120

hCG 5000 IU and GnRH agonist 0.2 mg

hCG 5000 IU