Table 1 Characteristics of the studies included in the meta-analysis.
| Author (year) | Country | Embryo stage | Country | Patients (n) | Outcomes included in the meta-analysis | |
|---|---|---|---|---|---|---|
| hCG | Control | |||||
| Mansour (2011) | Egypt | Cleavage | Egypt | 500 IU: 107 | 105/93 | Clinical pregnancy rate |
| Hong (2014) | USA | Blastocyst fresh or frozen | USA | 500 IU: 148 | 152 | Implantation rate, clinical pregnancy rate, ongoing pregnancy rate, abortion rate |
| Santibañez (2014) | Mexico | Day 3 fresh or frozen | Mexico | 500 IU: 101 | 109 | Clinical pregnancy rate |
| Zarei (2014) | Iran | Day 3 | Iran | 250 µg (equivalent to 6500 IU): 84 | 98 | Implantation rate, clinical pregnancy rate, abortion rate, ongoing pregnancy rate, ectopic pregnancy rate |
| Aaleyasin (2015) | Iran | Day 2 – 3 | Iran | 500 IU: 240 | 243 | Clinical pregnancy rate, Implantation rate, abortion rate, live birth rate |
| Wirleitner (2015) | Austria | Day 5 blastocyst | Austria | 500 IU: 599 | 587 | Implantation rate, clinical pregnancy rate, abortion rate, live birth rate |
| Dehghani (2016) | Iran | Day 2 – 3 | Iran | 500 IU: 53 1000 IU: 53 |
51 | Clinical pregnancy rate, abortion rate |
| Hossini (2016) | Iran | Cleavage or blastocyst, frozen | Iran | 500 IU: 50 | 50 | Implantation rate, clinical pregnancy rate, ongoing pregnancy rate |
| Huang (2016) | China | Day 3 frozen | China | 1000 IU: 62 | 50 | Clinical pregnancy rate, abortion rate, ongoing pregnancy rate |
| Navali (2016) | Iran | Day 3 fresh | Iran | 500 IU: 71 | 67 | Clinical pregnancy rate, ongoing pregnancy rate, abortion rate, ectopic pregnancy rate |
| Mostajeran (2017) | Iran | Blastocyst | Iran | 700 IU: 46 | 48 | Clinical pregnancy rate |
| Hafezi (2018) | India | Cleavage frozen | India | 500 IU: 60 | 60 | Clinical pregnancy live, abortion rate, live birth rate |