Table 1 Inclusion and exclusion criteria in included studies

Kattera et al. (2003) [11]

Inclusion criteria: patients with tubal factor infertility, polycystic ovary syndrome, unexplained infertility, endometriosis; unable to conceive for at least 1 year. Exclusion criteria: very poor responders (produced < 3 follicles); men with severe oligoasthe-noteratozoospermia (density < 5 m/mL, motility < 30% and Morphology < 5%).

Dirnfeld et al. (1999) [3]

Inclusion criteria: patients with tubal factor infertility, unexplained infertility, endometriosis; aged 23–41 years; uterine morphology and endometrial line were normal assessed by hysterosalpingography and ultrasound. Exclusion criteria: very poor responders; patients with polycystic ovary syndrome; men with severe oligozoospermia.

Swenson et al. (2000) [2]

Patients were eliminated from the study for deferred transfer related to inadequate endometrial thickness, endometrial echo pattern, or risk of ovarian hyperstimulation syndrome.

Chen et al. (2019) [16]

Inclusion criteria: patients with tubal factor, endometriosis, unexplained and mild male factor; aged < 43 years. Exclusion criteria: use of donor eggs/sperm; an abnormal uterine cavity shown on hysterosalpingogram or hysteroscopy; hydrosalpinges without treatment; endometrial thickness < 8 mm on day of hCG; severe oligospermia (total number of motile sperm < 0.1 million) or normal morphology < 5%; fertilization failure or fertilization rate < 30% for conventional insemination in the past; any risk of ovarian hyperstimulation syndrome (OHSS); blastocyst transfer; and natural cycles or mild stimulation protocols (freeze all strategy).

Pongsuthirak (2019) [17]

Inclusion criteria: patients with tubal disease, endometriosis, ovulatory dysfunction, unexplained infertility; aged 20–38 years; at least 6 retrieved oocytes and normal semen parameters.

Coskun et al. (1998) [18]

Inclusion criteria: patients with tubal disease, unexplained infertility, male factor, endometriosis, polycystic ovary syndrome. Exclusion criteria: patients with no fertilization in both groups.

Boone et al. (2001) [19]

Inclusion criteria: patients with tubal factor, ovulatory dysfunction, endometriosis, pelvic factor, uterine factor; aged 23–40 years.

Gianaroli et al. (1996) [5]

Inclusion criteria: patients with tubal factor, idiopathic infertility, a male factor; aged ≤38 years; uterine morphology (assessed by hysteroscopy) and endometrial biopsies were normal.

Lundqvist et al. (2001) [20]

Inclusion criteria: patients with tubal disease, endometriosis, anovulation, a male factor, unexplained infertility; aged 25–40 years; 1–10 years of infertility. Exclusion criteria: less than 6 retrieved oocytes.

Barraud-Lang et al. (2008) [13]

Inclusion criteria: patients with tubal disease, endometriosis, dysovulation, mild male factor, and Idiopathic. Exclusion criteria: less than four retrieved oocytes; fertilization failure in both groups.

Lin et al. (2000) [15]

Couples without male infertility factors were selected for this study.