6. Endometrial thickness: data not suitable for analysis.

Study	Intervention (number of cycles/embryo transfer)	Control (number of cycles/embryo transfer)	Endometrial thickness	P value
Loh 2001	Clomiphene‐induced ovulation (n = 67)	HT alone or HT plus GnRHa suppression (n = 37)	9.7 vs 9.8	n/s
Peeraer 2015	Natural cycle FET (n = 332)	HMG FET (n = 340)	8.9 vs 8.9	n/s

FET: frozen‐thawed embryo transfer; GnRHa: gonadotrophin releasing hormone agonist; HMG: human menopausal gonadotrophin; HT: hormone therapy; n/s: not significant.