Table 1.

Patients’ characteristics of the four different FET groups in the two study periods

Study group	1 NC-late	2 NC-early	p value between groups 1 and 2	3 AHR-late	4 AHR-early	p value between groups 3 and 4	p value between groups 2 and 4	p value between groups 1 and 3
Study period	June 2014–June 2015 natural cycle+	May 2012–May 2014 natural cycle		June 2014–June 2015 E2+	May 2012–May 2014 E2+
No. of cycles	59	74	–	54	113	–	–	–
Mean patient age at OPU (years)	32.3 ± 5.5	33.4 ± 5.0	NS	35.1 ± 4.7	32.4 + 5.3	<0.01	NS	<0.01
Etiology of infertility:
Male factor	39	46	NS	20	45	NS
Unexplained	14	18	NS	8	25	NS
Endometriosis	2	2	NS	4	3	NS
Non-ovulatory	0	0	NS	23	31	NS
Others	4	8	NS	2	11	NS

NS not significant