Table II.

Effectiveness of the embryo transfer strategies: pregnancy outcomes.

		Freeze all (n = 102)	Conventional (n = 102)	Relative risk	95% CI		P-value
Ongoing pregnancy (a)	Cumulative	19(19)	32 (31)	0.59	0.36	0.98	0.036*
	First ET	8 (8)	25 (25)	0.32	0.15	0.68	0.001*
	Subsequent ETs	10 (10)	5(5)	2.00	0.71	5.65	0.180
Live birth (b)	Cumulative	18 (18)	29 (28)	0.62	0.37	1.04	0.067
	First ET	7 (7)	22 (22)	0.32	0.14	0.71	0.003*
	Subsequent ETs	10 (10)	5 (5)	2.00	0.71	5.65	0.180
Clinical pregnancy	Cumulative	19 (19)	33 (33)	0.58	0.36	0.95	0.027*
	First ET	9 (9)	26 (25)	0.35	0.17	0.71	0.002*
	Subsequent ETs	10 (10)	5 (5)	2.00	0.71	5.65	0.180
Biochemical pregnancy	Cumulative	24 (24)	42 (41)	0.57	0.38	0.87	0.007*
	First ET	15 (15)	35 (34)	0.43	0.25	0.74	0.001*
	Subsequent ETs	10 (10)	9 (9)	1.11	0.47	2.62	0.810

Data presented as number (%).

In the freeze-all strategy, one woman underwent elective termination of a pregnancy at 22 weeks of gestation because of trisomy 21.

In the conventional strategy, one woman terminated the gestation because of a cervical pregnancy and two women had spontaneous miscarriages at 14 and 16 weeks of gestation.

^(a)Cumulative pregnancy rates include pregnancies without IVF.

^(b)Not all couples who achieved ongoing pregnancy ended in a live birth.

^* P-value < 0.05. ET, embryo transfer.