Correlation between different endometrial preparation protocols and pregnancy outcome of frozen embryo transfer in patients with polycystic ovary syndrome: a retrospective study

Figures & data

Table 1. Comparison of baseline data of patients.

	HRT group (n = 65)	LE group (n = 65)	GnRHa + HRT group (n = 70)	χ^2/F/t	P
Age				5.182	0.075
<28 years	25	28	40
≥28 years	40	37	30
Duration of infertility (year)	5.51 ± 2.04	5.03 ± 2.02	4.80 ± 2.33	1.907	0.151
Type of infertility				0.071	0.965
Primary	50	50	55
Secondary	15	15	15
Body mass index	22.42 ± 1.22	22.24 ± 1.30	22.54 ± 1.15	1.039	0.356
Quality of frozen embryos transferred				0.897	0.639
All high-quality embryos	58	59	60
Mix of high- and low-quality embryos	7	6	10
Basal LH (IU/L)	9.21 ± 2.03	8.98 ± 2.23	9.26 ± 2.28	0.302	0.740
Basal FSH (IU/L)	6.29 ± 1.13	5.90 ± 1.07	5.96 ± 1.25	2.189	0.115
Basal E2 (pg/mL)	45.30 ± 10.00	45.54 ± 8.98	47.30 ± 9.89	0.874	0.419

Measurement data were expressed as mean ± standard deviation, and enumeration data were expressed as number of cases. LH, luteinizing hormone; FSH, follicle-stimulating hormone; E2, estradiol. HRT, hormone replacement treatment; LE, ovulation induction using letrozole; GnRHa + HRT, gonadotropin-releasing hormone agonist for pituitary down-regulation combined with HRT.

Table 2. Comparison of endometrial thickness on the day of endometrial transformation, number of embryos transferred and number of high-quality embryos transferred among the three groups.

	HRT group (n = 65)	LE group (n = 65)	GnRHa + HRT group (n = 70)	χ^2/t	P
Endometrial thickness on the day of endometrial transformation (cm)	0.89 ± 0.09	0.88 ± 0.12	0.93 ± 0.11	4.273	0.015
Number of embryos transferred (n)	1.95 ± 0.78	1.84 ± 0.69	2.10 ± 0.84	1.840	0.162
Number of high-quality embryos transferred (n)	1.04 ± 0.21	1.03 ± 0.17	1.04 ± 0.20	0.110	0.896

Measurement data were presented as mean ± standard deviation (SD). HRT, hormone replacement treatment; LE, ovulation induction using letrozole; GnRHa + HRT, gonadotropin-releasing hormone agonist for pituitary down-regulation combined with HRT.

Table 3. Comparison of pregnancy outcomes of three endometrial preparation protocols.

	HRT group (n = 65)	LE group (n = 65)	GnRHa + HRT group (n = 70)	χ^2	P
Clinical pregnancy rate (%)	38.50 (25)	41.50 (27)	67.10 (47)	13.533	0.001
Live birth rate (%)	30.77 (20)	33.85 (22)	60.00 (42)	14.450	0.001
Embryo implantation rate (%)	76.92 (50)	78.46 (51)	84.29 (59)	1.284	0.526
Biochemical pregnancy rate (%)	3.08 (2)	3.08 (2)	4.29 (3)	0.070	0.966
Ectopic pregnancy rate (%)	3.08 (2)	1.54 (1)	2.86 (2)	0.339	0.844
Abortion rate (%)	15.38 (10)	15.38 (10)	17.14 (12)	0.105	0.949

Enumeration data were presented as n (%). HRT, hormone replacement treatment; LE, ovulation induction using letrozole; GnRHa + HRT, gonadotropin-releasing hormone agonist for pituitary down-regulation combined with HRT.

Table 4. Factors influencing clinical pregnancy in frozen embryo transfer.

	Successful pregnancy group (n = 99)	Failed pregnancy group (n = 101)	χ^2/t	P
Age			72.193	<0.001
<28 years	76	17
≥28 years	23	84
Endometrial preparation protocol			13.533	<0.001
HRT	25	40
LE	27	38
GnRHa + HRT	47	23
Number of embryos transferred (n)	2.23 ± 0.71	1.71 ± 0.75	5.012	<0.001
Endometrial thickness(cm)	0.95 ± 0.10	0.84 ± 0.08	8.464	<0.001
Duration of infertility (year)	3.48 ± 1.05	6.70 ± 1.69	−16.145	<0.001
Basal LH (IU/L)	9.40 ± 2.22	8.91 ± 2.12	1.618	0.107
Basal FSH (IU/L)	6.06 ± 1.17	6.04 ± 1.16	0.104	0.917
Basal E2 (pg/mL)	44.93 ± 9.69	47.20 ± 9.50	−1.655	0.098
Type of infertility			0.852	0.356
Primary	74	81
Secondary	25	20

Measurement data were expressed as mean ± standard deviation, and enumeration data were expressed as number of cases. HRT, hormone replacement treatment; LE, ovulation induction using letrozole; GnRHa + HRT, gonadotropin-releasing hormone agonist for pituitary down-regulation combined with HRT; LH, luteinizing hormone; FSH, follicle-stimulating hormone; E2, estradiol.

Table 5. Multivariate analysis of frozen embryo transfer clinical pregnancy in PCOS patients.

Variables	B	S.E,	Wals	P	OR	95%CI
Age	−2.045	0.646	10.030	0.002	0.129	0.036–0.459
Number of embryos transferred	1.305	0.466	7.829	0.005	3.686	1.478–9.192
Duration of infertility	−1.753	0.346	25.621	<0.001	0.173	0.088–0.342
Endometrial thickness	1.302	0.376	11.993	0.001	3.676	1.760–7.680
Endometrial preparation protocols			8.533	0.014
HRT (A reference)
LE	−1.182	0.753	2.466	0.116	0.307	0.070–1.341
GnRHa + HRT	1.746	0.916	3.635	0.047	5.731	0.952–34.498

HRT, hormone replacement treatment; LE, ovulation induction using letrozole; GnRHa + HRT, gonadotropin-releasing hormone agonist for pituitary down-regulation combined with HRT.