No Effect of Inactivated SARS-CoV-2 Vaccination on in vitro Fertilization Outcomes: A Propensity Score-Matched Study

Figures & data

Figure 1 The flowchart of the study.

Abbreviation: PGT, preimplantation genetic testing.

Table 1 Baseline Characteristics Grouped by the Vaccination Status

	Before PSM		P-value	After PSM		P-value
	Vaccinated (n = 150)	Unvaccinated (n = 2035)		Vaccinated (n = 146)	Unvaccinated (n = 584)
Age (years)	33.7±5.6	31.8±5.1	<0.001	33.6±5.5	33.4±5.5	0.781
Body mass index (kg/m^2)	22.1±3.1	22.3±3.1	0.582	22.1±3.1	22.3±3.0	0.493
Infertility duration (years)	4.3±3.0	4.3±3.2	0.949	4.4±2.9	4.3±3.3	0.786
Type of infertility, n (%)			0.084			0.968
Primary	45 (30.0)	754 (37.1)		45 (30.8)	179 (30.7)
Secondary	105 (70.0)	1281 (62.9)		101 (69.2)	405 (69.3)
Infertility diseases
Tubal factor, n (%)	88 (58.7)	1370 (67.3)	0.030	87 (59.6)	342 (58.6)	0.822
Male factor, n (%)	37 (24.7)	472 (23.2)	0.681	36 (24.7)	149 (25.5)	0.832
Ovulatory dysfunction, n (%)	22 (14.7)	280 (13.8)	0.756	21 (14.4)	88 (15.1)	0.836
Endometriosis, n (%)	15 (10.0)	142 (7.0)	0.167	14 (9.6)	54 (9.2)	0.899
Intrauterine adhesion, n (%)	22 (14.7)	223 (11.0)	0.165	21 (14.4)	85 (14.6)	0.958
Unexplained, n (%)	0 (0)	8 (0.4)	1.000	0 (0)	0 (0)	1.000
Antral follicle count	11.7±7.0	12.8±6.6	0.071	11.7±6.8	11.9±6.9	0.764
Previous IVF attempts, n (%)			0.069			0.804
0	112 (74.7)	1511 (74.3)		109 (74.7)	421 (72.1)
1–2	32 (21.3)	345 (17.0)		31 (21.2)	134 (23.0)
≥3	6 (4.0)	179 (8.8)		6 (4.1)	29 (5.0)
Ovarian stimulation protocol, n (%)			<0.001			0.854
GnRH agonist	86 (57.3)	1550 (76.2)		86 (58.9)	329 (56.3)
GnRH antagonist	33 (22.0)	197 (9.7)		30 (20.5)	128 (21.9)
Others	31 (20.7)	288 (14.2)		30 (20.5)	127 (21.7)
Fertilization method, n (%)*			0.095			0.826
IVF	100 (67.1)	1348 (67.1)		100 (69.0)	386 (66.8)
ICSI	46 (30.9)	539 (26.8)		42 (29.0)	176 (30.4)
IVF+ICSI	3 (2.0)	121 (6.0)		3 (2.1)	16 (2.8)

Notes: Data are presented as mean ± standard deviation or number (percentage). *One vaccinated woman and 27 unvaccinated women had no available oocytes for fertilization.

Abbreviations: PSM, propensity score matching; IVF, in vitro fertilization; ICSI, intracytoplasmic sperm injection; GnRH, gonadotropin-releasing hormone.

Figure 2 Propensity score histograms of vaccinated and unvaccinated women before and after matching. The propensity scores were successfully balanced between the two groups after matching.

Table 2 Cycle Characteristics and Laboratory Outcomes Grouped by the Vaccination Status

	Before PSM		P-value	After PSM		P-value
	Vaccinated (n = 150)	Unvaccinated (n = 2035)		Vaccinated (n = 146)	Unvaccinated (n = 584)
Stimulation duration (days)	10.2±2.3	10.4±2.7	0.452	10.3±2.3	9.9±2.8	0.084
Total gonadotropin dose (IU)	2012.3±722.7	2011.9±829.3	0.995	2019.6±721.2	1969.1±812.4	0.493
LH level on trigger day (mIU/mL)	2.4±1.6	2.3±3.1	0.390	2.4±1.6	2.7±3.9	0.234
E2 level on trigger day (pg/mL)	1764.5±1513.0	1920.1±1483.2	0.220	1770.2±1525.3	1698.1±1344.6	0.606
P level on trigger day (ng/mL)	0.3±0.3	0.4±0.4	0.226	0.3±0.3	0.3±0.3	0.873
EMT on trigger day (mm)	9.9±3.1	10.4±2.8	0.068	10.0±3.1	10.1±2.9	0.761
No. of ≥14 mm follicles on trigger day	7.4±4.4	8.2±4.3	0.019	7.4±4.4	7.6±4.4	0.730
No. of oocytes retrieved	9.9±7.2	11.1±6.9	0.049	9.9±7.1	9.9±6.7	0.893
No. of MII oocytes	8.2±6.1	8.8±5.7	0.238	8.3±6.1	7.9±5.6	0.536
No. of 2PN oocytes	6.3±4.9	6.8±4.7	0.253	6.4±4.9	6.2±4.7	0.746
No. of cleaved embryos	6.1±4.8	6.5±4.6	0.335	6.2±4.8	6.0±4.5	0.686
No. of good-quality embryos on day 3	1.9±2.1	1.8±2.0	0.434	2.0±2.2	1.7±2.0	0.144
Oocyte retrieval rate (%)	132.8±43.9	136.2±53.5	0.362	132.0±43.8	132.6±54.1	0.888
Mature oocyte rate (%)	83.2±17.6	81.4±28.5	0.264	83.6±17.5	82.4±19.3	0.503
Normal fertilization rate (%)	71.2±23.5	67.5±23.3	0.064	71.1±23.3	70.2±23.9	0.681
Cleavage rate (%)	97.8±6.3	96.2±10.7	0.005	97.9±6.2	96.7±11.1	0.088
Good-quality embryo rate (%)	34.0±30.6	28.6±27.0	0.039	33.5±29.8	29.9±28.6	0.184
Blastocyst formation rate (%)	74.5±30.6	71.2±32.1	0.308	74.5±30.5	71.6±31.3	0.407
Available blastocyst rate (%)	71.8±28.6	72±30.0	0.942	72.2±27.9	71.3±30.2	0.803

Note: Data are presented as mean ± standard deviation.

Abbreviations: PSM, propensity score matching; LH, luteinizing hormone; E₂, estradiol; P, progesterone; EMT, endometrial thickness; MII, metaphase II; 2PN, two pronuclei.

Table 3 Pregnancy Outcomes Grouped by the Vaccination Status

	Before PSM		P-value	After PSM		P-value
	Vaccinated (n = 66)	Unvaccinated (n = 1103)		Vaccinated (n = 66)	Unvaccinated (n = 236)
No. of embryos transferred, n (%)			0.126			0.093
Single	24 (36.4)	305 (27.7)		24 (36.4)	61 (25.8)
Double	42 (63.6)	798 (72.3)		42 (63.6)	175 (74.2)
Embryo stage at transfer, n (%)			0.241			0.141
Cleavage	46 (69.7)	839 (76.1)		46 (69.7)	185 (78.4)
Blastocyst	20 (30.3)	264 (23.9)		20 (30.3)	51 (21.6)
Embryo transfer strategy, n (%)			0.101			0.060
Double cleavage	40 (60.6)	787 (71.4)		40 (60.6)	174 (73.7)
Single blastocyst	18 (27.3)	253 (22.9)		18 (27.3)	50 (21.2)
Single cleavage	6 (9.1)	52 (4.7)		6 (9.1)	11 (4.7)
Double blastocyst	2 (3.0)	11 (1.0)		2 (3.0)	1 (0.4)
Biochemical pregnancy rate, n/N (%)	43/66 (65.2)	822/1103 (74.5)	0.092	43/66 (65.2)	174 (73.7)	0.171
Clinical pregnancy rate, n/N (%)	39/66 (59.1)	712/1103 (64.6)	0.369	39/66 (59.1)	150 (63.6)	0.507
Implantation rate, n/N (%)	49/108 (45.4)	922/1901 (48.5)	0.527	49/108 (45.4)	192/411 (46.7)	0.803

Note: Data are presented as number (percentage).

Abbreviation: PSM, propensity score matching.

Table 4 Cycle Outcomes Based on Time Interval from Complete Vaccination to Cycle Initiation

	≤1 Month	>1–2 Months	>2 Months	P-value
Laboratory Outcomes	n = 37	n = 42	n = 71
No. of oocytes retrieved	9.6±7.8	10.8±7.4	9.6±6.7	0.668
Mature oocyte rate (%)	80.6±18.6	86.1±13.7	82.8±19.1	0.374
Normal fertilization rate (%)	71.2±24.4	75.3±19.3	68.8±25.3	0.370
Cleavage rate (%)	98.2±5.7	98.1±5.2	97.4±7.2	0.797
Good-quality embryo rate (%)	29.8±29.5	32.3±29.5	37.2±31.8	0.457
Blastocyst formation rate (%)	72.2±29.7	75.7±29.7	74.9±32.3	0.906
Available blastocyst rate (%)	67.3±33.9	71.6±23.5	74.3±29.1	0.653
Pregnancy outcomes	n = 12	n = 18	n = 36
Biochemical pregnancy rate, n/N (%)	9/12 (75.0)	9/18 (50.0)	25/36 (69.4)	0.269
Clinical pregnancy rate, n/N (%)	9/12 (75.0)	8/18 (44.4)	22/36 (61.1)	0.233
Implantation rate, n/N (%)	12/20 (60.0)	9/28 (32.1)	28/60 (46.7)	0.154

Note: Data are presented as mean ± standard deviation or number (percentage).