Table 1.

Demographic and cycle characteristics and outcomes of COVID vs. control in FET cycles

Group	COVID-19 (N = 41)	Non COVID-19 (N = 41)	p value
Patient age at transfer (y)	31.56 (5.20) [22–42]	31.58 (5.05) [22–42]	0.966
Patient age at retrieval (y)	30.72 (5.00) [23–41]	30.69 (4.73) [22–40]	0.929
Partner’s age (y)	34.79 (6.81) [25–55]	33.31 (5.26) [25–49]	0.396
Smoker	4 (10%)	11(2%)	0.399
Previous retrievals	1.15 (0.43) [0–2]	1.05 (0.47) [0–3]	0.199
Previous transfers	1.42 (0.93) [0–3]	1.11 (0.89) [0–3]	0.103
BMI	25.56 (6.09) [15.43–44.08]	24.78 (6.13) [17.63–41.40]	0.311
Infertility cause			0.738
Age related	2 (5%)	1 (3%)
Male factor	21 (55%)	12 (40%)
Ovulation	3 (8%)	4 (13%)
Mechanical	1 (3%)	2 (7%)
Unexplained	9 (24%)	10 (34%)
Other	2 (5%)	1 (3%)
Parity			0.297
0	18 (47%)	22 (63%)
1	15 (40%)	9 (26%)
≥ 2	5 (13%)	4 (11%)
Gravidity			0.232
0	16 (42%)	21 (60%)
1	14 (37%)	8 (23%)
≥ 2	8 (21%)	6 (17%)
Days from COVID to transfer	59.71 (68.31) [1–274]	NA
≤ 60 (d)	29 (71%)	NA
> 60 (d)	12 (29%)	NA
Protocol			0.013
HRT	16 (39%)	26 (67%)
NC	25 (61%)	13 (33%)
Endometrial width (mm)	9.76 (1.83) [6–15]	9.18 (1.86) [6–13.6]	0.097
No. embryos transferred	1.10 (0.30) [1, 2]	1.12 (0.33) [1, 2]
Day of transfer			0.515
2	1 (2%)	0
3	18 (44%)	21 (51%)
5	22 (54%)	20 (49%)
Embryo grade at freezing			0.438
A	21 (52%)	18 (44%)
B	19 (48%)	23 (56%)
Clinical pregnancy	12 (29%)	20 (49%)	0.070
Pregnancy outcome	12	20
Ongoing pregnancy rate	11 (92%)	19 (95%)
Early missed abortion	1 (8%)	1 (5%)
Implantation rate	27%	43%	0.093
No. oocytes retrieved (original retrieval)	17.58 (9.47) [3–40]	16.71 (8.29) [5–38]	0.800
No. patients who had a fresh embryo transfer (original retrieval)	30	25	0.347
Total frozen (original retrieval)	4.59 (3.31) [1–16]	4.35 (3.24) [1–12]	0.756

Data is presented as mean and (SD) and [range] or counts and (percentage)