The Effect of Freezing Twice during Assisted Reproductive Technology on Perinatal and Neonatal Outcomes
Table 1
Baseline characteristics before propensity score matching.
Characteristic
Study group
Control group
value
Age (years)
29 (26-31)
29 (27-32)
0.075
BMI (kg/m2)
22.781 (19.995-25.038)
22.761 (20.569-25.390)
0.521
FSH (IU/L)
5.84 (4.98-7.038)
6.12 (5.272-7.14)
0.103
LH (IU/L)
5.175 (3.783-7.325)
5.04 (3.74-6.828)
0.558
Number of oocytes retrieved
19 (14-28)
15 (11-19)
0a
PCOS (%)
23 (23.96)
1434 (18.08)
0.137
Regimen of endometrial preparation for FET (%)
0a
Natural cycles
35 (36.46)
4441 (55.99)
Programmed cycles
43 (44.79)
2756 (34.75)
Ovarian stimulation cycles
18 (18.75)
735 (9.27)
Number of transferred embryos (%)
0.209
1
85 (88.54)
6647 (83.80)
2
11 (11.46)
1285 (16.20)
Endometrial thickness on HCG trigger day (cm)
1 (0.9-1.1)
1 (0.85-1.1)
0.813
Previous conception (%)
23 (23.96)
2535 (31.96)
0.094
Values are the median (interquartile range) or number (percentage). aStatistically significant. BMI: body mass index; FSH: follicle stimulating hormone; LH: luteinizing hormone; PCOS: polycystic ovary syndrome; FET: frozen embryo transfer; HCG: human chorionic gonadotropin.
