Table 1 The basic characteristics of the population
Low P+ strengthened LPS (Group A, n = 1295) | Normal P+ routine LPS (Group B, n = 1261) | P value | |
|---|---|---|---|
Age (years) | 31.3 ± 3.5 | 31.4 ± 3.5 | 0.49 |
BMI (kg/m2) | 22.11 ± 3.26 | 21.76 ± 3.13 | 0.005 |
Underweight (< 18.5 kg/m2) | 121 (9.4%) | 170 (13.6%) | |
Normal weight (18.5–22.9 kg/m2) | 733 (57.0%) | 690 (55.2%) | |
Overweight (22.9–27.4 kg/m2) | 339 (26.4%) | 332 (26.6%) | |
Obesity (> 27.5 kg/m2) | 92 (7.2%) | 57 (4.6%) | |
Infertility duration (yrs) | 2.9 ± 2.7 | 2.9 ± 2.6 | 0.58 |
Basal FSH (mIU/ml) | 5.61 ± 1.39 | 5.74 ± 1.43 | 0.017 |
Antral follicle counts | 14.6 ± 7.7 | 13.6 ± 6.8 | 0.002 |
Gravidity | 0.072 | ||
0 | 735 (56.8%) | 671 (53.2%) | |
≥ 1 | 560 (43.2%) | 590 (46.8%) | |
Parity | 0.41 | ||
0 | 1216 (93.9%) | 1174 (93.1%) | |
≥ 1 | 79 (6.1%) | 87 (6.9%) | |
Infertility causes | 0.12 | ||
Tubal | 735 (56.8%) | 768 (60.9%) | |
PCOS | 223 (17.2%) | 172 (13.6%) | |
Male | 124 (9.6%) | 118 (9.4%) | |
Endometriosis | 36 (2.8%) | 35 (2.8%) | |
Other | 177 (13.7%) | 168 (13.3%) | |
Previous IVF failures | 0.43 | ||
0 | 1114 (86.2%) | 1105 (87.5%) | |
1–2 | 67 (5.2%) | 53 (4.2%) | |
≥ 3 | 114 (8.8%) | 103 (8.2%) | |
Ovarian stimulation | 0.19 | ||
GnRHa long protocol | 105 (8.1%) | 118 (9.4%) | |
GnRH antagonist | 214 (16.5%) | 180 (14.3%) | |
PPOS | 976 (75.4%) | 963 (76.4%) | |
Serum estrogen on FET day (pg/ml) median (IQR) | 203.0 (112.0) | 216.0 (123.5) | 0.082 |
Serum P on FET day (ng/ml) median (IQR) | 6.8 (2.3) | 12.2 (3.4) | < 0.001 |
Endometrium thickness (mm) | 9.82 ± 1.84 | 9.82 ± 1.88 | 0.99 |
Number of embryos transferred | 0.063 | ||
Single | 306 (23.6%) | 254 (20.1%) | |
Double | 989 (76.4%) | 1007 (79.8%) | |
Embryo stage | 0.11 | ||
Cleavage | 1079 (83.3%) | 1020 (80.9%) | |
Blastocyst | 216 (16.7%) | 241 (19.1%) |